Deep Dive EV Conversion by Udo Kessler

Johannes Hübner Dr. Udo Kessler Philip Schuster

Deep Dive EV Conversion All you need to know to convert your car to electric

Copyright 2023 by Johannes Huebner, Dr. Udo Kessler, Philip Schuster 1st edition, July 2023 All rights reserved. The information in this book has been researched and prepared to the best of our knowledge and with utmost care. However, no guarantee can be given for correctness, completeness, and relevance. Please do your own research and be aware that you act at your own risk if you use any information from this book. The authors are not liable for any accidents or damage of any kind. The authors are grateful for information on errors, suggestions for improvement and general feedback. You can reach us at feedback@electrifyyourride.info. Disclaimer: Because of budget restrictions we used machine translation for the American English language edition of this Guidebook which was originally published in German. However, a friend who studied English and spends much time in the US and other English-speaking countries helped us with editing the text. Still, you might come across expressions and phrases that may not sound idiomatic or appear incorrect. Our apologies for that and we hope it does not limit the usability and value of this book. We mention several brand names in this Guidebook because these products served us well in our project. No company paid or supported us in any way for being mentioned. All brands mentioned in this Guidebook are copyrighted by their owners. The authors thank Signum communication (www.signum-web.de), Heidelberg, for their support in creating and publishing this guidebook: Art direction: Oliver Weidmann, Thomas Bork Layout: Anja Daum, Jutta Stuhlmacher Lithography: Anja Daum Photo credits: The authors, creative commons: pages 7, 138, 139 Michael Löb, page 140, 141. ISBN 978 3 9825063 1 9 www.deepdiveevconversion.com www.electrifyyourride.info www.openinverter.org

Deep Dive EV Conversion All you need to know to convert your car to electric

Contents Prelude

That’s how it works

Congratulations 6

Chapter 1: Battery boxes

Chapter 4: Electrics and controls

1.1 Plan and build

4.1 The high-voltage system

1.2 Fitting in the modules

4.2 Repurposing the Volvo vehicle control unit

101

1.3 Brackets and mounting

4.3 The CAN Bus

104

Why convert at all? 7

What else

How the climate benefits 8 7 Questions 12 Be a hero – for more than one day 16 4.4 Cable connections Priority 1: Safety 22

Chapter 2: Traction unit

Approval roadworthiness 24

Additional components

2.2 Coupling and mounting the traction unit

Chapter 5: Charging infrastructure

2.3 Inverter board swap

5.1 Preparing and installing the charger

120

2.4 DC/DC converter, junction box, charger

5.2 Wiring the charging socket

122

Chapter 6: Stability and protection

118

The Roadmap 38

3.1 Gas potentiometer, hydraulic pump, vacuum pump

Tools one can’t do without

150

It’s better with music

152

Epilogue

154

126

6.1 Frame reinforcement and impact protection

128

6.2 Splash and stone-chip protection

130

Battery boxes 156 Brackets 162 Cable routings 172 Cooling and heating 184 Impact, splash and stone-chip protection 186 Connectors 194 Second-Life components 195 Abbreviations 196

3.2 Acoustic warning signal, HV heater, mini cooler 91 3.3 Cooling circuit, heating circuit

148

Appendix

Chapter 3: Additional components

Partners to be counted on

4.5 Connecting cables in the engine compartment 112

Components from the Nissan Leaf 30

146

106

2.1 New mounting for the drive shaft Basic parameters Volvo 850 electric 26

And what about the cost?

Chapter 7: Almost there

134

7.1 Communication and display

136

7.2 Test rides

138

7.3 Inspection for road approval

140

Prelude

... to your decision to buy this guidebook! You have taken the first step on the way to an exciting project. And you become part of a growing community of people who want to make their individual mobility more sustainable.

Nevertheless, you should think carefully about whether and in what form you actually want to tackle an electric conversion. Because no matter whether you carry it out alone or with the support of experts – an electric conversion is a very demanding project. This guidebook is intended to help you make this decision on an informed basis. This presupposes that you get a deep insight into the topics that are coming your way – in regard to the skills you need but also from a technical and financial point of view. That’s why we describe the conversion of a Volvo 850 station wagon, built in 1993, in detail. We do not claim to present the perfect solution at every point. However, we are sure that the level of detail gives you a good overview of the small and large challenges you have to master – regardless of the model you want to convert. Ideally, our description will help you to find a practical and safe solution for your project more quickly. For all Volvo station wagon fans of the 850 model series and the first V70 generation, the guidebook can also serve as a guide, although we emphasize: Each project is individual and not everything that we describe can be used one-to-one with other vehicles. There have been too many changes or variants over the years. Of course, with this guidebook, we want to help ensure that the trend of converting classic cars and youngtimers to electric continues to grow. But we are pursuing another goal as well: We believe it is important to expand the conversion horizon and also take a closer look at more recent and current combustion models.

From our point of view, conversions can and must play an important role in the phase of transition to the age of electromobility, i.e. in the next 20 to 30 years. The reason: With conversions, some of the resources invested in the production of combustion vehicles in the past, today and in the years to come can still to be used. This is urgently needed so that the CO2 emissions of individual mobility can be reduced. However, it requires that the conversion process be “industrialized”, i.e. it must be standardized for as many volume models as possible and be feasible at an acceptable cost. We want to give an impetus to this approach with our guidebook. However, the “industrialization” of electric conversions will only succeed if more people – from the car enthusiast without much technical knowledge to master mechanics to software engineers – deal with the topic. The community of private converters and professional conversion experts must therefore continue to grow and stimulate each other – ideally with the support of car manufacturers and suppliers. Against this backdrop, it is understandable why we favor a “second life” or “automotive upcycling” approach for conversions. That way it is possible to achieve the greatest contribution to reducing greenhouse gases and conserving resources in general. That means: Whenever possible, we work with used components, e.g. from Nissan and Tesla vehicles, for the Volvo 850 conversion. We wish you stimulating thoughts and insights when reading this guidebook. And of course good luck with your (possible) project!

Why convert at all? A question that you will certainly get asked by family and friends when you talk about your plans: Why invest considerable time and money to convert an existing vehicle at all? Why not buy a new electric vehicle right away?

The answer in one sentence: The climate needs all the help it can get. And it needs it now. Only then will we hopefully be able to avert the climate catastrophe with natural disasters increasing all over the world, including hurricanes and forest fires in the USA, frequent flooding in Bangladesh, massive landslides in the Italian and French Alps, and the increasingly hot summer temperatures in Germany.

The climate needs all the help it can get

This is why the switch to climate-neutral mobility is so important. And fortunately we are now in the middle of a turning point from combustion vehicles to electric cars (and other alternative drive concepts). In order to implement this paradigm shift as quickly as possible, however, it is not enough just to rely on new vehicles. Given that there are around 48.5 million passenger cars in Germany2 (there are around 1.2 billion worldwide3), it is a “no brainer” from an ecological point of view to save resources by converting some of the existing vehicles to electric and giving them a second life. But what does the carbon footprint of a conversion actually look like? The following chapter answers this question.

In many countries around the world, politicians have understood that mankind must act in the face of the dramatic rise in temperatures. But for the ambitious targets to become reality, buildings, industry, power generation and transport must become emission-free. It depends on each and every one of us. We have to take a critical look at our ecological footprint and reduce it – not least in car-based private transport, which accounts for around 60 percent of CO2 emissions from transport in the EU1 and which, despite many progressive concepts of “shared mobility ’ is likely to continue to dominate in the decades to come.

„Warming stripes“ – Ed Hawkins

Congratulations...

1 European Parliament, Press release, June 14, 2022: CO2 emissions of passenger vehicles: Facts and figures (German). 2 Federal Motor Transport Authority,, Press release No. 10/2022, March 4, 2022: Registered vehicles (in Germany) on 1 January 2022 (German). 3 Federal Energy Agency: Global vehicle figures 1978 bis 2022 (German).

The authors

Prelude

How the climate benefits Automobiles are a masterpiece of engineering and simply fascinating. Therefore, the challenge of an electric conversion alone is a good reason for such a project. But it can also help make individual mobility more sustainable – and ultimately give it prospects for the future.

VOLVO 850 ICE

VOLVO 850 ELECTRIC

VOLVO XC40 ICE

POLESTAR 2 ELECTRIC

CO2-Em/100 km

31.31 kg (10.1l × 3.1 kg)

6.3 kg (18 kWh × 0.35 kg)

14.2 kg (0.142 kg/km × 100)

6.8 kg (19.3 kWh × 0.35 kg)

Mileage 64,250 km (5 years)

20,117 kg (31.31 kg × 642.5)

4,048 kg (6.3 kg × 642.5)

9,124 kg (14.2 kg × 642.5)

4,369 kg (6.8 kg × 642.5)

Vehicle production

0 kg (because in the past)

2,000 kg (due to conversion)

16,100 kg

26,200 kg

Total

20,117 kg

6,048 kg

25,224 kg

30,596 kg

Fig. 1: C omparison of CO2 emissions/equivalents (in kilograms; operating time 5 years).

But to what extent does the climate benefit from electric conversions? On the one hand, conversions help to avoid the CO2 emissions that would result from manufacturing a new car, whether having a combustion or an electric engine. On the other hand, a car that has been converted into an electric vehicle no longer burns conventional fuel. As a result, this reduces the associated CO2 emissions – of course minus the CO2 emissions from generating electricity for the electric vehicle. So far so obvious. But when it comes to the specific calculation of the positive climate contribution of electric conversions, things get a little more complicated. Because the effect is difficult to calculate in detail and depends on the assumptions that are made. As a result, some aspects of the evaluation are up for interpretation. For example, let’s consider the question of how much CO2 the production of an internal combustion engine car (ICE) and an electric car causes.

Previous calculations were clearly too low with a maximum of ten tons. This is indicated by calculations by the electric car manufacturer Polestar from September 2020. According to this, the production of a Volvo XC40 with a combustion engine generates 16.1 metric tons of CO2 and the Polestar 2 electric car generates around 26.2 metric tons of CO2.1

• every vehicle travels 12,850 kilometers a year. This corresponds to the average mileage of a car in Germany in 2021.3

Using the example of our 1993 Volvo 850 GLE, the following options would result:

• the vehicles are driven for 5 years, so the total mileage is 68,250 kilometers each.

1. The Volvo is scrapped2 and replaced by a new combustion engine car, e.g. a Volvo XC40 (purchase price: from approx. 30,000 euros).

• the Volvo XC40 emits – according to Volvo – 142 grams CO2 per kilometer traveled.

2. The Volvo is scrapped and replaced by a new electric vehicle, e.g. the Polestar 2 (purchase price: from approx. 53,000 euros). 3. The Volvo is converted into an electric car and driven for another 5 years (price of conversion: appr. 18,000 euros, not counting personal time invested, page 146). Figure 1 shows the carbon footprints for the individual variants. The figures are based on the assumption that

• the Volvo 850’s internal combustion engine consumes an average of 10.1 liters of petrol per 100 kilometers4 and the CO2 emissions per liter of petrol are 3.1 kilograms.5 • the Volvo 850 electric consumes 18 kilowatt hours per 100 kilometers after the conversion. • The Polestar 2 – according to Polestar – consumes 19.3 kilowatt hours per 100 kilometers (WLTP).

• the production (materials and assembly) of the Volvo XC40 emits 16.1 metric tons of CO2 and the production (materials and assembly, including battery) of the Polestar 2 emits 26.2 metric tons of CO2.6 • the production of the electricity that powers the converted Volvo 850 and the Polestar 2 causes 350 grams of CO2 per kilowatt hour.7 • Second-hand components are largely used for the conversion of the Volvo 850. This means that the electric motor, inverter and, above all, the traction battery are not newly produced, but removed from a damaged vehicle. Nevertheless, the three battery boxes and some other components are specially manufactured or bought new. For this purpose, CO2 emissions are set at a flat rate of 2,000 kilograms for the conversion.

3 Federal Motor Transport Authority, Brief report May 31, 2022: Development of mileages of different vehicle classes since 2017. 4 ADAC Car Test: Volvo 850 GLE, August 1993. 5 The value of 3.1 kg/liter petrol includes both the CO2 emissions when the fuel is burned in the engine as well as in production and transport (well to tank); Incidentally, the value for diesel is even higher at 3.3 kg/liter; see: Auke Hoekstra, Maarten Steinbuch, “Comparison of lifetime greenhouse gas emissions from 1 Polestar, Life cycle assessment: Carbon footprint of Polestar 2, September 2020, p. 20.

electric cars with emissions from vehicles with petrol or diesel engines”, Eindhoven University of Technology, August 2020

2 It is no secret that the alternative to scrapping is export. Since they can hardly be sold in Germany due to demanding emission standards, thousands of older

6 Polestar, Life cycle assessment: Carbon Footprint of Polestar 2, September 2020, p. 20.

vehicles go abroad every year, for example to Eastern Europe and Africa, polluting the environment there.

7 Energy mix Germany 2021, Source: Bundesverband der Energie- und Wasserwirtschaft e.V. (BDEW), August 12, 2022.

Prelude – How the climate benefits

Notes VOLVO 850 ICE: CONVERSION TO ELECTRIC

14,069 kg

NON-PRODUCTION AND NON-OPERATION OF NEW VEHICLE

39,293 kg (Volvo XC 40 Benzin) 30,569 kg (Polestar 2 Elektro)

TOTAL

39,293 kg 44,638 kg

Fig. 2: Savings CO2 emissions/equivalents by converting a Volvo 850 ICE to electric and by non-producing and non-operating a new vehicle (in kilograms; operating time 5 years, mileage 64,250 kilometers).

The example of the Volvo 850 ICE shows that a considerable amount of CO2 emissions/equivalents can be saved – by converting it to electric and by avoiding the production of a new car. The savings will reach 39 tons when the car not produced is a Volvo XC 40 ICE and 44 tons when it is a Polestar 2 electric car.

Let's further assume that every year in Germany only 1,000 Volvos or comparable models from other manufacturers are converted to electric and driven for five years. This would have the following climate effects:10

Talking about savings: Annually they reach at least about 7.9 tons. Incidentally, the savings correspond to a considerable part of the energy-related CO2 emissions per capita in Germany (2022: 11.2 tons).8

• Avoided environmental damage: 7 to 8 million euros

• Avoided CO2 emissions: 39,000 to 44,000 tons

So there are really good ecological reasons for a conversion to electric.

Let us assume that economic and social damages per ton of CO2 emissions are 180 euros9. This means that the conversion of a single existing vehicle such as the Volvo 850 to electric avoids damage to the general public of between 7,000 and 8,000 euros over a five-year period.

8 Federal Environment Agency, CO2 calculator, 2022. 9 Press release “One ton of CO2 causes damage of 180 euros – Federal Environment Agency presents updated cost rates”, November 20, 2018. 10 Not even including the positive economic effects. After all, EV converters are investing a considerable amount of money and thus creating employment, for example if a car workshop is involved in the project.

Prelude – 7 Questions

Befor deciding on your project: Reflect and consider

1. How do you want to use your electric car Let‘s take a look at the driving profile of the authors of this guidebook: Udo drives about ten kilometers to and from the office every day, possibly taking a detour to the supermarket or hardware store. This gives him a daily mileage of 30 to 40 kilometers. At the weekend he does the shopping (approx. 40 km), on Sundays he occasionally drives to the nearby Odenwald forrest (approx. 50 km) or to the Palatinate (approx. 100 km). Considering the range of 130 kilometers of his converted Volvo 850, his usage pattern should not cause any problems. Philip drives eight kilometers to and from the office every day, then an additional six kilometers to his workshop and back again. Including minor detours and errands, the daily mileage is also 30 to 40 kilometers. On weekends, he visits friends with his family and sometimes goes for some 40 kilometers on a scenic route. As his converted Toyota GT 86 offers a range of about 100 kilometers, he can cover around 95 percent of his journeys over the year. For any remaining trips, he uses a Toyota Prius plug-in hybrid. Johannes’ wife drives 18 kilometers to and from work every day. There are also trips to go shopping and to visit family and friends at a distance of around 400 kilometers. After upgrading the battery pack from 24 kWh to 40 kWh, Johannes and his wife used the converted Touran for their annual holiday in Sweden for the first time in the summer of 2021. A tour of 3,000 kilometers in total.

What range do you need based on your driving profile? The answer to this question influences the technical parameters of your vehicle, and thus also which components you need.

2. Where can you charge your car? The answer to this question is closely related to question one: When it comes to charging, your driving profile is what matters most. If you don’t exhaust the range of your vehicle on your daily journeys, i.e. you don’t usually have to rely on public charging stations, you can charge at home overnight using a conventional socket. For your project, this means that you can install a single-phase charger with an output of three kilowatts (kW), which converts the alternating current (AC) from the household socket into direct current (DC) and stores it in your traction battery. That would be the simplest solution in terms of price and technology. Electricity is charged for around 20 kilometers per hour. By the way: An AC phase usually delivers a maximum of three kilowatts, for higher outputs DC current is necessary.

However, if you want to be sure that you can “fill up” with as much electricity as possible as quickly as possible at public charging stations, a different approach is required. Here it is important to distinguish between direct current fast charging stations, which are usually found on motorways, and alternating current charging stations, which are more likely to be found in inner cities. Fast charging stations already include the charger and the vehicle only needs to have the interface for it (CCS, CHAdeMO). These charging stations can charge with outputs from 50 kW to 350 kW, and the journey can usually be continued after a charging time of 20 to 40 minutes. From an electrical point of view, AC charging stations are simply DC current sockets. The charger must therefore be installed in the vehicle. In order not to block the charging station for too long, a three-phase charger should be installed that has an output of at least 11 kW. That would provide a range of about 75 kilometers per hour of charging.

In any case, the technology for electric vehicles will continue to evolve. Traction batteries, for example, become more and more compact and powerful. So higher vehicle weight classes join the ranks of conversion candidates. In addition, solutions have been in the making to keep the electronic comfort and safety features of modern vehicles after a conversion. Age, weight and electrical or electronic systems are therefore not so important when selecting a vehicle. What matters is the condition. On the one hand, this applies to the body, and above all the issue of rust. There are also central components such as axles, brakes, steering and transmissions. They should not only be functional, but in a condition that allows for a further period of use of at least five years. If possible, any repairs on these components and restoration or rust work should be done before the conversion. However, experience has shown that there is always time during the project to work on the vehicle – for example when waiting for the delivery of components. When investigating the suitability of vehicles, approval regulations can also set limits or create hurdles (see also p. 24 and p. 140).

3. Is your vehicle suitable for an electric conversion? In principle, any vehicle is suitable – provided it has a manual gearbox (converting cars with automatic transmissions is also possible, but more complicated). So far, it has been said that only older models, e.g. those built before 1990, can and should be converted. The reasons given are usually the lower weight and the lower share of electronics. That is correct in principle. Less weight and fewer electronics make many things easier. But that doesn’t mean that modern vehicles can’t be converted, too. This point is important against the backdrop of the climate problem. If conversions are to make a significant contribution to climate protection and resource conservation in the medium term, then newer and modern vehicles in particular will have to be converted in large numbers in the future.

4. What do you prefer – second-life or new components? If you only rely on new components, it will be more expensive, but you will usually get there faster. As soon as you know what your electric car should do, you can define the necessary components, obtain offers from suppliers and get started quickly. In contrast, you may need to research the availability of used parts first. And then there is the question of whether the condition and price are right. There is no question that new components are needed for a conversion project – for example for safety reasons (such as high-voltage cables). But the more second-life parts are used the better for the environment and the consumption of valuable resources.

Prelude – 7 Questions

Maybe you are open to the second-life approach. But at the same time you may wonder whether there are enough used components available on the market. Well, please note the following difference. Components such as electric vacuum pumps or hydraulic pumps are definitely easy to obtain, since they are standard components from mass-produced combustion vehicles. At least in Germany and Europe, pre-used electric motors (e.g. Nissan Leaf) and other electric vehicle components (e.g. Tesla chargers) are easily available. However, it may take some patience to find a used Nissan Leaf battery pack at a good price. In our experience, it is therefore ideal to buy a complete vehicle. You have everything in there that you need, and in the end there is even something left over that can be sold again. So Udo sold the Leaf body and thereby reduced the costs quite a bit. All in all, much speaks for the supply of used parts to grow significantly in the coming years. This is due to the fact that more and more electric vehicles are being registered and the number of used and damaged vehicles is increasing accordingly. With ever more new EV models entering the market, the price pressure on used EVs of the first and second generations is increasing, so with some time on hand one can definitely find bargains. In addition, more and more components from EV production models can be used in conversions. This is ensured by the pioneer converters who share their knowledge on the OpenInverter platform (openinverter.org). Components from models including Nissan, Lexus, and Tesla can now be re-used. Finally, each new conversion project expands knowledge and leads to new insights: For Udo’s Volvo project a Webasto high-voltage heater could be used for the first time, because Johannes managed to get the product running thanks to his software knowledge.

5. What space and tools do you have available? In principle, it is true that you can carry out a conversion project in your garage. But it makes things a lot easier if your garage is at least wider than the standard size for a single car. Also, storage room is helpful. Because all too quickly all sorts of parts and components that you have removed or need to install will pile up. In addition, you might need space for a “donor vehicle”. In addition to sufficient work space: You need space for your tools, for example a motor crane and powerful jacks. If you have not previously worked on cars, please reckon with the fact that you will have to purchase and store some pieces of (large) equipment in the course of the project.

6. What are your skills, and what do you need support for? Finally, a crucial question is: What can or do you want to do yourself? The answer is determined by two factors: your skills and the infrastructure you have available. Infrastructure: If your premises are cramped and you do not have the necessary equipment like a motor crane, it is a smart decision to have the removal of the combustion engine, tank and exhaust pipe carried out by a professional workshop. You could also use this opportunity to have end-of-life components replaced such as brake calipers or drive shaft joints. Skills: You grow with your tasks. That’s right, that’s how you have to approach a conversion. But mechanics is one thing, electrics and electronics are another.

Mechanics: In fact, you can do a lot of traditional mechanical work yourself. In some cases, however, specialist knowledge and manufacturing expertise are required – for example, when it comes to connecting the electric motor and transmission or to dimensioning and producing brackets and battery boxes. Electrics: This depends on how you design your conversion. But you will be dealing with a (life-threatening) high-voltage system. You must have special knowledge and apply all relevant safety measures. You should acquire the former before the project and then decide whether you actually want to carry out this work yourself. You must obtain the latter, namely your personal protective equipment and then use it consistently for all work on the high-voltage system. Electronics: Most of the functions and systems in modern vehicles are controlled electronically or with the help of software. This also applies to electric cars. However, the manufacturers do not disclose their software codes. This is why used components, for example from a Nissan Leaf, cannot be transplanted so easily into other vehicles. So the question is: How does communication work in a former ICE car that is going to be equipped with a drive motor and inverter, for example from a Nissan Leaf? In an older vehicle that does not have a CAN Bus, the number of electronic components is manageable and, above all, they are not connected to each other. The anti-lock braking system (ABS), for example, is a completely independent unit and will continue to function even after the combustion engine has been removed. In contrast, all control units in modern vehicles communicate with each other via a CAN Bus. If the main control unit no longer supplies any information from the combustion engine, so-called CAN messages, then the ABS control unit will also not start working. The same applies to traction controls, electric power steering or other devices. A CAN Bus is always an advantage when retrofitting if the CAN messages and their contents are known. In this case, the car can be driven electrically with an additional control unit without having to pull in any additional cables or make any other modifications to the vehicle.

7. Are you willing to invest (a lot) of money and time? You are obviously tempted by the challenge of a conversion. Otherwise you wouldn’t be holding this guidebook in your hands. If you ask yourself why, ideally the answer would be a combination of the following: You are looking for a demanding project. And you want to reduce the ecological footprint of your individual mobility. This means: You can confidently deal with the question of why you are putting money into an “old” car. The same applies to the incomprehension of relatives and friends as to why you spend your free evenings in the garage or workshop after a hard day’s work. Hard cost-benefit aspects should not be the focus of a conversion project. Nevertheless, you should know what costs to expect before you decide to tackle a project. That’s why Udo kept meticulous books and ultimately invested more than 18,000 euros in his Volvo 850 electric. This sum only includes the costs of the actual conversion. That means: If you first have to buy your dream vehicle and possibly have to refresh it technically and optically, then these costs will be added. Investigating the concrete conversion costs, they depend first of all on the donor vehicle or the electrical components such as the electric motor, inverter, traction battery, HV cable and plug. This is the largest block of costs. There are also other individual components such as an electric vacuum pump, a hydraulic pump for the power steering and a heater. The boxes for the traction battery modules, adapter plates and brackets are also important. As a rule, you should be able to buy these parts from a sheet metal work shop or a locksmith, similar to other services related to the electronics and control of your conversion. From the traction battery to the approval process of German authorities, see p. 146 for an overview of all Volvo conversion costs. If you want to be very precise about it, you could also price and include your own work on the basis of an hourly rate. But that would increase the overall bill into completely different dimensions, and it would go against the spirit of a do-it-yourself conversion project.

Prelude – Be a hero – for more than one day

Ambitious Before starting his electric conversion project, Udo was the proud owner of the US version of a Volvo 265, built in 1980. But inspired by the conversion pioneers on the openinverter.org platform, including Johannes and Philip, the decision to sell the vehicle matured.

On the one hand, Udo wanted to make his mobility more sustainable, on the other hand, he’s got ambition: Even if the project actually goes beyond his technical capabilities, he has decided to tackle it – with the support of experts. So he really wants to prove himself. And he is certain: Anyone who converts an existing vehicle and thus extends its useful life is a kind of hero, and not just for one day – as in David Bowie's song “Heroes”. From selling the Volvo 265 (Fig. 1) he redeems 11,300 euros. That was the budget for starting his conversion project. The basic decisions are made quickly: The manual transmission of the conversion candidate and as many used components as possible should be used. As a self-confessed Volvo fan, the candidate for the conversion should be a vehicle of this brand. The choice fell on a Volvo 850, built in 1993, in the rare color “gold” or, according to the Volvo brochure, “beige metallic” (color code 411).

makes sense to re-use the enormous resources that have been invested in existing vehicles for as long as possible by converting them. And indeed: the arguments fall on fertile ground. Udo earns a nod of approval. Since the neighbors are already well informed about Udo’s plans, they are not surprised when a Nissan Leaf (Fig. 2) with front damage is dumped in front of the garage some time later. Udo found the vehicle on an internet platform and bought it while he was on vacation at the North Sea coast. What he didn’t know at the time: The 2016 model year was available in two configurations – one with a 24 kWh traction battery and one with 30 kWh. And it’s the 30 kWh version!

1 Fig.1: Volvo 265, built in 1980: A jewel, no question, but a diesel. Fig.2: Nissan Leaf, year of manufacture 2016: total loss, but definitely still usable. Fig.3: Volvo 850, year of manufacture 1993: before being transported from Fulda to Mannheim.

This lays the foundations for the project: the candidate for conversion and the donor vehicle are in or in front of the garage.

The vehicle (Fig. 3) comes from Switzerland and is – apart from a few scratches and dents – in very good condition as far as body, frame and rust are concerned. With 303,000 kilometers on the clock, the Volvo still starts. But the engine has its quirks. Therefore, the vehicle has to be transported by trailer from the Hesse to the Rhine-Neckar region in Baden-Wuerttemberg. The new (old) Volvo in front of Udo’s garage naturally leads to questions from the neighbors: Electric conversion? What got into him there? Why doesn’t he just buy a new electric car? And Udo is already in the middle of a conversation about why it

3 17

Prelude – Be a hero – for more than one day

As far as Sweden After Johannes had finished his engineering studies, he disliked the idea of having to start the diesel engine of his VW Sharan every morning to drive to work, only a few kilometers. As it turned out, however, this could be avoided quite easily – by cycling.

1 Fig.1: Johannes’ first conversion project: A VW Polo – with a lithium-iron-phosphate battery. Fig.2: Johannes’ (right, his father left) second project – a VW Touran. Fig.3: Johannes’ Touran at a charging station in Sweden.

Nevertheless, the idea was born to convert an internal combustion vehicle into an electric car in order to at least cover everyday journeys. However, it was to take four years before the time had finally come. There were good reasons for this: in 2008 used batteries, motors and inverters from electric vehicles were impossible to find. And new components were only outrageously expensive – a fact that would have immediately put a financial stop to the project.

So, at the end of 2018 there was a rather battered VW Touran, built in 2004, in the driveway and a little later a 24 kWh battery pack from a Nissan Leaf. After almost one and a half years of construction, during which the inverter software was further developed, the end product was ready: An E-Touran with a range of around 120 km, whose storage space was not blocked by any electronic components. The Nissan Leaf battery pack had completely fit into the space of the former petrol tank!

So, Johannes developed one of the most important components himself in his free time: the inverter. Also, a three-phase motor was used, which is more common in large lathes or elevators.

Johannes was finally able to electrically drive the route from Kassel to his former home in South-west Germany, a distance of some 350 kilometers. However, the small 24 kWh battery required a lot of patience when recharging it on longer trips. Therefore, it was quickly replaced by the newer Nissan Leaf battery, which accommodates 40 kWh in exactly the same space. Thus, a range of more than 200 km could be achieved.

In the meantime, lithium-iron-phosphate batteries had come onto the market at affordable prices and so the first conversion could begin. The only thing missing was the vehicle. It had to be small and light, so it became a 1992 VW Polo 86C. The converted vehicle was used until 2020 and covered 40,000 km in that time. But he still owned the VW Sharan with a diesel engine, which had to cover all longer journeys. Due to Johannes’ preference for holidays in Sweden, the vehicle had already accumulated 500,000 km.

3 18

Now the last bastion of the diesel had fallen: the holiday in Sweden. With the fast charging network, which is expanding all over Europe, it was possible to get as far as Östersund in central Sweden. The days of the VW Sharan diesel were numbered, it was sold in 2022, and Johannes is now only driving electrically.

When the Dutch company New Electric donated a Nissan Leaf “Drive Stack” to Johannes, he was able to control it with his self-developed software. The cornerstone for the next project was laid. It should be a vehicle with a slightly higher utility value than the Polo, with more storage space, longer range and fast charging capability.

Prelude – Be a hero – for more than one day

Anything but boring Johannes and Udo’s projects are about converting (boring) everyday models. Philip, on the other hand, is more interested in sports cars. You can already see that in the selection of the vehicle: his first conversion is a Toyota GT86 from 2012.

1 Fig.1: Tuning World Bodensee 2022: The EV86 is voted among the 100 best vehicles at the fair.

When Philip deals with the topic of electromobility, the fan of fast coupés is certain: if it is supposed to be fun, it will be expensive. At the time, the idea that converting an existing vehicle could be a cheaper alternative to buying a new car had not yet arisen. But Philip dives deeper into the topic of e-mobility step by step. He buys a used Nissan Leaf and gains important experience with the technology and practice of the new form of drive. The Leaf proves to be a solid electric car, but from Philip’s point of view, of course, it has significant deficits in terms of driving pleasure. But at the same time it is clear to him that there is potential in the electric motor. You have to know that Philip is a tuning expert for the GT86 and comparable models from Honda and Subaru. He also builds mobile homes for off-road campers in his own workshop as a part-time job. As a result, he is very familiar with metals and the laws of mechanics. And as a qualified IT specialist, he is no stranger to 3D drawings and CAD programs. All in all, the best conditions for a conversion project. Finally, Philip is offered a Toyota GT86 with engine failure. That’s when it clicks: The idea for a conversion with Leaf and other predominantly used components takes hold. What appeals to him about it: In view of the limited installation space in the Toyota, he has to break new ground in practically every respect. Existing solutions don’t work.

Let’s take the distribution of the 24 kWh traction battery as an example. In painstaking detail (not least with the help of 3D drawings), he accommodates the capacity in four places in the vehicle despite all the limitations: in the spare wheel well, in the place of the tank and in the engine compartment under and next to the electric motor. The aim is not only to have sufficient power available in the Toyota. It is just as important to achieve a balanced weight distribution between the front and rear axles. Philip did that. With 51 percent at the front and 49 percent at the rear, the ratio is ideal.

Fig.2: Absolutely tidy – the engine compartment of the EV86. Fig.3: Dynamic appearance with style: Philip had the rims of the EV86 painted in “High Voltage” orange.

Another challenge: Important driver assistance systems such as ABS and ESP as well as the other electronics must be retained in the Toyota – without the original engine control unit, which can no longer be used. Together with Johannes, Philip is developing a new control unit based on a standard microcontroller. The two manage that: not only can all important information for the operation of the vehicle be sent to the CAN Bus and processed further, for example battery voltage, power, speed. With the help of the controller, it is also possible to get more power out of the Leaf engine. The torque increases from 240 Nm to 370 Nm. This makes the EV86, as Philip now calls his Toyota, not only extremely “dynamic” (from zero to 100 km/h in 6.7 seconds), but also a born drifter. Therefore, the driving fun is really not neglected. At least that shows the broad grin that Philip has on his face when he drives the EV86 through the hilly landscape of the local Swabian Jura. Anything but boring, that is.

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Prelude – Prio 1: Safety

Danger High Voltage!

Head: Helmet with face protection, protection class 1, i.e. electrical insulation up to 1,000 V AC and protection against accidental arcing up to 4 kA/0.5s according to standard EN 61482-1, e.g. from CATU.

There is no question that converting a vehicle to an electric drive is a sensible project. But it is also associated with risks to life and limb. Because we are dealing with an invisible danger – electricity.

In electromobility in Germany, voltages of more than 60 volts (direct current) or 30 volts (alternating current) are considered high voltage (HV). HV systems can be recognized by the fact that their components are provided with warnings: A black flash on a yellow background in a triangle with the note “Caution High Voltage” or “Danger High Voltage” and the cables must be designed in the signal color orange . The greatest dangers emanating from HV systems are electric shocks, but also electric arcs. The latter are caused by the disconnection or connection of electrical circuits under load, as well as by short circuits or damaged components and insulation. If an electric shock or arc occurs, this often triggers reflexive movements and thus secondary accidents. Those affected may fall and also suffer abrasions or other injuries.

Strength of current However, the decisive factor for the danger from HV systems is not the voltage, but the current strength (amperage). In the HV system of our Volvo conversion, for example, currents of up to 255 amps flow. However, even a few milliamps are life-threatening for our body. So, is it better to keep your hands off such a project? You should ask yourself this question seriously. Please only decide on a conversion project if you are willing to deal intensively with the subject of safety. That means you need to identify and implement precautionary measures, and you need to invest in professional protective clothing. Of course, it would be best to have experienced experts teach you how to work on HV systems in person. However, at least in Germany, such qualifications have not yet been offered to private individuals, but only to employees in sectors such as the automotive trade. However, the websites of insurance companies and professional associations also provide a good overview of safety measures and the necessary equipment.

We have summarized what the personal protective equipment for working on the HV system should look like on the opposite page.

Disassembly

Clothing: Jacket and pants with a high proportion of cotton. Synthetic fibers such as polyester or polyamide are not suitable because they are not flame retardant. Arc-fault-proof clothing according to the EN 61482-2 standard is ideal, e.g. from CATU.

Hands: Insulating gloves up to 1,000 V AC according to the EN 60903 standard, e.g. from Honeywell.

Tools: Insulated screwdrivers, socket wrenches, etc., e.g. from Wiha.

Shoes: Safety shoes with insulating soles for electrical protection up to 1,000 V AC according to the EN ISO 20345:2011 and ASTM F2412-11-11 standards, e.g. from Gaston Mille.

In most cases, you first come into contact with HV technology in a conversion project when you have to remove or open the battery pack of a donor vehicle (p. 30) If you have purchased a donor vehicle, the first thing to do is make sure the service plug is pulled and the negative 12 V battery cable is disconnected. Please keep car keys and service plug separate from the vehicle in a place that only you can access. And before each operation on the HV system, please check whether the service plug is actually pulled. But be careful: a removed service plug does not offer absolute safety. The HV system may be switched off from power supply. Nevertheless, the individual modules or cells of the HV battery are still live. So exercise caution even after pulling the service plug. For example, while unlikely, it is not impossible to touch both the positive and negative terminals of a module unit at the same time. What you definitely need and can usually find online is the workshop manual for your donor vehicle (the owner’s manual is not sufficient). The document is important because it not only contains detailed information on the structure of the battery pack, but also on its disassembly. After reading the details, you can assess whether you can safely carry out the dismantling of the traction battery in your working environment (your private garage). If in doubt, have the work done by a specialist company that is familiar with the model of your donor vehicle.

PRECAUTIONS FOR WORKING

AND PLEASE ALSO THINK ABOUT

ON THE HV SYSTEM:

SAFETY IN OTHER WAYS:

• Familiarize yourself with the donor vehicle’s HV system and the manufacturer’s safety instructions. • Pull service plug or check if it has been pulled. • Check the absence of voltage according to the 3-point rule: check the measuring device, measure the absence of voltage, check the measuring device again. • Only work on the system with protective clothing. • Check protective clothing, e.g. insulating gloves, for tears and holes. • Never touch unprotected HV cables and components. • Check the HV cable and battery for external damage.

• Eyes and ears: Wear earmuffs and goggles, e.g. when drilling and flexing. • Lighting: Provide good light, e.g. with the help of construction spotlights, in addition to the garage lighting; Use a headlamp for detailed illumination. • Working environment: Ensure a comfortable room temperature (approx. 20 degrees Celsius). • Hands: Wear work gloves to avoid cuts, tears and scratches. • Order: Only keep the parts and tools that are required for the next work step. • Four eyes see more than two: working with a friend increases safety.

Prelude – Approval roadworthiness

Approval roadworthiness Approval regulations for EV conversions vary from country to country. In Germany, the TüV Association’s publication titled "Electric vehicles in the individual approval process" is the relevant document.

The TÜV Association was formed by several vehicle inspection organizations to improve the safety of vehicles through independent assessments and by educating all parties involved in road safety. Therefore, It is definitely worth working through the document before starting a project.

On the other hand, the specific approval requirements help to focus on quality and thoroughness from the start. In this respect, the criteria of the TÜV publication are relevant for every conversion project – regardless of whether it is carried out in Germany or in any other country.

On the one hand, this increases the chances of getting the vehicle approved without complications and delays. After all, who likes to rework after months of "blood, sweat and tears" have flowed into the project? The benevolent nod of the test engineer is to EV converters what the Oscars are to actors in Hollywood – the official recognition of having achieved something extraordinary.

Fig. 1 shows the table of contents of the TÜV publication. Each point must be addressed in the documentation of an EV conversion. This requires effort, but it also accelerates the acceptance process. However, in Germany the documentation of an EV project is required before getting an appointment for the approval process at all.

1 PERSONAL PROTECTION DURING THE APPROVAL PROCESS 2 BASICS / REQUIRED DOCUMENTATION 2.1 Vehicle data before conversion 2.2 Vehicle data after conversion 2.2 High-voltage safety concept 2.3 Criteria for applicable regulations 3 FUNCTIONAL SAFETY 3.1 Relevant content of the Low Voltage Directive 3.2 Functional requirements 3.3 Dimensioning the drive system 3.4 Minimum state of charge of the energy storage device 3.5 Heating/ventilation and defrosting, drying 3.6 Brake 3.7 Steering 3.8 Basic function of the electrical systems 3.9 B attery (Rechargeable Electrical Energy Storage System, REESS) and battery management system (BMS) 4 ELECTRICAL SAFETY 4.1 Protection against direct contact 4.2 Identification of high-voltage components 4.3 Insulation fault monitoring 4.4 Separation of high-voltage circuit 4.5 Design of the high-voltage network 4.6 High-voltage disconnect 4.7 External power connection

5.3 Overload protection 5.4 Energy storage cover 5.5 Voltage shutdown in the event of a crash 5.6 Removable energy storage 6 FUEL CELL SYSTEM (NOT APPLICABLE) 7 ENVIRONMENTAL PROTECTION AND SUSTAINABILITY 7.1 Electromagnetic compatibility (EMC) 7.2 Exhaust emissions, CO2 emissions, fuel consumption, electricity consumption and range of electric hybrid vehicles 7.3 Power consumption and range of pure electric vehicles 7.4 Noise emissions 7.5 Energy storage 8 ENGINE PERFORMANCE 9 PERSONAL PROTECTIONS 9.1 Occupant protection 9.2 Protection of third parties (maintenance/testing, repair, rescue services) 9.3 Charging process 9.4 Guarantee of perception, protection of weaker road users 10 GENERAL ASSESSMENT CRITERIA AND CHECK POINTS 11 USER MANUAL, SAFETY CONCEPT 12 APPENDIX

5 ENERGY STORAGE SAFETY 5.1 Ventilation (DIN VDE 0510, UN Regulation No. 100) 5.2 D esign features/installation conditions/installation location

Fig. 1: Contents of the TüV Association publication "Electric vehicles in the individual approval process" (August 2021).

Prelude – Basic parameters Volvo 850 electric

Key indicators and variables Motor: 180 kg Exhaust system: 20 kg Tank (with contents): 70 kg Components (generator, servo pump, cooler, etc.): 30 kg

Electric motor: 55.0 kg Inverter: 15.0 kg DC/DC Converter: 3.4 kg Charger: 15.2 kg Battery boxes 1–3 (modules and holders): 246.6 kg Frame reinforcement rear: 3.2 kg Impact protection rear: 1.5 kg Charging cable: 2.9 kg Splash protection front: 2.3 kg Stone chip protection underbody: 3.1 kg Acoustic warning signal with holder: 1.0 kg Aluminum plate: 4.5 kg Hydraulic pump with holder: 5.0 kg 2 water pumps with holders: 3.0 kg Vacuum pump with holder: 1.8 kg HV heater with holder: 3.0 kg Cooler with holder: 1,0 kg Adapter plate gearbox: 1.8 kg Adapter plate electric motor: 0.9 kg Holders electric motor: 5.5 kg Spacer rings (5) transmission/electric motor: 2.3 kg

300 kg

378 kg

Volvo 850 ICE

Volvo 850 electric

The power of the electric motor of our donor vehicle is 80 kW, the battery capacity is 30 kWh. What does that mean for the basic parameters of the Volvo 850 electric – including weight, weight distribution, charging time, range and top speed?

Weight and weight distribution Important and possibly limiting factors in a conversion project are weight and weight distribution. As a rule, neither can be maintained: The converted vehicle becomes heavier and the weight distribution usually shifts from front to rear. These are the reasons for this change: In the original condition of the combustion vehicle, the front axle carries more weight than the rear axle, mainly due to the engine. In the case of an electrical conversion, however, a light electric motor is installed and a (considerable) part of the heavy traction battery is usually placed in the rear. This applies to the Volvo conversion, too.

This increases the curb weight of the Volvo from 1,450 kg to around 1,528 kg (excluding the driver). With a permissible total weight of 1,970 kg, the possible payload drops from 520 kg to 442 kg. However, five people can still be transported, because expert organizations in Germany calculate a weight of 75 kg per person and 5 kg of luggage (5 x 80 kg = 400 kg) for the approval of the conversion. So, we have 42 kg left before reaching the maximum payload.

Fig. 1: Removed vs. added components – Volvo 850 ICE vs. Volvo 850 electric.

This is not a problem as long as the permissible rear axle load is not exceeded. With the Volvo we are still a long way from that (max. 1,010 kg). However, we counteract the higher load on the rear axle by installing reinforced springs and we raise the vehicle about 50 mm. In order to avoid weight and weight distribution becoming an issue in your project, consider early on which components are being removed or installed, what their weight is and where they are installed in the vehicle. As a rule, the engine and auxiliary units (e.g. cooler, generator, servo pump) as well as the exhaust system and the tank will be taken out. In the Volvo the removed parts added up to around 300 kg opening up space for an electric motor, inverter and HV batteries, among other things, in the engine compartment as well as in the trunk and rear. The installed components weigh around 378 kg (Fig. 1).

Charging time

i LOAD CAPACITY OF THE TIRES: The curb weight of the Volvo does not increase dramatically as a result of the conversion, but it is significant. It is therefore worth checking the load or load index of the tyres. Information is provided by the identifier on the tire wall – on the Volvo “195/60 R15 92V”. The number “92” stands for a load capacity of 630 kg. With four tires, this results in a maximum load capacity of 2,520 kg. Since this value is well above the permissible total weight of 1,970 kg, we are on the safe side.

Due to his driving profile, the time does not play a decisive role for Udo, as he will be charging his car at a charging station (wallbox) at home. Therefore, a Type-2 charging socket and the 11 kW charger from Tesla are sufficient for his needs. This means: If the Volvo enters the garage in the evening with a residual energy of 2,450 Wh (10 percent of the available capacity of 24,500 Wh) and is plugged in to the charging station, the traction battery will be recharged after two hours: • Charging capacity of the Tesla charger: 183 Wh/min. (11,000 W : 60) • Energy to be recharged: 24,500 Wh – 2,450 Wh = 22,050 Wh • Charging time: 22,050 : 183 = 120.5 minutes

But let’s assume Udo had a driving profile in which longer distances should also be covered in an acceptable time. Then we would have installed the CHAdeMO connector from the Leaf donor vehicle. This allows for using different charging speeds – bypassing the Tesla charger. However, please keep in mind that you cannot charge a lithium-ion battery up to 100 percent with high performance and that the charging performance depends on the ambient temperature. Comparing the charging performance of various Nissan batteries shows that the 30 kWh battery is a good choice for fast charging. It shows the best charging curve: up to 80 percent (19,600 Wh), the battery charges practically with 45 kW – that means: 750 Wh of energy flows per minute. So, if we connect to the charging station with 10 percent remaining energy (2,450 Wh) we reach 80 percent of the available battery capacity in just 23 minutes.

Prelude – Basics Volvo 850 electric

Let’s take a look at the following example based on these values (Fig. 2 and Fig. 3): Udo plans to visit Johannes in the summer. The distance is just around 260 kilometers. The cruising speed on the German Autobahn, which covers almost the complete distance, should be 120 km/h, and Udo starts with a fully charged battery (24,500 Wh). The Volvo 850 electric covers 110 km before the first charging stop (24,500 Wh – 2,450 Wh = 22,050 Wh : 200 Wh/km = 110 km) after a driving time of 55 minutes. Recharging to 80 percent battery capacity (19,600 Wh) takes 23 minutes. After traveling additional 85 kilometers (19,600 Wh – 2,450 Wh = 17,150 Wh : 200 Wh = 85 km) and after a driving time of 44 minutes, Udo has to recharge again (23 minutes). Udo covers the remaining distance of 65 km in 33 minutes.

he can cover his daily commute in an environmentally friendly way with his Volvo 850 electric without recharging. And that is undoubtedly the case with a daily mileage of just 40 kilometers. This means that he can conveniently recharge the required energy overnight at his charging station at home. But even if his commute were 60 kilometers, that would be feasible in the configuration of the Volvo 850 electric – even without the possibility of recharging at the destination. Even in winter, the range would be around 138 km at a speed of 90 km/h (24,500 Wh – 2,450 Wh = 22,050 Wh : 160 Wh/km = 138 km).

The trip takes just under three hours to reach the destination: 55 min + 44 min + 33 min = 132 min, charging time: 2 × 23 min = 46; Total: 178 min = 2 h 58 min At the destination, the battery still has a range of 20 kilometers. Almost three hours for a distance of 260 kilometers – that would undoubtedly be faster with a combustion vehicle – provided the traffic situation on Germany’s congested Autobahns allows it. But with our Volvo conversion, a short-distance driving profile is in the foreground. It is important for Udo that

BATTERY KNOWLEDGE A battery ages about five times faster if it is charged to 100 percent instead of 80 percent. Therefore, most battery management systems (BMS) do not allow charging to 100 percent, but limit it to 90 percent (but display 100 percent). If the daily mileage, for example the commute to work and back, is between 30 and 60 km, we only need part of the battery capacity. It therefore makes sense to set the charging limit at 80 percent. The charge status of the battery “oscillates” between 60 and 80 percent – optimal!

Reichweite langstrecke mit dem volvo 850 electric (Voraussetzung : chademo-anschluss

110

distance (kilometers)

195 charging

trip time (minutes)

Fig. 2: Long-distance rides with the Volvo 850 electric; CHAdeMO connection required.

260

122

145

SUMMER 90 KM/H

SUMMER 120 KM/H

WINTER 90 KM/H

WINTER 120 KM/H

Small car

110 Wh/km

170 Wh/km

140 Wh/km

200 Wh/km

Station wagon/Minivan

140 Wh/km)

200 Wh/km

160 Wh/km)

240 Wh/km

Van/Bus

190 Wh/km

270 Wh/km

230 Wh/km

330 Wh/km

Fig. 3

Range Apart from the battery capacity, the range depends on other factors such as driving behavior or vehicle type: • How can the driving be characterized – normal or sporty? • Does the driver usually sit alone in the vehicle or with passengers? • What electrical equipment in the vehicle has to be powered and how often is it used (e.g. heating, windshield wipers, air conditioning)? • Will the vehicle be driven with special electric car tires or not? But there are also some fundamental influencing factors. These include air resistance and outside temperature. Drag is determined by the vehicle’s aerodynamics. Generally speaking, this means that a high vehicle consumes more energy than a low one. The Volvo 850 station wagon is somewhere in between: not as efficient as a small car, but more efficient than a van or bus. The following applies to the outside temperature: Colder air has a higher mass, which affects the air resistance. Cold batteries have less usable capacity than warm ones. And last but not least: When the temperature is cool or in winter, we use the heating. The bottom line is that when the outside temperature is just under zero degrees Celsius, we need about 20 percent more energy than at 25 degrees Celsius. These basic principles and test drives by YouTuber Bjorn Nyland (with 100 EVs at different times of the year and at different speeds) result in empirical values for energy consumption (Fig. 3). In order to be able to calculate the range, however, we still need to know the actually usable battery capacity.

charging

SEASON SPEED

178

Nissan releases around 90 percent of the Leaf capacity for use. Since we are using a used battery, it no longer has the full released capacity. In our example, we are assuming 91 percent remaining capacity (State of Health, SoH). This results in the following calculation: E = 30 kWh × 0,9 × 0,91 = 24.5 kWh or 24,500 Wh.

However, this is not the available battery capacity. When the charge level reaches 10 percent (2,450 Wh), the drive battery should be recharged. Therefore, the usable capacity is: E = 24,500 Wh– 2,450 Wh = 22,050 Wh The range can be calculated on this basis, for example for the option “Station Wagon/Minivan, Summer, 90 km/h”: Range = 22,050 Wh : 140 = 157 km In winter it would be about 20 kilometers less at 90 km/h. Note that the importance of variables such as air resistance and outside temperature becomes quite apparent: In summer, a small car going at 90km/h only needs a third of the energy that a van or bus uses in winter riding at 120km/h: 110 Wh vs. 330 Wh.

Maximum speed While the maximum speed was understandably an important issue for Philip when converting his Toyota GT 86, it only played a subordinate role for Johannes and his VW Touran. And top speed is not a decisive factor for Udo either. But it is still important to know how fast the Volvo 850 electric can travel, for instance when overtaking another car. The power of the electric motor of 80 kW enables a maximum speed of up to 145 km/h in the Nissan Leaf. This top speed is achieved without a classic gearbox practically in first gear. The engine rotates at 12,000 revolutions per minute (rpm) and is then curtailed. In our conversion, however, we have a manual gearbox. We will therefore limit revolutions to 7,000 per minute so as not to overload it. Usually we will drive in third gear – up to a speed of approx. 100 km/h (at approx. 4,200 rpm). If we want to drive faster, we engage fourth gear at the start of the journey. Then we reach a top speed of 130 km/h (at approx. 4,000 rpm). The performance is maxed out here, and it doesn’t go any faster in fifth gear.

Prelude – Components from the Nissan Leaf

Rich prey Conventional wisdom has it that for converting an ICE vehicle one basically needs an electric motor and a battery pack. You guess it: Much, much more is necessary. That is why it makes sense to buy a donor vehicle.

Then the necessary components are available from one source and all at once. This is most likely less expensive than purchasing the various parts individually. It also helps to accelerate the project as less time is spent researching and ordering components. Of course, it can also take some time and effort to find a suitable donor vehicle. But once it’s located in your garage, things are a lot easier to re-use. Our “donor” is a 2016 Nissan Leaf with front damage, a mileage of 102,000 kilometers and a State of Health of the traction battery of 91 per cent. We bought this car for 5,900 euros, and sold it later for 1,500 euros – without its 30 kWh battery, electric motor, inverter, BMS and other components. So all of this cost 4,400 euros. A bargain without a doubt. The challenge, however, was to remove the required components from the Leaf. Because of the damage to the front, it wasn’t that easy. In some places, we had to use the angle grinder to gain access – for example to reach the screws of the powertrain unit including electric motor, inverter, charger/DC-DC converter, and gearbox. Before starting with the removal of components, it is certainly worth watching technical videos about the donor vehicle on online platforms. We also recommend consulting the manufacturer’s manuals. With the Leaf, the “EVC – EV Control System” and “TMS – Traction Motor System” sections of the “Nissan Leaf Service and Repair Manual”, June 2014 edition, helped us a lot. The greater the knowledge about the processes, the better. It starts with loosening the plug connections. In addition, special tools are required for some work steps. And finally you have to consider: If you don’t work professionally, the required parts can be damaged during removal. In addition, keep your safety in mind when dismantling a vehicle. So, if possible, follow the manufacturer’s instructions step by step.

1 Fig. 1: The traction battery in front of the Leaf. The required trolley jack can be seen under the vehicle.

TOOLS Flat bar or lever Straps Euro pallet Trolley jack Soapy water Roller boards Wrench size 13 (insulated) Carpet cutter

Fig. 2: Despite front damage: what we need is not damaged. Fig. 3: The “exposed” drive unit.

MATERIAL From the Leaf donor vehicle: Acoustic warning sound Traction Battery Electric motor Cables, plugs Cooling Gearbox hub Screws Contactors from Power Delivery Module (PDM, charger /DC-DC converter as reserve) Water pump Inverter

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Prelude – Components from the Nissan Leaf

In focus: the battery pack In retrospect, it would have been a lot easier to ask some official Nissan garage to dismantle the Leaf. This applies in particular to the battery system. Although the process is described in the Leaf manual (section “EVB – EV Battery System”), it cannot be carried out in a residential garage. Usually, there is no lifting platform or pallet truck available to move the battery around, which weighs around 300 kg. So how do you take down the battery pack? The idea: place a wooden pallet under the vehicle and fill in the gap to the battery with pieces of hard polystyrene. After loosening the screws (12 units), the battery pack then has almost no distance to cover until it rests (Tab. 4-5). Said and done. But how do you get the drive battery out from under the vehicle?

Step 1: The Leaf must be raised so that the distance between the ground and the lower edge of the vehicle is approx. 35 cm. A normal car jack is not sufficient for this. It is essential to use a hydraulic trolley jack with the appropriate lift.

Step 2: Pull out the hard polystyrene elements piece by piece so that the battery rests directly on the pallet.

Step 3: Loop straps around battery and pallet.

Step 4: Spread soapy water on the garage floor.

Step 5: Pull out the battery from under the vehicle.

Nissan Leaf Battery – Deep Dive” by Prof. John D. Kelly from Weber State University in Utah, USA. The cover of the battery is screwed and glued to the lower part of the housing. The screws are quickly loosened. The approx. 35 mm wide adhesion must be cut through with a thin blade, for example a carpet cutter or Stanley knife (Fig. 6). This will take some strength and use some blades. But after about 45 minutes, this job should be done. Incidentally, there is no risk of penetrating the interior with the blade. Note that there is no access to the modules at the connection point between the cover and the base. If the adhesive is severed, insert a flat iron into the gap and pry open the cover piece by piece – and enjoy the uplifting moment when you first see the modules (Fig. 7). But despite all fascination with this technology:

Fig. 4: The plug unit (connector flange) of the traction battery seen from the engine compartment of the Leaf.

Fig. 5: The 300 kg traction battery on the pallet before being pulled out from under the vehicle.

Fig. 6: Sweaty – loosening the bond between the cover and the lower part of the housing.

Fig. 7: Looks good – the inner workings of the traction battery.

Fig. 8: Acceptable – with a voltage of 345 volts, the battery from 2016 is around 15 volts below the nominal output.

Fig. 9

! PLEASE WEAR PROTECTIVE CLOTHING AND USE INSULATED TOOLS WHEN WORKING ON THE TRACTION BATTERY Before we start dismantling, please carry out a stress test. Everything should be fine with the battery (at least that’s what the display in the vehicle suggested). But we wanted to be on the safe side and measure it (Fig. 8). To do this, we connect – with the service plug removed – the positive pole of our multimeter to the positive pole of the rear stack (12 modules) and the negative pole to the negative pole of the RH front stack (6 modules) – all in protective clothing, of course! Then we plug in the service plug. The multimeter reads 345 volts. In view of the service life of the damaged Leaf, a voltage loss of around 15 volts is an acceptable value. We are pleased with the outcome.

When the battery was later relocated to roller boards to be able to move it more easily in the garage, we couldn’t help but notice that it would have been smarter to put the roller boards under the battery right from the start. Then we could have avoided applying soapy water on the floor. But as the saying goes: hindsight is easier than foresight .

Open sesame After removing the dust from the black cover, the drive battery shines in the glow of the garage lights like a treasure chest that only needs to be opened. But please be careful now as well, and use great care and caution. Before you start, you should learn about assembly and disassembly. You can find numerous videos online under the search term “Nissan Leaf Battery Disassembly”. One is particularly recommendable: The “2011

i KEEP EVERYTHING To reuse as many parts as possible, follow this basic rule: Dismantle everything as if you had to put it back together again. Pick up all screws and do not cut through any cables, but loosen them. Some cables and several screws are absolutely necessary for the conversion project.

Prelude – Components from the Nissan Leaf Dismantling modules and components Before further dismantling the traction battery, it is recommended to re-watch the videos mentioned above, re-read the Leaf manual (e.g. EVB-204/205, EVB-30/31) and ask yourself: Am I secure? In the first step, please pull the service plug and disconnect the HV connections so that the individual module units (rear stack, RH front stack, LH front stack) are separated from each other. Then, piece by piece, loosen the screws with which the individual parts are attached to the lower part of the housing and remove the components.

Unscrew the three module units and carefully lift them out with the motor crane. Unscrew the service plug unit, pull out the BMS cable connections and remove the unit.

Clip on the orange protective flaps, e.g. here.

LH Front Stack

Loosen and remove the connector flange at the front.

Disconnect and isolate the cables on the plus and minus poles of the “rear stack”.

Rear Stack

RH Front Stack

Detach the “Battery Junction Box” (BJB) from the connector flange on the front, detach the fasteners on the body of the housing, and remove the BJB.

Disconnect and remove the cables at the negative pole of the “Battery Junction Box” (BJB) and at the negative pole of the “RH Front Stack”.

6 Loosen and remove the cable on the positive pole of the “Battery Junction Box” (BJB).

Loosen and insulate the cable on the positive pole of the “LH Front Stack”.

Loosen and remove the orange-coated copper rail (“busbar”) between the negative pole of the “LH Front Stack” and the positive pole of the “RH Front Stack”.

Prelude – Additional components

Closing functional gaps Thanks to the Leaf donor vehicle, we already have the essential components of an electric vehicle. Nevertheless, there are some gaps that we have to fill.

Since the internal combustion engine is no longer available, we lack the vacuum for the brake booster and the drive for the servo pump. We solve the vacuum problem with the help of an electric pump, which is used in millions of vehicles (Fig. 1). Adding an electric hydraulic pump that is also widely used, we ensure a constant flow of oil for the power steering (Fig. 2). The conversion will also change the way the Volvo accelerates. We continue to use the throttle cable and its bracket in a modified form (p. 88). But we need a gas potentiometer (Fig. 3). This is a standard product, like the two pumps, and it is easy to obtain on the resale market. Our recommendation: If possible, buy used parts with both the holder and the wiring. Replacing the large Volvo cooler and fan is just as simple. We will continue to have a cooling circuit. But the cooling capacity can be significantly lower. A mini cooler (Fig. 4) is sufficient.

Last but not least: along with the combustion engine, we have also removed the tank. So there is no longer a filler neck behind the tank cap, but a Type 2 charging socket (Fig. 10) for plugging in the charging cable.

Fig. 1: Vacuum pump with sensor.

Fig. 2: Hydraulic pump.

Fig. 3: Gas potentiometer.

Fig. 4: Cooler.

Fig. 5: Webasto HV heater Webasto.

Fig. 6: Water pump heating circuit.

Fig. 7: PDM.

Fig. 8: Tesla charger.

Fig. 9: Tesla DC/DC converter.

Fig. 10: Type 2 charging socket.

Fig. 11: Drive shaft bracket.

Finally, please don’t forget: It might be true that some items to be removed from the Volvo are no longer needed. However, some pieces may still be used later-on. These include the drive shaft bracket (Fig. 11) that was attached to the rear of the combustion engine, as well as some engine brackets and the engine wiring harness. As mentioned before, it makes sense to apply the principle of not disposing or selling anything before the project has been finished.

It gets trickier when it comes to heating. We need a solution here, since the waste heat from the combustion engine is no longer available. We opt for a high-voltage heater from Webasto (Fig. 5). We also need an aftermarket water pump for the heating circuit (Fig. 6). In theory, our Leaf donor vehicle already provides a charger and a DC/DC converter for re-use. Nissan calls this unit the “Power Delivery Module” (PDM, Fig. 7). We couldn’t use it, however, as it sits on top of the electric motor and inverter, and the overall unit was too tall for the Volvo’s engine bay. Alternatively, we procured a charger (11 kW, Fig. 8) and a DC/DC converter (Fig. 9), each from a Tesla Model S (2015).

Prelude – The Roadmap

Plan your project The electric conversion of a car is a highly complex project which requires a well-planned approach. Despite all planning and preparations, surprises and errors may happen in all stages. But hopefully such challenges will be limited.

Planning • Identify partition of traction battery capacity depending on space and weight distribution in the vehicle: number of boxes, number of modules per box, dimensions of boxes, brackets for boxes, length of HV and BMS cables. • Place e-motor and transmission in engine compartment to identify their final position, including coupler, spacer rings, adapter plates. • E-motor/gearbox brackets: Which ones to be used further, which ones to be created new from scratch? • Putting inverter on e-motor to define position of DC/DC converter and junction box (on aluminum plate). • Aluminum plates (large, small): dimensions and number of holes. • Configure junction box: dimensions, cable routing, holes, fuses. • Define location of additional components. Which components bring brackets with them, which brackets have to be created?

Sourcing 2 Thanks to Johannes’ and Philip’s conversion experience, we were able to create a roadmap at the beginning of the Volvo project. In the roadmap, we have defined the essential project phases. This plan served as an important guide to reassure ourselves from time to time: What has been achieved? Are we still on track? In any project delays are likely to happen. For instance, it may not be possible to obtain a particular part or tool, or a component does not fit and has to be re-ordered or re-produced. In such cases, the roadmap proves to be helpful, too. If there is a problem at any point, the plan quickly tells us which other task we can work on instead.

So, do not expect to follow a project roadmap to every detail during execution. No doubt, some tasks need to be carried out in sequence. Still, the roadmap provides a certain level of flexibility regarding the progression of the tasks at hand. In addition, the order and structure of the chapters in the “How it works” section provide an overall impression of the project phases. Also, we repeatedly point out when certain tasks have to be completed to avoid any duplication of work.

Technical tasks, project execution Preparation

Initial Phase • Donor vehicle or individual components? Second Life or new components? • Determine curb and maximum weight of conversion candidate, as well as weight distribution, axle loads, ground clearance. These are important for comparing the vehicle before and after the conversion. • Identify desired range and preferred type of charging (f. ex. wall box at home). This can influence the capacity of the traction battery and the charging infrastructure.

•R emove engine, tank, fuel lines, exhaust system. •R etain drive axle bracket, motor brackets, wiring harnesses, connectors, clips, rubber boot of fuel filler neck, cooling circuit hoses/clamps. •R emove bumpers, wheel housings, trunk lining, seats, carpet, front mask. • I f necessary: carry out repair work on vehicle body.

Sourcing 1 • Purchase donor vehicle, individual ev components or conversion kit (if available). • Research and order additional components, e. g. vacuum, hydraulic, water pumps, heating system (depending on how the heating is to be done).

• Procure adapter plates, spacer rings, aluminum plates, battery boxes, coupler; get quotes and order. • Brackets: determine dimensions and have them made individually or in a package by a locksmith. • Junction box: Order a standard box or have it custom-made. • Have the HV cable made by a specialist electrician. • Make or buy BMS cable.

• Dismantle Leaf powertrain and traction battery. • Prepare modules for installation in boxes 2 and 3. • Insert battery box 1 empty and equip it with modules, install pre-charging and circuit breaker unit • Fit BMS and HV cables into battery box 2 and mount it with bracket. • Build charging cable and connect it to charging socket. • Guide charging cable, HV cable, BMS cable forward into engine compartment. • Connect e-motor and transmission to each other and install it in engine compartment (first, place rivet nuts in body to be later able to fasten battery box 3). • Mount inverter on e-motor. • Screw DC/DC converter and junction box on aluminum plate and place unit on CV. • Install empty battery box 3 and insert modules. • Put on cover of battery box 3 (fitted with BMS and HV cables). • Wire cables in junction box and put lid on junction box. • Put on charger. • Mount additional components. • Connect cables for each additional component. • Install cable box in front of the charger. • Install VCU (converted Fenix). • Install cooling circuit. • Install heating circuit. • Install frame reinforcement and impact protection. • Tests. • Mount splash and stone chip protection. • Test drives. • Approval.

Commissioning

So geht‘s / Batterieboxen

That‘s how it works Chapter 1

Battery boxes

1.1. Plan and build

1.2. Fitting in the modules

1.3. Brackets and mounting

That’s how it works – 1.1 Plan and build

Divide and distribute The battery pack of the Leaf donor vehicle consists of 24 modules. 12 of them are placed standing, 12 lying down – grouped into two units, each with six modules. In order to keep the transfer to the Volvo as simple as possible, we want to stick to this layout.

BOX 1

BOX 3 First, we have to check where battery boxes can be mounted at all. Certainly in the engine compartment, because the drive unit of an electric car requires less space than a combustion engine and its aggregates. This is good, but not good enough. So how about placing modules under the trunk and on the underbody? It turns out that battery boxes can be mounted there, too. The removal of the exhaust system left a gap in front of the rear axle, and the bulky tank that is now missing opens up space under the trunk. In fact, it is necessary to place battery boxes in three locations (Fig. 1) to accommodate all modules from the Leaf battery pack and (almost) keep their layout. This means: box 1 should hold 12 modules, boxes 2 and 3 six each.

BOX 2

For screwing box 1 to the side members of the vehicle frame, it must have a contact surface of 60 mm left and right. Since this area cannot be used over the entire length of the box due to the geometry of the vehicle, it has to be partially reduced (Fig. 3). Of course, we could have calculated the final contact surfaces and have the battery box manufactured according to those dimensions. However, we recommend reducing the contact surfaces and positioning the mounting holes on site. Boxes 2 and 3 are less complex than box 1. They each hold six modules, i.e. three sets of 2 modules. With inner dimensions of 720 × 350 × 170 mm, both have the same size and both have a lid, see Fig. 4.

Fig. 1: In order to distribute the 30 kWh capacity of the Leaf battery pack in the Volvo, three battery boxes are required.

In box 1 we not only need to house the 12-module unit which includes the battery management system (BMS, Nissan uses the term “Lithium Battery Controller”, LBC). In addition, there are the service-plug unit and the pre-charge unit. The latter is called Battery Junction Box, BJB, in Nissan terminology (Fig. 2). The space needed for these components results in the following inner dimensions of box 1: 890 mm wide, 565 mm long, 250 mm high (Fig. 3). All three dimensions are critical: • The width must fit the space between the two side members of the vehicle frame. • The length must end before the rear axle. • The height is important, because the distance between ground and lower edge of box 1 must not be smaller than before the conversion. Fig. 2: The contents of box 1: The 12-module unit with BMS, and in front of it the pre-charge unit (left) and the service plug unit.

Fig. 3: Battery box 1 – already with adapted contact surfaces, but still without holes.

Fig. 4: Battery boxes 2 and 3 are the same size.

That’s how it works – 1.1 Plan and build

Available Space Before we order the battery boxes, we need to check if we have measured correctly. Therefore, as the next step, we recommend making cardboard dummy boxes in the original size. Thanks to our dummy, it quickly becomes apparent that there is by far not enough space for box 1 after we removed the tank. In fact, we need to cut out a large part of the spare wheel well to harbor box 1. Figure 5 shows the spare wheel well and the tank behind it. After cutting out the spare wheel well (Fig. 6), the dummy box 1 fits perfectly! Also, after cutting off a few threads protruding from the underbody in front of the rear axle, dummy box 2 fits into the space previously occupied by the catalytic converter and exhaust pipe. Since boxes 2 and 3 are the same size, we were also able to use the dummy for the test in the engine compartment. There is also enough space (Fig. 7).

Ordering the boxes So far, paper and pencil have sufficed to sketch the boxes and make mock-ups with those dimensions. However, so-called DXF files are required so that the battery boxes can be manufactured from 3 mm thick aluminum efficiently and at acceptable costs. Companies that professionally process aluminum and other sheet metal with sophisticated machines work with this data format.

Philip is very familiar with the DXF format. He also has a good overview of the possible costs of producing these battery boxes and other metal parts. Based on the dimensions, he creates DXF files, requests and obtains offers – and then the order was placed without delay.

i CUTTING OUT THE SPARE WHEEL WELL • What’s needed: A powerful angle grinder and two to three grinding discs for metals (size preferably 180 mm). • Safety first: Angle grinders make much noise and sparks fly. So, we work with ear protection, safety goggles, safety shoes and gloves. Also, we covered everything that can be reached by the spark beam. Ideally, such work should be carried out not in the garage but in the open space.

Fig. 7: Box 3 fits into the engine compartment. For the test with the dummy box, we provisionally placed the electric motor and other components in their future locations.

Fig. 5: The bulky tank in the back creates space for box 1, but not enough. Most of the spare wheel well has to go, too.

Fig. 6: Not much left of the spare wheel well (viewed from the rear of the vehicle).

That’s how it works – 1.2 Fitting in the modules

TOOLS

It‘s almost like Christmas ... ... when the battery boxes are delivered. The shiny aluminum just looks cool. And the boxes fit perfectly! We are relieved, happy and a big step further. But the next tasks are already waiting.

How to attach the modules in the boxes? How to mount the pre-charge unit and the service-plug unit in box 1? Which cable inlets and outlets do we need? How to modify cell connectors in boxes 2 and 3 as one module changes its position?

Box 1: Fitting the 12-module unit in Box 1 fits into the designated opening we created in the trunk. But does the 12-module unit from the Leaf battery pack also fit in the box? To check this, we lift the unit with our motor crane and lower it for a test. And indeed: the unit is a few millimeters

too wide. Both the stabilizing rails and the ends of the four threaded rods that run horizontally through the modules and hold them together must be trimmed on the plus side of the 12-module unit (Fig. 8). After shortening the stabilizing rails, we drill new M10 holes so that the 12-module unit can be lifted again with the motor crane (Fig. 9).

Angle grinder Roller boards approx. 300 × 600 mm (for storing and easy movement of the module units) Drill Drill bits 6 mm, 10 mm, 12 mm The front stabilizing rail of the 12-module unit makes it easy to fix it to the bottom of the box. The rail has several M12 holes. We use four of them for attaching the unit. However, since the rail is placed 20 mm above the bottom of the box, we place two 250 mm long square irons (20 × 20 mm) from our stock below the stabilizing rail (Fig. 11).

Hole saws 16 mm, 20 mm, 32 mm) Motor crane Including chain and hooks

MATERIAL Box 1: Rear wall attachment Angle irons (4): 40 × 40/40 × 20 mm with M6 holes Hex screws: 4 x M6 x 20 mm

Attaching the 12-module unit in box 1 Although the 12-module unit weighs around 100 kilograms, it has to be screwed to box 1. We use four angle irons from our stock to fix it to the back wall (i.e. the wall facing the rear end of the Volvo). The angle irons are placed on the existing threads of the rear stabilizing rail of the 12-module unit and attached to the back wall of the box after we have marked and drilled the appropriate holes (Fig. 10).

Box 1: Bottom attachment Square irons (2): 20 × 20 mm, length approx. 250 mm, each with 2 M12 holes Hex screws: 4 × M12 × 45 mm Service plug unit: Attached via spacers on the bottom Hex screws: 8 × M6 × 30 mm (from the Leaf stock) Fig. 10: Using four standard angle irons from our stock, we mount the 12-module unit to the back wall of box 1.

Pre-charge unit: Attached via rubber buffers on the bottom Rubber buffers type B: 2 × 40 mm (height), 50 mm (width), with external and internal thread Hex screws: 2 × M10 × 35 mm, (incl. lock nuts) Cable inlets/outlets: Cable glands: 1 × 16 mm, 2 × 20 mm, 2 × 32 mm Battery control cable inlet (part of the connector flange of the Leaf traction battery box) Hex screws: 3 × M6 × 30 mm Boxes 2 and 3 (cover and retaining plates) Hex flange screws with shank (from the Leaf stock): 8 × M6 × 150 mm

Fig. 8: In order for the 12-module unit to fit into box 1, the four threaded rods that hold the modules together must be shortened by about one centimeter. The same procedure applies to the stabilizing rails.

Fig. 9: The stabilizing rails of the 12-module unit must be cut by about one centimeter (see black line, right), and new holes for lifting the unit must be drilled (see dots).

Fig. 11: The 12-module unit is not only screwed to the back wall of box 1 but also to the bottom.

Insulation All battery boxes must be lined with polypropylene sheets (e.g. Evacast PP film, 0.8 mm) in the signal color orange.

That’s how it works – 1.2 Fitting in the modules

Fastening pre-charge and service-plug units With the 12-module unit fitted in and attached to box 1, we can focus on the two remaining components that need to be attached: the pre-charge and the service-plug units. For easier access to these devices, and because we need space for incoming and outgoing cables, both components are not attached directly to the bottom of the box, but raised about four centimeters above that. With M6 screws from the Leaf we fasten the service-plug unit on two cable holders from the Leaf battery pack, which are no longer needed in their original role (Fig. 12). For mounting the pre-charge unit (Fig. 13 and 14) we use two rubber buffers (50 mm diameter, 40 mm height) with M10 thread and corresponding screws (length 35 mm).

Cable inlets and outlets

Fig. 12

Fig. 15: Cable entries on the front of battery box 1. For a more detailed version see p. 157.

Twelve battery modules, the BMS, the pre-charge unit and the service-plug unit make box 1 a central point in the vehicle‘s electrical system. This is reflected in six cable entries (Fig. 15). • A HV cable runs from the positive terminal of the 12-module unit via the pre-charge unit to the inverter in the engine compartment. • A second HV cable connects the negative terminal of the 12-module unit to the service plug, from where the HV cable goes to box 2. • Since the BMS is in box 1, the original BMS wiring harness (Fig. 16) from the Leaf battery pack must also be placed there. It connects to the battery control cable. • Finally, two BMS cables from box 2 and one from box 3 enter box 1.

When arranging the six cable entries on the front of box 1 (pointing towards the passenger compartment of the vehicle) we suggest starting from the center (Fig. 15). We can use cable glands for the two HV and three of the BMS connections. However, because of its plug-in mechanism, we need the original power-outlet unit from the Leaf battery pack for connecting the battery control cable (Fig. 17). With the angle grinder we separate the required piece so that we can attach it to the front wall of the box with three M6 screws. We recommend hole saws for drilling the remaining cable entries in the box wall (diameters between 16 and 32 mm).

Fig. 13 Fig. 16: The original BMS wiring harness from the Leaf battery pack is still used and connected as before – except for two control lines that are no longer required.

DO NOT COMPROMISE SAFETY

Fig. 14

Fig. 17: The original power-outlet unit (“connector flange” in Nissan terminology) from our donor vehicle: we need the right hand side to connect the battery control cable.

For the short distances from the 12-module unit to the pre-charge unit and the service-plug unit, we tried to reuse an HV cable from the Leaf battery pack. We cut two pieces of 32.5 cm each, stripped the insulation at the interfaces and crimped on cable lugs (35 mm2). So far so good. However, we had to realize that our pliers didn‘t really crimp cleanly. In our opinion, it is not possible to crimp cable with a diameter of 35 mm2 securely with a manual crimping tool. You just cannot be sure to exert the necessary pressure. For this reason, we had these cables – and all other HV cables as well – manufactured by our trusted electrician (p. 149).

That’s how it works – 1.2 Fitting in the modules

Boxes 2 and 3: Adapting cover and retaining plates In the LH and RH Front Stack of the Leaf battery pack there are four modules next to each other (2 × 2 modules + 2 × 1 module = 6 modules). However, our battery boxes only allow three modules next to each other (3 × 2 modules = 6 modules).

lifting the unit, the plates will bend. Therefore, before lifting, the gap between the split cover plates has to be filled with a piece of rubber or wood.

The modules are attached to the bottom of the Leaf battery pack via retaining plates. They contain the threads for the 150 mm long M6 flange screws with shank, with which the modules are fixed. This means: We also need these plates in our battery boxes.

As the 6-module unit fits in we can deal with attaching it in the box using the two M10 holes in the cover plates. On the box wall please mark two holes opposite the cover plate holes, take the modules out of the box and drill the two holes with a 11 mm metal drill bit.

But in order to fit properly, the edges and a module slot have to be cut at the top and bottom of the plate. A powerful angle grinder with a 180 mm blade is an advantage here, as there is quite a distance to be covered. Please also cut off the two threads that are welded to the plate, as they are not required and may get in the way (Fig. 18).

With screws that we have kept from dismantling the Leaf donor vehicle and spacers (height 20 mm, 10 mm hole; hard plastic), we can later – when we prepare boxes 2 and 3 for the final installation – attach the 6-module units of boxes 2 and 3 (Fig. 20).

As counterparts to the retaining plates, there are two more plates on top of the modules. These cover plates have four holes (diameter 10 mm) per module. One of the plates is used in its entirety, the second must be separated in the middle (Fig. 19).

Fig 18: The retaining plates for the modules need to be adjusted to fit in battery boxes 2 and 3. The picture shows the plate for box 2, which has to be shortened on the right. In addition, the upper and lower edges must be cut.

Fixing modules to cover and retaining plates With cover and retaining plates ready, we place the retaining plates on one of the roller boards, position the modules accordingly and put on the cover plates. Then we put the 150 mm flange screws through the holes and tighten them. However, four of these screws are missing per stack, because of the new arrangement of the modules. So we had to get eight of these screws.

Fig. 20: The modules in boxes 2 and 3 are screwed to the box via the openings in the cover plates.

Adapting and assembling cell connectors In boxes 2 and 3, we moved one module each. This means that we have to adapt the busbar arrangement in two ways: 1. The plastic insulation of the cell connectors must be severed between the individual modules lying next to each other. Then the cell connectors must be placed on top of each other.

Now that cover and retaining plates are fastened, the 6-module unit can be inserted into the battery box for a fitting test. The easiest way to do this is with the help of a friend. But as Udo was alone most of the time, one way to achieve this is to put the unit on a roller board. Then place the box almost on the same height and, with a little skill, let the unit slide into the box. Of course, as the 6-module unit weighs 64 kg it makes sense to lift it with the motor crane. But Udo had to be careful: Even if the retaining plates stabilize the modules, the plates are not strong enough to carry the entire weight of the unit. When

While we were able to transfer the 12-module unit from the Leaf to box 1 without any changes, this does not apply to the modules for boxes 2 and 3: one module changes its position. In case of box 2 one module moves from the bottom left – see the empty space on the retaining plate on the far left in Fig. 21 – one position further to the right. The position in box 2 is: top left; all other modules keep the position they already had in the Leaf; the same applies to box 3. There, a module moves one position to the left from the far right; the final position is then top right.

2. Two cell connectors have to be modified so that they fit to the new layout. Fig 19: One of the cover plates on top of the modules has to be split in the middle (the plate of the LH front stack can be seen in the picture, for battery box 2). We need the right side of the plate. In addition, the lower edge must be „flat“, i.e. the recess with the hole (in the picture below) must be cut on both panels.

Both tasks can be a bit tricky. That‘s why we set up a workspace on a desk so that we can work while seated and have good lighting. Be sure to have a carpet knife with a sharp blade, a 30 cm ruler and a steady hand for the procedure.

Fig. 21: Module migration by one position to the right, that is from bottom left to top left – still in the Leaf battery pack box. In this order the modules are put into box 2.

That’s how it works – 1.2 Fitting in the modules

Notes Attention: The protective cap for the positive pole in box 2 next to the cell connector is in the way to some extent. Therefore, the plastic insulation has to be trimmed by about one centimeter here as well.

After the two tasks regarding the cell connectors are finished, start fastening the cell connectors on the modules. Note: It is important to connect the white BMS cable in box 2 to the lower voltage sensor of the module on the top left.

Fig. 22

Fig. 25: The long cell connector in its new angled form. It used to be 50 cm long. It is connected with three size 4 round head Allen screws (length 9 mm) and nuts.

Fig. 23

Fig. 26: The cell connector with the plastic insulation cut to size as it is positioned on the modules.

Fig. 24

Fig. 27

Figure 22 shows the original structure of the cell connectors for the two individual modules in the LH Front Stack. The plastic bridge between the two modules has already been severed; Figure 23 shows the new position of the cell connector that was on the left before: it now sits above the other cell connector. To do this, plastic must be cut off at the lower cell connector. Otherwise the layout of the two cell connectors does not correspond to the distance between the lower and upper module. Plastic also needs to be cut back to allow the BMS cables to be rerouted cleanly.

Cell connector division Due to the shift in the position of one module in boxes 2 and 3, one of the cell connectors also has to be moved. The originally 50 cm long busbar (Fig. 24) is shortened and placed in two angles (Fig. 25). To do this, first carefully unclip the orange plastic insulation with a narrow screwdriver and remove the copper strip. Divide the copper strip into pieces of 21 cm, 9.5 cm and 9.5 cm length. Drill M6 holes at the ends of the sections, and screw them together as a test to check whether the pieces actually fit. Then divide the plastic insulation with the carpet knife. Ensure that all three sections each have a clip so that the front and back of the insulation can easily be re-attached to each other. Where the copper pieces overlap, cut off the edging of the plastic insulation. Then the front and back of the insulation will fit well together. This small-scale, sometimes tedious work is somewhat reminiscent of the model kit projects undertaken when we were young.

Bending work For the shorter second cell connector, be prepared to bend it, and it is a good idea to have vise for that. We need a classic bracket (Fig. 26) and can use the original cell connector for this. The new dimensions are quickly determined: contact surface for attachment 15 mm, height 18 to 20 mm, bracket length 83 mm. And here, too, cut and apply parts of the plastic insulation. When all clips are used up, just wrap it with orange tape. By the way: The short cell connector is mounted after the long cell connector. The reason is that the shorter connector needs to sit on top of the longer one. (Fig. 27).

That’s how it works – 1.3 Brackets and mounting

Secure fit Once the size and position of the battery boxes have been determined and we know how to place the modules in them, there is one final question: how do we attach the battery boxes to their respective locations? Box 1 This is comparatively simple in the case of box 1. Left and right it has 60 mm wide contact surfaces, which only have to be adapted to the available space (Fig. 28). On both sides we drill three holes (11 mm) through the frame from above (Fig. 29). Then we put the box back in and mark the positions of the holes in the contact surface of the box from below. The holes can be drilled just as quickly as screwed (Fig. 30 and 31). Later, we apply sealing compound along the lines where the box touches the body to prevent water entering the trunk or the rest of the spare wheel well. As an additional support for box 1 we mount a bracket made of flat iron (dimensions, p. 163). It encloses box 1 from below and is screwed to the frame using two existing threads (M10) (Fig. 30).

Fig. 28

TOOLS Drill Metal drill bits 8 mm, 10 mm Rivet nut pliers Motor crane including chain and hooks Hole saws 32 mm, 20 mm, 16 mm Jacks

Fig. 29

Fig. 31

MATERIAL

Fig. 30

Fastening Box 1: Hex screws 6 × M10 × 40 mm 2 × M10 × 40 mm Flat iron holder (4 mm) (dimensions, p. 163) Fastening box 2: Hex screws 1 × M8 × 40 mm for existing thread in body 1 × M10 × 40 mm for existing hole in body 2 × M8 × 35 mm for underbody Fastening Box 3: Rivet nuts 3 × M10 Flat iron (3 mm) 35 mm × 195 mm Angle iron (2 mm) 55 mm × 70 mm × 70 mm (2 pieces) Allen countersunk head screws 2 × M8 × 40 mm for box bottom 3 × M8 × 80 mm for box side wall Spacers (PVC) 3 × 10 to 30 mm for box side wall 2 × 10 mm for fixing module unit on box side wall Cable glands for boxes 2 and 3 32 mm, 20 mm, 16 mm

That’s how it works – 1.3 Brackets and mounting

Box 2 With box 2, we have to think, plan and measure a little more to create a bracket that meets the requirements. To attach it to the frame we can use an existing hole and thread on the left and right next to the rocker panels. However, these points are slightly offset from each other, and they are not at the same height. In addition, we need two more fasteners in the underbody in order to securely fix the box. And finally, we need to connect the box directly to the bracket. Otherwise there would always be some chafing, which must be avoided by all means. After bringing the empty box into its position in front of the rear axle and temporarily fix it there, for example with hard foam pieces, we determine the dimensions of the bracket. Ultimately, an asymmetrical construction is created (Fig. 32), which we ask our locksmith to manufacture. A few days later we pick up the bracket from our locksmith and we bring the box and bracket into their target position. Only then can we correctly mark the holes in the box for screwing it to the bracket. To do this, we place the empty box, including the lid, in the bracket and screw the unit to the frame using the existing hole and thread. In addition, we support the two flat iron arms on the rear of the bracket in order to be able to mark

the holes for attaching them to the underbody later. Next we separate the box and bracket again and drill four 11 mm holes in the box. Then we screw on the bracket (Fig. 33).

cables in particular require a certain amount of advance before they can be routed out of the box due to their limited degree of bending (Fig. 35).

box 2 goes to box 3). We connect them accordingly with disc spring nuts and also lead them out of the box through the lid, including cable glands.

It is necessary to improvise a bit with the two holes in the underbody. It is impossible to raise the vehicle high enough with normal jacks to work from below with a standard drilling machine. So, we use a mini cordless screwdriver to drill a 3 mm hole from below (the underbody is amazingly thin), which we then drill out to eight millimeters from the inside (Fig. 34).

Figure 35 also shows that the inside edge of the lid is lined with foam rubber to seal it. Taking a closer look, you will see two mis-drilled holes closed with rubber under the current outlets of the HV cables. We had forgotten that the cables must be routed over the rear axle (Fig. 36). This is only possible if the cable outlets are placed at the top and not at the bottom of the lid.

All in all, box 2 and its bracket weigh around 65 kilograms. To mount this unit, it would be an advantage to have two people and be able to lift the vehicle. Otherwise, it requires some skill to heave the box and bracket up and screw them to frame and underbody.

Once bracket and box are screwed together, the 6-module unit can be put into the box. To do this, we position the bulky box in such a way that the module unit can be inserted with the help of the motor crane. Before that, the orange plastic insulation needs to be placed. And before lifting the module unit, we clamp a piece of rubber between module space one and two/ three so that the retaining plate screwed onto the modules does not bend.

Udo had to do it alone and managed as follows in his garage (see following page).

Then we take our two BMS cables, which so far only have a connector in the direction of box 2, plug them in and guide the other end of the cables, including cable glands, through the holes in the lid. Proceed in a similar way with the HV cables (positive terminal of box 2 goes to box 1, negative terminal of

Now it‘s time to draw the cable inlets/outlets in the lid and drill them with hole saws: 2 × 32 mm for the HV cables, 1 × 20 mm for the 25 position cable and 1 × 16 mm for the four position cable. In doing so, we have to take into account that the HV

Flat steel bar: 6 mm Holes: 11 mm

205

180 40

130

180

Fig. 35

Fig. 34

Fig. 36

Fig. 33

210 200 15 40

200

730

Fig. 32: Bracket battery box 2.

130

That’s how it works – 1.3 Brackets and mounting

Mounting of box 2 • He raised the vehicle high enough to put it on stands in order to place box 2 and its bracket on a roller board and push it underneath. • Positioned one jack each under the left and right arm of the bracket and lifted the box step by step supporting the rear arms of the bracket against the underbody. • The box had to be lifted at a slight angle because this was the only way to lift the cables and cable glands protruding from the lid over the rear axle.

Fig. 37

Mounting of box 3

• When the box was fitted tight with the underbody, Udo attached the bracket on the left and right using the existing hole and thread. Also, he fixed it to the underbody using two M8 screws (from the Leaf fundus).

• We place the empty box on the flat and angle irons, insert the screws, but tighten them only loosely at first. • Then we attach the box to the body using the threaded rivets, and three Allen countersunk head screws M8 × 80 mm. To do this, we have to insert spacers between the box wall and the body, as the box does not lie flat against the frame. We use parts from our stock for this purpose.

Box 3 Box 3 can be fastened using a flat iron fixed to an existing hole close to the firewall; in the front two angle irons are put together and fixed onto the frame (Fig. 38). When taking measures, we had to be careful to place box 3 not too close to the firewall (Fig. 37). Otherwise we would not have been able to lower the module unit with the motor crane as the hood can only be opened so much.

Fig. 40

Fig. 38

Once the box is fastened, the bottom and inner walls must be insulated with orange plastic panels (Fig. 41). Then the module unit is lifted with the motor crane and lowered into the box. Before that, we need to check whether the hooks on which the module unit is hung can be removed after the

modules have been lowered as there is very little space between the box wall and the hook. Finally, fix the module unit to the box wall with two M10 screws and spacers (see p. 51, Fig. 20). Then only the lid of box 3 is missing. We need inlets/outlets for the HV cable from box 2, the HV cable to the inverter and for the BMS cable from box 1. When deciding on the position of the respective holes in the lid, we have to keep in mind again that the two HV cables cannot be routed straight up from the positive and negative terminal due to the limited degree of bending (Fig. 42).

To attach box 3 to the flat and angle iron, two 9 mm holes need to be drilled in the bottom of the box. The holes need to be countersunk for two Allen countersunk head screws (M8 × 40 mm) (Fig. 39). Additionally, box 3 needs to be fixed to the body. To achieve this we drill three 9 mm holes in the left side wall of box 3 and three corresponding 10 mm holes in the body (dimensions, (p. 161). We use the rivet nut pliers to press three M10 threaded rivets into the holes in the body (Fig. 40). To do this, the engine compartment should be completely empty, because riveting with conventional pliers requires a lot of space in order to be able to exert the necessary pressure. Fig. 39

Fig. 41

Fig. 42

So geht‘s / Antriebseinheit

That’s how it works Chapter 2

Traction unit

2.1 New mounting for the drive shaft

2.2 Coupling and mounting the traction unit

2.3 Inverter board swap

2.4 DC/DC converter, junction box and charger

This is how it works –2.1 New mounting for the drive shaft

New fix for the drive shaft bracket As long as the Volvo was an ICE car, the internal combustion engine has served as the anchor point for the drive shaft. Since the combustion engine is now missing, we need a new solution.

Fig. 2: Combustion engine and transmission after removal. The bracket for the drive shaft can be seen at the bottom right.

For pragmatic reasons (because it was less complex), the car workshop initially removed the combustion engine and transmission as a unit. Only then was the transmission disconnected from the engine and reinstalled, including the drive shaft section on the driver‘s side. On the passenger side, the drive shaft consists of the section that leads to the wheel, a joint with a boot and a free-wheeling ring (Fig. 1). On our Volvo 850, this section of the drive shaft was attached to the rear of the engine (Fig. 2).

On the left, we fix the new drive shaft mounting at the original Volvo engine bracket with an M10 screw (70 mm). On the right, it is screwed to the electric motor with an original Leaf screw (M12 × 160 mm) (Fig. 5).

TOOL Socket wrench 12 mm, 13 mm, 14 mm, 17 mm, 19 mm

This means: As previously the drive shaft is rubber mounted – on the one hand via the Volvo engine mount, on the other hand via the electric motor. Note: The dimensions of the drive shaft bracket cannot be transferred one-to-one to another Volvo 850 project or even to the first generation of the V70.

Of course, we kept the two-piece clamp that encloses the free-running ring on the drive shaft. Since the combustion engine is now missing, we need an idea on how and where to attach the bracket. The solution: a flat-bar construction that is screwed to both the electric motor and to the original Volvo 850 engine mount.

Drill Metall drill bits 8 mm, 10 mm

Fig. 3

Hex screws For clamp: 1 × M8 × 30 mm, 2 × M10 × 35 mm Volvo engine mount left 1 × M10 × 70 mm

From mock-up to solution We put together a bracket from various remnant pieces of flat iron (40 mm wide, 4 mm thick), screw it with the clamp and mark the contact points with chalk (Fig. 3). Then we have the piece welded, impregnated, painted black and finally screwed with the clamp (Fig. 4).

MATERIALS Volvo drive shaft clamp Two-piece unit, with screws, part number 914 3465

In order to determine the dimensions of this flat iron bracket (dimensions, p. 163), we first ensure that the drive shaft is correctly positioned and fixed in the wheel. The shaft must also be level. To do this, we support the joint on the frame accordingly.

We need one M8 screw (30 mm) in the upper hole, and two M10 screws (35 mm) in the other two holes below.

Fig. 5

Electric motor 1 × M12 × 160 mm (from the Leaf) Flat bar iron (remnant pieces) 40 mm wide, 4 mm thick Fig. 1: The drive shaft on the passenger side. The arrow indicates the free wheeling ring.

Fig. 4

Chalk

That‘s how it works – 2.2 Coupling and mounting the traction unit

TOOLS

Precision work

Socket wrenches 16 mm, 17 mm Allen key 6 mm

Whoever converts an ICE car to an electric vehicle needs many skills. The most mechanically demanding part is probably connecting the electric traction motor to the existing manual gearbox. This unit forms the new heart chamber of the vehicle.

Jigsaw For sawing out the plywood panel Drill Wood drill bit 10 mm, countersink drill bit Hole saw 20 mm (for hub hole)

E-Motor

When we talk about coupling traction motor and gearbox, two sets of topics are meant – on the one hand, the joining of the two components with the help of adapter plates and spacer rings. On the other hand, the actual connection of the two hubs via the hub coupler (Fig. 6).

Adapter plate

MATERIAL Rotex GS38 coupler

Let‘s start with the adapter plates and spacer rings. We recommend aluminum with a thickness of eight millimeters, as this material thickness is robust enough on the one hand and can still be lasered precisely on the other. If the aluminum were thicker, precision would decrease, and precision is very important with these parts.

Clutch disc from the Volvo (we need the hub cap)

Spacer rings

Hub cap from the Leaf gearbox Traction motor adapter plate Aluminum, 8 mm

Coupler

Gearbox adapter plate Aluminum, 8 mm

The topic of lasers is already an indication that we are dependent on the support of external experts for the work in this chapter. Because even a technically skilled and above-average well-equipped car enthusiast is likely to be overwhelmed here. The reason: Lathes and computer-controlled machines are required to manufacture the adapter plates, spacer rings and later also the hub coupling.

Adapter plate

Spacer rings Aluminum, 8 mm, outer dimensions 220 mm, inner dimensions 150 mm Gearbox

Highly sophisticated machinery needs data so it knows what to do. Philip has taken over the processing of this data. Based on his previous knowledge and experience from his own projects, he created the production data for the adapter plates and spacer rings.

Socket head countersunk crews with shank: • 6 × M10 × 75 mm for attaching the adapter plate to the traction motor (Leaf screws) • 4 × M10 × 80 mm for connecting traction motor/adapter plate, gearbox adapter plate and spacer rings • 14 × M10 × 40-60 mm for attaching adapter plate to gearbox Hex screws: 14 × M10 × 40-60 mm for attaching adapter plate to gearbox

Fig. 6

Plywood panel 5 mm, 500 × 500 mm

That‘s how it works – 2.2 Coupling and mounting the traction unit

Electric motor adapter plate The gearbox adapter plate In order to be able to generate the required production data for the adapter plate, precisely worked patterns are required, for example made of plywood. How we made the pattern for the gearbox adapter plate (Fig. 7) can be outlined in six steps. 1. Place the removed gearbox with the flat side on a sheet of tracing paper and fix it. 2. Trace the outline of the gearbox and the through-holes onto the tracing paper. 3. Cut out the tracing paper (outline and holes). 4. Fix the paper on the gearbox, mark the holes that are still missing and the position of the hub. 5. Attach paper to a plywood panel and transfer outline, drill holes and hub position.

The plywood pattern forms the blueprint for making the aluminum adapter plate. Therefore, please check whether the pattern really fits perfectly on the gearbox. By the way: The Volvo gearbox has 14 mounting holes. Our recommendation is to use all of these holes so that the gearbox and its adapter plate are „bombproof“ together.

The production of the traction motor adapter plate basically repeats the process that we described for the gearbox adapter plate. In our Volvo conversion, however, we were able to eliminate these steps because we could use data that Philip had already collected during his own conversion with Leaf components to manufacture the plate. The electric motor adapter plate is attached to the motor in six places (Fig. 9). For this we use the screws from the Leaf donor

vehicle (M10 × 75 mm). And of course this plate also contains four holes for screwing the spacer rings and the gearbox adapter plate. These screws are countersunk socket screws (M10 × 80 mm, with 6 spacer rings). Countersunk because these screws have to be flush with the side of the plate that faces the electric motor. Otherwise the plate cannot be attached. So we have to countersink the four holes in the electric motor adapter plate accordingly (Fig. 10).

However, one important job is still to be done: the gearbox adapter plate requires four additional holes for connecting it to the electric motor plate and the spacer rings. These holes must be placed in such a way that the hubs of the electric motor and gearbox can be coupled in a balanced manner. In order to be able to determine the position of the holes, the gearbox must be installed in its original position. Then, with the help of a spirit level, the plumb line is guided exactly through the middle of the gear hub (Fig. 8). On this basis, Philip was able to determine the position of the holes in conjunction with the data from the adapter plate for the electric motor.

6. Saw out the plywood panel and drill holes.

Fig. 8: Gear with spirit level and plumb line.

Fig. 7: Our pattern for manufacturing the gearbox adapter plate – a plywood panel.

Fig. 9: Electric traction motor with adapter plate screwed on and screws for fastening spacer rings and gearbox adapter plate.

Fig. 10: Countersink the holes for screwing the adapter plates and spacer rings.

That‘s how it works – 2.2 Coupling and mounting the traction unit

Unit made of adapter plates and spacer rings As soon as the adapter plates for the electric motor and gearbox as well as the spacer rings and screws are ready, we can try screwing the unit together (Fig. 11 and 12). The number of spacer rings required between the adapter plates can be determined as follows:

And another tip: Insert the screws for attaching the electric motor plate to the motor before the transmission adapter plate is placed on the spacer rings and screwed. Because afterwards there is not enough space to insert the screws if six spacer rings are used (as with the Volvo).

1. Assemble the coupler (two metal parts with a red rubber buffer between the halves) 2. Push the coupler onto the gearbox hub as far as it will go. 3. Temporarily position the electric motor opposite the gearbox in the engine compartment. Insert the hub of the electric motor into the coupler – also up to the stop. This dimension is the minimum dimension that must be bridged with the adapter plates and spacer rings. We installed six rings on our Volvo 850, so that the unit consisting of adapter plates and spacer rings has an external dimension of 64 mm (6 spacer rings of 8 mm each plus 2 adapter plates of 8 mm each). Fig. 11: The unit consisting of adapter plates and spacer rings viewed from the electric motor side. Fig. 13: The hub coupler consists of three parts: the hub attachments for the electric motor and gearbox and a red rubber buffer.

Hub Coupler Now for the hub coupler. It is the most critical mechanical component in a conversion project. Because a reliably working coupling between the electric motor and the transmission can only be created if both are precisely aligned with each other. This means: The output hub of the electric motor must be connected horizontally, vertically and axially centered with the input hub of the gearbox. This is essential to avoid damage to the bearings of the gearbox and motor.

The use of other supposedly suitable attachments is strongly discouraged. Because even if the number of teeth is the same and it seems like it will fit – it doesn‘t. Hub profiles and parameters are model-specific. If other attachments are used, sooner or later this will lead to the failure of the coupler.

The hub coupler is made from a Rotex GS 38 industrial claw clutch. The mechanical clutch in the Volvo is no longer necessary. Both halves of the Rotex GS 38 are machined on a lathe so that they each taper towards the motor and gearbox (Fig. 13). A (red) rubber buffer is later inserted between the two halves (Fig. 14). It is crucial for a precisely fitting and therefore reliably working hub coupler to use the original hub attachments on both the transmission and motor side. They are welded into the Rotex GS 38. Fig. 12: Side view of the unit consisting of adapter plates and spacer rings: the electric motor side on the left, the gearbox side on the right.

Fig. 14: The components of the hub coupler.

That‘s how it works – 2.2 Coupling and mounting the traction unit

Hub coupler on the transmission side

Double wedding

For the transmission side this means: The hub attachment in the Volvo clutch disc (Fig. 15) needs to be removed and welded into an adapter sleeve, since the opening of the Rotex GS 38 is larger than the circumference of the hub attachment. The adapter sleeve is also made on the lathe.

Automobile manufacturers speak of a “wedding” when the chassis, engine and transmission are combined with the body. We‘re even having a kind of double wedding. First, were more than happy when we succeeded in coupling the electric motor and the transmission. Secondly, the mounting of the traction unit in the Volvo is another good reason to celebrate.

Finally, a stop is welded onto the Rotex GS 38 on the gearbox side. This prevents the hub coupler from slipping (Fig. 16). This half of the hub coupler will later be slid onto the hub of the gearbox. Before doing this, please remember to unscrew the copper shaft in the gearbox (Fig. 17) – otherwise the adapter will rub against it, which would also lead to system failure.

Wedding 1: Electric motor and transmission We recommend the following procedure when assembling the electric motor and gearbox. You should always be two people: 1. Screw the unit consisting of adapter plates and spacer rings to the electric motor. Fig. 16: Hub coupler stop on the transmission side.

2. Place the gearbox on a workbench, for example, with the opening facing upwards. 3. Put the hub coupler on the gearbox hub. 4. Place the electric motor on the gearbox from above. Carefully insert the electric motor hub into the hub coupler on the gearbox. 5. Now the electric motor and transmission sit exactly on top of each other (Fig. 19).

Fig. 15: Volvo clutch disc: The hub attachment in the middle is important.

Fig. 17: Copper shaft in gearbox.

6. In this position, check whether the holes in the gearbox adapter plate and the fastening holes in the gearbox actually match. This means that the screws must be able to be inserted into the holes without the position of the electric motor and transmission changing even a fraction of a millimeter.

Fig. 19: Transmission and electric motor in an unusual position. The advantage: Both components can be precisely connected to each other.

7. If this is not possible for every screw, individual holes must be reworked. That‘s not a problem as long as it‘s minor extensions for two or three holes.

Hub coupler on the electric motor side No stop is required on the electric motor side. But we need the original hub attachment from the gearbox of the Leaf donor vehicle (Fig. 18). This hub attachment must be welded into the other half of the Rotex GS 38. An adapter sleeve will also be necessary here. So much for the description of the process. Our recommen dation: Leave the manufacture of the hub coupler to an expert who has experience with it. In our Volvo conversion, Philip took on this task together with a metal construction company (p. 149). Fig. 18: Hub attachment from the Leaf gearbox.

That‘s how it works – 2.2 Coupling and mounting the traction unit

Wedding 2: Placing the traction unit in the engine compartment Before the traction unit can be lifted into the engine compartment, some preparations have to be made. First we install two flat irons with rubber buffers on which the traction motor will rest (Fig. 20 and 21). The irons are attached to the front and rear of the axle carrier taking advantage of some existing holes. In the rear we use M10 × 35 mm hex screws, in the front M10 × 125 mm hex screws with shank. That doesn‘t sound particularly complicated. However, things are made somewhat difficult by the fact that the underside of

the traction motor is not even. The height of the buffers must therefore be adjusted so that the motor is actually level and can be fixed. In our case, the rubber buffers had a height of about 10 mm (left flat bar at the front and back) and 20 mm (right flat bar at the front) or 25 mm (right flat bar at the back). Of course, at this stage of the project, such work is impractical. Starting from the original position of the gearbox, we have therefore previously temporarily installed and balanced the traction motor (Fig. 22 and 23). This is also necessary in order to be able to determine the dimensions for the holders that we also need.

Fig. 20: The electric motor sits on two flat irons with rubber buffers.

Fig. 22: The electric motor must be balanced...

Fig. 21: To carry the weight of the traction motor the flat irons should be four millimeters thick (dimensions, p. 165).

Fig. 23: ... like the gearbox.

Back to the preparations for installing the traction unit: What we also need to create is a pad on the garage floor (e.g. made of hard foam) to stabilize the gearbox when we drop the unit. The gearbox is secured with its two original mounts and rests on the right side on a rubber stopper on the frame. At the position of a former engine mount we attach an angle iron on a rubber buffer (Fig. 24). This should suffice to ensure the firmness of the transmission.

Fig. 24: The gearbox is attached to the frame at the front not only via a new original Volvo torque arm (below), but also via an angle iron on a rubber buffer.

That‘s how it works – 2.2 Coupling and mounting the traction unit

MATERIAL SCREWS FROM VOLVO AND LEAF The motor mounts In contrast to the gearbox for which we can use existing mounts, more work is required for the traction motor. Towards the firewall, we fix the traction motor to the steering rack using a special construction consisting of Volvo and Mitsubishi mounts as well as pipe clamps and hex screws (Fig. 25). The Mitsubishi mount (RU-504) is screwed into an M8 thread in the traction motor. With the Volvo mount (part number 944 5853) we overcome the distance to the steering rack, to which the construction is screwed using the pipe clamps (Fig. 26).

the left side of the traction motor by three screws as well as to an angle iron with two more screws (Fig. 27). The angle iron sits on a rubber buffer (type B, height 30 mm) and is screwed from below through an existing hole in the frame (Fig. 28). When all holders are in place, the mounting of the traction unit looks like this – viewed from the left and from the right (Fig. 29 and 30):

Lower engine mount: 2 × flat iron 4 mm (dimensions, p. 165) 2 × M10 × 35 mm hex scrtews (rear) 2 × M10 × 125 mm hex screws (front) 4 × rubber buffers, type D, M10 male thread, 50mm diameter, 30 mm height, lock nuts, washers

Front motor mount: Mount (dimensions, p. 155), screwed with Leaf E motor screws Angle (dimensions, p. 156) Rubber buffer, type B, external thread M10, 50 mm diameter, 50 mm height Hexagon screw with shank M10 × 140 mm

Rear motor mount: 2 × motor mounts Volvo (part number: 944 5853) 2 × 2 pipe clamps (DIN 3567 A), 1.5 inch 2 × motor mount RU-504 (from Mitsubishi) 2 × hex screws with shank M10 × 140 mm

Front gearbox bracket: Angle (dimensions, p. 157) 1 × type B rubber buffer, external/internal thread M10, 50 mm diameter, 50 mm height

On the left we connect the traction motor to the axle carrier via the drive shaft holder. In addition, we need a firm connection to the front. We achieve this with a holder that is fastened to

i WHAT ABOUT AUTOMATIC TRANSMISSION?

Fig. 27: Holder for fastening the traction motor to the front of the axle carrier (dimensions, p.166)

Fig. 29: The traction motor with mountings below, rear, front and side (via the drive shaft bracket). Fig. 25: Attaching the traction motor to the steering rack, partly with used, partly with new components.

Fig. 26: Fastening the traction motor to the steering rack.

Fig. 28: Rubber buffer, type B, fastened from below with an M10 hex screw (140 mm); the piece of metal under the washer is necessary in order to use the existing hole (diameter 25 mm).

So far, almost exclusively vehicles with manual transmissions have been converted to electric. However, in large car markets such as the USA, automatic transmissions dominate. So, solutions are also needed for this. And there is. The hybrid transmission from the Lexus GS450 is suitable for rear-wheel drive, for example, and the motor-transmission unit from the Toyota Prius is suitable for front-wheel drive. In both cases, of course, the previous automatic transmission must be removed. All in all, the conversion of an automatic vehicle is just as complex as that of a manual one. Although no adapter plates, spacer rings and couplers are required, the drive shafts have to be custom made. There are specialized companies that can do this for you. More information on the conversion of vehicles with automatic transmissions using the example of an Audi A2 on Johannes‘ YouTube channel: https://www.youtube.com/watch?v=2tZAd6tv0L4

Fig. 30: The gearbox is attached with original holders – as well as with an additional angle in front; see also the two flat irons (left) carrying the traction motor.

That‘s how it works – 2.3 Inverter board swap

TOOLS

Current transformer

Wrench 10 mm Screwdrivers Phillips and slotted

The electric motor and gearbox form the new heart of the electric Volvo 850. However, additional components are required for the heart to be able to beat reliably.

Unsoldering pump Soldering iron

A central port of communication in an electric car is the inverter of the electric motor. This inverter converts the direct current from the traction battery into alternating current for the electric motor and regulates its speed. The inverter from the Leaf can only fulfill this task in the Volvo, if we can modify it to communicate with the Volvo’s VCU. For this, we need to replace the original control board in the inverter (Fig. 29) with a fully equipped board from Johannes.1

Opening the inverter

Removing the original board

When removing the drive unit from the Leaf donor vehicle, we have already separated the charger, inverter and traction motor from each other. We now take the inverter, turn it over and place it upside down so that the protruding copper contacts are not damaged (Fig. 30).

Now, we pull off the connectors on the upper edge of the circuit board (Fig. 32) and remove the screws with which the circuit board is fixed with a Phillips screwdriver. But we have to be careful and use a perfectly fitting screwdriver because bolt adhesive was applied to the screws. This creates the danger of twisting them off if weapply too much force too quickly.

We loosen the twelve screws in turn. Be careful, the cover is glued to the body of the inverter. Before it can be detached, please place a screwdriver in the indentations (Fig. 31) and lever the cover at several points until it detaches.

MATERIAL Solder Bolt adhesive Screws (from the Leaf) 12 × M8 × 30 mm For fastening the inverter to the electric motor 3 × M8 × 20 mm (black) For the copper rail connection between the inverter and the electric motor 2 × M6 × 20 mm For the cover plate

i VIDEO

Fig. 30

If you want to watch the board swap process “live”: Johannes has created a video on his YouTube channel: Lab Update #20: Leaf Controller Swap. https://www.youtube.com/watch?v=T_6hw6vGzfM& feature=youtube

Fig. 29: The opened Leaf inverter with a view of the control board. Fig. 31

Fig. 32

1Please note: In the meantime a solution has been developed that does not require the control board swap.

That‘s how it works – 2.3 Inverter board swap

Notes The tricky part The original board will be replaced, but we definitely need the original board connector as it is not available on the market (Fig. 33). That means the connector has to be detached (desoldered) from the circuit board and soldered to Johannes‘ circuit board. It is best to use a desoldering pump for this, and use electro solder with a maximum diameter of 1.0 mm for soldering. Otherwise it will be difficult to cleanly solder the pins of the connector without them contacting each other. Figure 34 shows Johannes‘ board with the connector from the original board. When that‘s done, we simply reattach the connectors and screw the circuit board to the bracket. We use some bolt adhesive and are careful not to overtighten when fastening. Finally, we put the cover on and screw it tight.

Fig. 33

That’s all. The circuit board swap in the Leaf inverter is complete.

Fixing the inverter on the electric motor Having prepared the inverter for use in the Volvo, we can put it back in its original place: on top of the electric motor. When putting it on, we make sure that the copper rails are inserted cleanly into the opening (Fig. 35). Then we fasten the copper rails to the contacts with the three black M8 screws and screw on the cover (Fig. 36). Now, all that is left to do is toput in and tighten the M8 screws that connect the inverter and electric motor to each other.

Fig. 35

Fig. 34

Fig. 36

That‘s how it works – 2.4 DC/DC converter, junction box and charger

Tower construction Electric motor and gearbox are connected. We have made the Leaf inverter fit for use in the Volvo by replacing the control board and have already screwed it to the electric motor. But assembling the drive unit has not been finished.

TOOLS Wrench 10 mm, 13 mm Allen key 5 mm Countersink

While the electric motor and gearbox form the ground floor of the drive unit, the first floor belongs to the inverter. The DC/DC converter and junction box (J/B) reside on the second floor. Both components are mounted on an aluminum plate, which in turn is connected to the inverter (Fig. 37). Since the surface of the inverter is not flat, we need three spacers (height 10 mm) on the left side to attach the aluminum plate, and on the right we place a small spacer plate in between inverter and plate. We use five round head socket head screws (M8 × 60 mm). The charger sits enthroned above the DC/DC converter and J/B (Fig. 38). It is screwed to the aluminum plate at the rear left and front right which will take place at a later point in the course of the project. However, we have to keep in mind that before the charger is put on, the connectors should all be put in to the back of the DC/DC converter – i.e. the 12 volt and ground cable, the CAN Bus and enable cable (black connector) and the J/B connector (blue connector). In addition, of course, the J/B must also be fully equipped with everything that goes in there. Because once the charger is on top, the J/B and the back of the DC/DC converter can no longer be reached. With a total of 27 holes, our aluminum plate needs not fear comparison with Swiss Emmental cheese (Fig. 39 on the following page). The dimensions of the plate, the opening for the inverter copper contacts and the holes for fixing the plate to the inverter are saved in a DXF file created by Philip. It forms the basis for the manufacture of the plate in a metal processing shop. We inserted the remaining holes after their respective positions had been defined.

Hole saws 16 mm, 20 mm, 32 mm

MATERIAL DC/DC converter Screws: 8 × M6 × 35 mm (countersunk hexagon socket) 1 × M8 × 35 mm (hexagon) for ground connection

Fig. 37: DC/DC converter (left) and junction box sit on an aluminum plate that is bolted to the inverter (see arrows and number 1 on the following page).

Junction box: Rubber buffer type B: 4 × M6, height 20 mm, diameter 25 mm 2 × M8, height 20 mm, diameter 30 mm Screws (countersunk hexagon socket): 4 × M6 × 20 mm, 2 × M8 × 20 mm Aluminum plate on inverter: Screws: 5 × M8 × 60 mm (round head hexagon socket) Spacer: 3 × height 10 mm, width 20 mm, bore 8 mm Charger to support plate Screws (countersunk hexagon socket): 1 × M8 × 120 mm (rear left), 1 × M10 × 120 mm (front right) Gaspoti: Hex screw: 1 × M8 × 25 mm Cable clamp (middle right) Hex screw: 1 × M6 × 25 mm

Fig. 38: The charger (temporarily attached) sits on top of the drive unit.

That‘s how it works – 2.4 DC/DC converter, junction box and charger

Inverter, 9 mm (hole), 5 × M8 (screw) Ground connection DC/DC converter, 9 mm, 1 × M8 Charger, 9 mm and 11 mm, 1 × M8, 1 × M10 Junction box, 2 × via inverter, right hand side Cable clamp, 7 mm, 1 × M6

Throttle pot, 9 mm, 1 × M8 Charger ground connection, 9 mm, 1 × M8 Junction box on aluminum plate, 7 mm, 4 × M6, 9 mm, 2 × M8 (rubber buffer fuses) DC/DC converter on aluminum plate, 7 mm, 8 × M6

Positioning pins from inverter, 11 mm, 2 holes

Fig. 39: With a total of 27 holes our plate looks like Swiss cheese.

That‘s how it works – 2.4 DC/DC converter, junction box and charger Junction box Luckily we can use a standard size (175 × 275 × 65 mm) so the box is quick and cheap to get. But there is still a lot to be done before it can actually be used. In addition to the holes in the bottom of the box, you need to make the openings for the following connections

Preparatory work Before the large aluminum support plate can actually be put on, further preparatory work is required – beyond the holes:

• HV cable from box 1 to positive pole inverter • DC/DC cable to positive and negative pole WR • HV cable from box 3 to negative pole WR • charging cable to plus – and negative pole WR • HV heating on positive and negative pole WR

• Place the small spacer plate over the inverter connections and insert the orange rubber ring (Fig. 40). Otherwise the large carrier plate wobbles. • Countersink the screw holes for the DC/DC converter on the underside of the aluminum plate (Fig. 41) so that the countersunk screws are flush with the plate. Then screw on the DC/DC converter. • Prepare the junction box (see following page) and also fix it to the plate from below using the rubber buffers (Fig. 42). The rubber buffers serve as carriers for fuses (40 A charger, 30 A DC/DC converter, 225 A HV cable). That means: The J/B must be ready and mounted on the carrier plate. That also means: The cable entries have to be drilled and the box has to be lined with orange plastic.

The diameters of the cable entries are 16 mm, 20 mm and 32 mm. It is therefore advisable to work with hole saws (Fig. 44). The openings can thus be produced without any problems.

Fig. 41

This completes the preparation of the support plate which will be mounted on the inverter. As mentioned, the charger will be attached after the junction box has been wired. Here is an overview of the holes in the housing of the junction box (Fig. 45):

Fig. 44

DC/DC converter (diameter 16 mm)

HV cable from Box 1 (32 mm)

• Finally, on the back left of the plate, an M8 × 25 mm screw for the ground connection of the DC/DC converter and an M8 × 120 mm long countersunk screw with shaft to later attach the charger must be inserted and fixed with an adhesive strip (Fig. 43).

Fig. 42

HV cable from Box 3 (32 mm) Fig. 40

Fig. 43

Charging cable (20mm) HV heater (20mm)

So geht‘s / Zusatzkomponenten

That‘s how it works – Chapter 3

Additional components 3.1 Gas potentiometer, hydraulic pump, vacuum pump 88

3.2 Acoustic warning signal, HV heating, mini cooler

3.3 Cooling circuit, heating circuit

That‘s how it works – 3.1 Gas potentiometer, hydraulic pump, vacuum pump

Comparatively simple Battery boxes and the drive unit were a real challenge in terms of planning and implementation. In contrast, the assembly of the additional components is comparatively simple. All we have to do is to adapt a few parts and work on some holders.

Fig. 1: The original throttle cable holder from the Volvo, already with our electric gaspoti screwed on. The holder is flexed at the marked points. We drilled the extra hole at the top left.

Well, for this we need the electric gaspoti, which we bought used. Depending on how hard we step on the gas pedal, it sends electrical signals to the VCU, which in turn tells the electric motor, based on corresponding characteristic curves, how much power it should produce. So this is a question of the software and therefore part of the VCU control board that Johannes designed. As we have the gaspoti under electric control we just have to mount it firmly in the vehicle – in a position that does not affect the previous course of the throttle cable. Fortunately, this is possible on the right side of our aluminum carrier plate. To attach the gaspoti, we can use the original holder for the throttle cable from the Volvo (Fig. 1). However, we have to flex off part of it and drill an extra hole.

When our Volvo was still a combustion vehicle, the oil pump for the power steering was set in motion by the drive belt on the engine. That means: We need an electric alternative for the belt, too. We go for a used TRW hydraulic pump. The product was installed in large-volume models and is therefore readily available – and it has already proven itself many times in other conversion projects. The position of the electric hydraulic pump is determined by the fact that we need to continue using the tubes from the Volvo. We are able to do this because we can mount the pump on the front axle carrier.

Gaspoti Let‘s start with the so-called gas pedal value sensor or potentiometer (gaspoti). In a combustion vehicle, the gas pedal regulates the fuel supply and thus the power of the engine. In our Volvo, the gas pedal was connected to the throttle valve via the gas cable. To put it simply, together with the injection pump, it ensured the right air-fuel mixture to accelerate the vehicle to the desired extent. But without a combustion engine, there is no throttle valve and no injection pump. So how does the gas pedal work now?

Hydraulic pump

It pays off that we buy used components with the original brackets whenever possible. Though the original holder (Fig. 4) has to be adapted somewhat, it fits on the axle carrier. Also, we need to cut a small angle (Fig. 5, dimensions, p. 169) out of a former Leaf bracket to bolt the pump to the axle carrier both top to bottom and front to back.

Fig. 5: The auxiliary bracket that provides a connection between vertical and horizontal screw connection.

After we have drilled two holes (11 mm) through the axle carrier, we use two countersunk hexagon screws with shank (M10 × 120 mm) for fastening. However, we shorten the screw that runs through the axle carrier from top to bottom by ten millimeters. That way, it closes flush with the nut and we avoid protruding threads on the underbody (Fig. 6). Finally, we have to insert the pump (Fig. 7).

Fig. 6: The original holder mounted on the axle carrier... Fig. 2: The gaspoti with holder is welded to the edge of a flat iron which in turn is screwed to the aluminum carrier plate.

We have the adapted original holder welded to a flat iron (240 mm × 40 mm × 4 mm). Then the gaspoti is mounted with two screws (M6 × 50 mm) and spacers (Fig. 2). We fasten the unit consisting of the flat iron and gaspoti/holder with a screw (M8 × 30 mm) to the aluminum carrier plate via the hole provided. Now all we have to do is hook the throttle cable in and clamp it. To be on the safe side, we decided to clamp it twice (Fig. 3).

Fig. 3: The throttle cable construction with the throttle cable hooked in and secured.

Fig. 4: The adapted original bracket for the electric hydraulic pump is screwed vertically and horizontally to the axle carrier.

Fig. 7: ... and with the pump installed.

That‘s how it works – 3.1 Gas potentiometer, hydraulic pump, vacuum pump

MATERIAL

Three in one go

Gas potentiometer Volvo original throttle cable holder Flat iron: 240 mm × 40 mm × 4 mm (dimensions, p. 156) Hex screws: 2 × M6 × 50 mm, 1 × M8 × 30 mm Spacers: 2 × 30 mm long, diameter 9 mm, bore 7 mm

Enough of the individual assemblies. Now we take care of three components in one go – with the help of a carrier rail that we mount in front of the drive unit.

Vacuum pump As for the hydraulic pump, we also need a replacement for the previous vacuum pump in order to generate vacuum for the brake booster in the Volvo 850 electric. A wide range of used products is available for this application. We opt for an electric vacuum pump that is installed in models from the Volkswagen Group. If you have the choice, you should buy a product that also comes with hoses and possibly even with a valve and sensor (Fig. 8). The pump is attached near the brake booster behind the 12 V battery. To do this, we construct a holder that is lowered to the front on the right side (dimensions, p. 170). The forward slant allows us to use an existing hole in the body (we added a second one), and it also sits low enough to allow the hood to close. Our holder also contains holes to which we can screw the ignition relay and its ground connection (Fig. 9).

That‘s how it works – 3.2 Acoustic warning signal, HV heating, mini cooler

Clamp to secure throttle cable Hydraulic pump Holder (dimensions, p. 158) Screws: 2 × M10 × 120 mm countersunk hexagon socket with shank Vacuum pump Holder (dimensions, p. 160) Hex screws: 5 × M6 × 20 mm or 25 mm Carrier rail (for acoustic warning signal, HV heating, mini cooler) Aluminum L angle profile 50 mm × 50 mm × 3 mm (dimensions, p. 159)

The carrier rail fits perfectly where the mighty Volvo radiator used to be. Two threads (M10) left and right in the body also make it very easy to fix the rail. However, the statement “three in one go” is only partially true. Because for the HV heating and the mini cooler we first need holders. Otherwise, we won’t be able to attach these components to the carrier rail. The acoustic warning signal from the Leaf donor vehicle can be attached to the rail by way of its original bracket which we kept in wise foresight.

weld it. Four screws (M5 × 15 mm) are required to attach it to the heater. We use what we have in stock, i.e. Allen and Phillips screws. We use two hex screws (M8 × 30 mm) for mounting on the carrier rail. For the holder of our mini cooler (dimensions, p. 169) we rummaged through our metal parts crawler box and found what we were looking for: The cooler is attached to an angle, which in turn is connected to two rails. These rails are screwed to the carrier rail (Fig. 10).

Because of its geometry the HV heater requires a sophisticated bracket construction (dimensions, p. 168) and a locksmith to

Acoustic warning signal Hex screws: 2 × M8 × 25 mm HV heating Holder (dimensions, p. 157, 158) Screws: 4 × M5 × 15 mm, 2 x M8 x 30 mm

Fig. 8: Assembled vacuum pump with non-return valve (1), sensor (2) and tube to the brake booster (3).

Mini cooler Holder (dimensions, p. 159) Hex screws: 6 × M5 × 15 mm, 2 × M6 × 20 mm Cooling and heating circuit Reservoirs, joints, clamps

TOOLS Wrench 10 mm Fig. 9: We need a total of five hex screws from our Leaf fundus (M6 × 20 mm or 25 mm): Two for fastening to the frame (not visible), one for the pump (1), and one each for the relay (2) and its ground connection. (3).

Angle grinder Screwdriver

Fig. 10: Acoustic warning signal (left), HV heating (center) and mini cooler on the carrier rail (view from the front towards the engine compartment).

That‘s how it works – 3.3 Cooling circuit, heating circuit

Thermal management light The heat flows in an electric car have to be controlled even more than in a combustion engine vehicle. This is known as thermal management, and it plays a critical role in electric conversions. In our project, however, this is a manageable task.

The thermal management of a traction battery with the help of a liquid is now standard in new electric vehicles. However, Nissan only opened up to this topic with the ARIYA, which came onto the market in 2022. The Nissan Leaf did not have a liquid cooling system until the final model year which was 2022. So there was no active temperature management for the traction battery of our donor vehicle, which was built in 2016. This has not changed after the transfer to the Volvo. In view of the Central European climate, which is still moderate despite global warming, and Udo‘s driving profile, which is characterized by short journeys, we do not consider this to be a problem.

Installing the expansion tanks

Our thermal management is therefore not too challenging and mainly addresses two tasks:

For the cooling and heating circuits, we mainly use existing hoses and clamps from the Leaf, but also some components from the Volvo. However, additional clamps, a piece of new radiator hose (approx. 2 meters) as well as connectors, branches and tapers are also required (Fig. 16).

• Cooling the traction unit (electric motor, DC/DC converter, inverter) and the charger. • De-icing of the windows and heating of the passenger compartment in winter. We solve both tasks with a separate cooling and heating circuit. That means we need the water pump from the Leaf for the cooling circuit and a second aftermarket pump for the heating circuit. Both pumps are connected to a 12 V power supply.

Two separate circuits also require two expansion reservoirs – however, the one for the heating circuit can be significantly smaller than the one for the cooling circuit (Fig. 15). They are attached to the sheet metal edge of the firewall. The plastic edging of the expansion tank for the cooling circuit must be cut to the extent that a bracket can be attached.

Fig. 11: The water pump with its original bracket from the Leaf temporarily mounted on the front electric motor bracket.

Fig. 12: Aftermarket pump with mounting ring and connector.

Fig. 13: A section of a former leaf holder serves as the mounting bracket.

Fig. 14: The aftermarket pump for the heating circuit is mounted on the gearbox.

Fig. 15: Two circuits, two expansion tanks. The smaller one also serves as a filler neck for the heating circuit.

Fig. 16: A good half dozen connectors, branches and tapers are required to set up the cooling and heating circuit.

The smaller expansion tank for the heating circuit is supplied with a bracket which easily attaches to the edge of the firewall using an existing hole.

Construction of the cooling and heating circuits

Filling the circuits The illustrations on pages 184 and 185 show the structure of the circuits. Making the various sub-connections and connecting them watertight is a challenge given the limited space. But filling the circuits (cooling appr. 2.5 liter, heating appr. 1.5 liter) is only possible with a vacuum, i.e. with a corresponding ventilation and filling device as well as a compressor. Udo bought both of these extras.

The Leaf pump is attached to one of the motor mounts at the front axle carrier using a bracket (Fig. 11, dimensions, p. 171). We ordered an aftermarket pump with a fastening ring and connector (Fig. 12). After working on a small holder from an existing Leaf bracket (Fig. 13) we mount the second water pump to the transmission using one of the adapter plate holes (Fig. 14). So the pump sits – as required – in the immediate vicinity of the HV heater.

So geht‘s / Elektrik und Steuerung

That‘s how it works – Chapter 4

Electrics and controls

4.1 The high-voltage system

4.2 Repurposing the Volvo vehicle control unit

101

4.3 The CAN Bus

104

4.4 Cable connections

106

4.5 Connecting cables in the engine compartment

112

That‘s how it works – 4.1 The high-voltage system

The high-voltage system In the mid-1970s, AC/DC naturally called their first album “High Voltage”. The message: Rock ‘n’ Roll is bursting with energy and dynamics and is a bit dangerous. And yes, the metaphor is correct: high voltage (HV) is dangerous. Therefore, we need to familiarize ourselves with the components and structure of HV systems for vehicles. The HV system of an electric car including the Volvo 850 electric consists of the following components:

• Inverter • DC/DC converter • Junction box (to protect the connections) • Additional components (e.g. HV heater) • Charging socket and cable, charger

• Traction battery (in conversion projects usually distributed over several battery boxes) • Service plug and pre-charge unit • HV cable and fuses • Electric motor

Figure 1 shows how the HV system of the Volvo 850 electric is structured

Pre-charging and relay control In the wiring diagram (Fig. 1) we see the main contactor set at the top left under “Pre-charging”. Relay K2 is the main contactor or the plus relay. Relay K3 is the pre-charge relay that handles the pre-charging (also known as the pre-charge or contactor unit). The relay K2 disconnects the positive pole of the battery. The pre-charge relay bridges relay K2 with a resistor. Figure 2 shows this unit from the Leaf donor vehicle. Why is the topic of “pre-charging” so important? Well, when the vehicle’s ignition key is turned to position II, the precharging relay needs to close first. The capacitors in the power electronics of the inverter are the reason for this. A discharged capacitor would enable a short circuit. So, if the positive relay closes immediately, it would cause a short circuit. The contact surfaces would heat up so much that they weld together. The relay no longer opens when it is switched off and has thus lost its function. This is why the pre-charge relay is mandatory. The resistor in front of it ensures that the inrush current is limited to a few amperes. If the capacitors are charged, i.e. if the voltage is the same before and after the relay, the positive pole of the relay can be released and the car can switch to ready-to-drive mode. As a rule, when turning the ignition key to position III the resulting start signal should be used for this. The positive relay

then bridges the pre-charging resistor and the current can flow unhindered. The pre-charge relay is controlled by a switched plus, i.e. as soon as the ignition key is turned to position II, the pre-charge relay picks up. The positive relay is controlled by the vehicle‘s VCU. In our Volvo this is the adapted FENIX (p. 101). The transition to drive mode, i.e. the activation of the positive relay, depends on a number of conditions that the inverter verifies: • The gas pedal is not touched • The capacitors are sufficiently pre-charged • The ignition key is in position “drive mode” • The battery voltage is below the limit set in the inverter The VCU also closes the positive relay when the vehicle is charged. We do not recommend to transfer control of the relays to the BMS. Some BMS are able to open a relay when the voltage exceeds or falls below a certain limit. However, if the power or positive relay is controlled in this way, there is a risk that it will open under load. But relays are not designed for this application. Also, there could be overvoltages in the inverter during acceleration of the vehicle, which would destroy the inverter.

;)

Fig. 2: Pre-charge or contactor unit. Fig. 1: The wiring diagram of the Volvo 850 electric.

That‘s how it works – 4.1 The high-voltage system

Fuses One of the central issues in every HV system is protection against electric shock. This means the installation of fuses that can be used to reliably switch off the current flow. In electric vehicles, the requirements for fuses are high due to the high voltages and high currents. The components in most electric vehicles are rarely designed for continuous peak loads. For example, the maximum permitted battery current in the Nissan Leaf is approximately 320 A, but a 225 A ceramic fuse is installed. This allows 320 A for a short period of time, but not permanently. Above all, the 225 A fuse must safely switch off in case of a short circuit in the DC lines, for example in the event of an accident.

Fig. 3: Service-plug unit from the Nissan Leaf.

The 225 A fuse is installed in the service-plug unit (Fig. 3 and 4) . We transferred this unit, including the fuse, to the Volvo and placed it in battery box 1.

Fig. 6: A second 225 A fuse is located in the junction box.

As one would expectthe service-plug unit includes the service disconnect or service plug (Fig. 5) which is a removable power bridge. This means that the HV system is only disconnected when the service plug has been pulled – the most important prerequisite for being able to work on the vehicle. A service plug is therefore an absolute “must have“. For the safe operation of an electric car it is important that service plug and fuse are placed as close as possible to the traction battery. In the event of a short circuit, this is the only way to protect the cables and the traction battery from overload. For example, if service plug and fuse were installed in the engine compartment but the traction battery in the rear, then the equipment between front and rear would not be protected against overload. In the event of a short circuit, this could cause the traction battery to overheat and ignite.

Connection to the inverter

In the Volvo, the battery capacity is distributed. However, the most battery units – the 12 module-unit of Box 1 and the six modul-unit of cable Box 2 lengths: – are located in the rear. For this reason, M1 PCU: 370 mm service plug and fuse are housed in box 1. As a backup, we M12 SP: 320 mm placed anotherSP225 A fuse in the junction box in the engine M13: 700 mm 4670junction mm compartment M18 (Fig. M19: 6). The box also contains the fuses M24 J/B: 1040 mm for the chargerPCU andJ/B: the4050 HV heater (40 A) and for the DC/DC mm converter (30 A).

If the entire traction battery was installed in one place in the vehicle, connecting it to the inverter would be easy. We just have to rout cables from the positive and negative poles of the traction battery to the respective poles of the inverter. In our case, the matter is a bit more complex, since the modules from the Leaf donor vehicle are distributed over three battery boxes (Fig. 7): • The positive pole of battery box 1 is connected via the pre-charge unit to the positive pole of the inverter (inside the junction box).

Fig. 4: Service-plug unit from below looking at the 225 A ceramic fuse.

MOTOR COMPARTMENT

M24

PASSENGER COMPARTMENT

TRUNK

M19

–

M1 + – M18 PCU

J/B

• The negative pole of box 2 is connected to the positive pole of box 3.

– +

M12 –

+ M13

BOX 3

Fig. 5: The service plug.

BOX 2

• The negative pole of box 1 is routed to the positive pole of box 2 via the circuit breaker unit.

BOX 1

• Last but not least, the negative pole of box 3 is connected to the negative pole of the inverter (also inside the junction box).

Fig. 7: The HV cable connections between the battery boxes and the inverter (via junction box).

That‘s how it works – 4.2 Repurposing the Volvo vehicle control unit

That‘s how it works – 4.1 The high-voltage system

Reconditioning The DC/DC converter

The combustion engine is the heart of a conventionally powered vehicle. By taking it out our Volvo 850 has undergone demanding surgery. But that’s not all: we will also recondition his brain, the vehicle control unit (VCU).

Since the alternator is removed when converting a combustion vehicle to electric, the question arises as to how the 12 V battery is charged – because the 12 V on-board network is still needed for operating all vehicle electrics. Well, the job of the alternator in the electric vehicle is performed by a DC/DC converter (Fig. 8). It converts high voltage direct current (approx. 400 V) into low voltage direct current (approx. 14 V). In addition, it separates both voltage ranges with a transformer. This is an important safety feature as it prevents the HV traction battery from being electrically connected to the vehicle ground. If the HV system were electrically connected to the vehicle ground, it would be enough to touch the body and ONE HV cable to get a shock. The same applies to the risk of short circuits, for example if the insulation is worn through. Thanks to the transformer, however, the plus and minus poles of the HV traction battery need to be touched at the same time to suffer an electric shock. Fortunately, that‘s not so easy to do. We use a DC/DC converter from a Tesla. They are popular in conversion projects for three reasons: 1. They are designed for use in passenger cars. 2. They can be integrated into the cooling water circuit. 3. They can be controlled via the CAN Bus. The Tesla DC/DC converter has a so-called “Enable” input. This means: It only starts to work when high voltage is present AND this input is activated. This is important, because if the DC/DC converter were to start when only voltage was applied, the pre-charging resistor would be overloaded and burn out. Please remember: Initially, the traction battery is only connected to the consumers via a resistor. We integrate the DC/DC converter into the HV system via the inverter. It will draw about four amps under full load. A cable cross-section of 4 mm2 is therefore sufficient. We protect the DC/DC converter against short circuits with a 30 A fuse.

Fig. 8: The DC/DC converter on the aluminum plate: More than just a replacement for the alternator.

Additional components (e.g. heating) Usually, additional components must be integrated into the HV system, for example a heater. So far, 12 V PTC heating elements or glow plug water heaters have often been used. This works, but is not an ideal solution, since the heat output is not really convincing. We installed a “real” HV heater in the Volvo 850 electric, namely a HVH 50 from Webasto, which Udo bought used and which Johannes implemented into the HV system.

i THE 12 V ELECTRICAL SYSTEM Since the DC/DC converter supplies sufficient power and the vehicle does not have a starter, why still have a 12 V vehicle electrical system at all?

This means: We use the housing and the connectors of the original VCU (Fig. 9), but replace the board with a new control board from Johannes. In addition, there is space in the housing for a WiFi module for communication, a relay for switching the main contactor and an amplifier circuit board for the acoustic warning signal. But for the new brain to be able to send the necessary signals to the new heart – the electric motor with inverter -, some detective work is required. Because we have to find out which signals are present at the two connectors of the original control unit. This is comparatively easy with the wire diagrams of the vehicle being converted. We got these plans for our Volvo 850 (Fig. 10). If these plans are not available, it becomes much more complicated. Then you have to check each cable („ringing through“) to identify which signal is present. Repurposing the vehicle control unit basically means one thing above all: We continue to use the cables from the existing wiring harness as far as possible, but change the assignment of some of them. Instead of the original signals, we are now sending different information via Johannes‘ control board. True to the motto „Never lay a new cable if you can use an existing one“, we recommend not cutting off cables that you think are expendable – even if this poses a challenge to keeping track of them.

Because the 12 V battery is of course still needed – not least because the relays have to be fed from an energy source when starting. The DC/DC converter is not working then. In addition, there are consumers in the vehicle, such as clock, radio and speedometer, which require a 12 V battery. Incidentally, in Germany, for example, it is a prerequisite for the registration of a converted vehicle. The TÜV leaflet 764 “E-Vehicles in the individual approval process” states: “Basic functions like hazard warning and parking lights must be retained even if the power supply for the traction unit is no longer sufficient. This can be secured by a separate energy storage.”

Fuel gauge as charge level indicator An example of repurposing VCU signals is the fuel gauge which is analogue in practically all combustion engine vehicles. There is a float in the fuel tank that lowers as the fuel supply decreases. The float is attached to a potentiometer, i.e. a mechanically variable resistance. This converts the level into an electrical signal. The potentiometer is connected to the vehicle ground and to a power source. However, we removed the float with the petrol tank. To be able to continue using the fuel gauge, we must now electronically load the power source of the potentiometer. For this purpose we use pulse width modulation (PWM). It occurs when the power source is connected to ground and disconnected from ground at defined time intervals. This results in a medium voltage that controls the display instrument. Since the VCU receives the state of charge from the BMS via the CAN Bus, it can translate the state of charge into the PWM signal and thus control the fuel gauge. Naturally, the state of charge display on the fuel gauge is only an approximation. But it is fun and pleasure to see a few needles still move in the instrument cluster after the conversion. This also applies to the revolutions counter. We also address it via PWM, so that we can display the revolutions per minute (rpm) of the electric motor.

Abb. 9: The Vehicle Control Unit (VCU) from the Volvo (Fenix 5.2).

100

Fig. 10: Wire diagrams Volvo 850, 1993; Page 30 “Fuel and ignition system Fenix 5.2”, which is the VCU.

Figure 11 on the following page shows the repurposing of some VCU positions from the Volvo 850 petrol for the Volvo 850 electric.

101

That‘s how it works – 4.2 Repurposing the Volvo vehicle control unit

12 V circuits VOLVO 850 ELECTRIC COMPONENT/FUNCTION

SIGNAL

Acoustic warning signal

PWM

POSITION VCU

VOLVO 850 PETROL FUNCTION (CABLE COLOR)

A36 A21

Camshaft sensor 7/21 (Y-R) Camshaft sensor 7/21 (BL-Y)

Brake pedal

12 V

A24

Injection system 8/8 (GR-R)

CAN Bus

CAN Hi CAN Lo

A32 A33

Lambda probe 7/15 (GN-SB) * Lambda probe 7/15 (GN-GR) *

Instrument cluster Motor control light (BN-W)

Drive mode (lamp)

OC *

Drive mode (DC relay/main switch)

OC *

Front knock sensor 7/24 (VO)

Drive mode

12 V P-MOSFET

A38

Injection 8/7 (GR-OR)

A15

Intake manifold pressure sensor 7/81 (VO)

Accelerator pedal

5V Analogous 0,8-4,2 GND

A16

Throttle 7/54 (OR-W)

A18

Engine temperature sensor 7/16 (BN-SB)

High-voltage heater

LIN

Injection 8/10 (GR-W) (LIN bus)

Charging

12 V

A23

Injection 8/9 (GR-SB)

Start (Key position III)

12 V

A17

Knock sensor, front 7/24 (P-SB)

12 V

A12

Fuel system main relay (BL-R)

5V Analogous 0,7-3,3 GND

A15

Intake manifold pressure sender 7/81 (VO)

Intake manifold pressure sender 7/81 (W)

A18

Engine temperature sensor 7/16 (BN-SB)

Vacuum pump (brake booster)

OC * MOSFET

A10 A27

Injection 8/6 (GR) Junction Injection+ (GN)

State of charge (via fuel gauge)

PWM

B27

Fuel pump relay 2/23 (Y-GR)

Revolutions electric motor (via rev counter)

PWM 56 Hz = 1000 rpm

B21

Instrument cluster display „Engine revolutions“ (W-SB)

VCU (12 V Standby)

Vacuum sensor (Brake Booster)

Fig. 11: Repurposing the Volvo control unit (Fenix 5.2).

* OC means “Open Collector”, i.e. ground connected via transistor.

102

BMS_E =

BMS Enabled

Charger

Inverter

OEL

Hydraulic pump

OEL_E =

Hydraulic pumpe Enabled

OEL_SB =

Hydraulic pump Standby

Pre-charge and plus relais

DC/DC =

DC/DC converter

HVH

High-voltage heater

VAC

Vacuum pump

VCU

Control unit

WP1

Water pump cooling circuit

WP2

Water pump heating circuit

12 V Charging

WP1

VCU

VAC

OEL_SB

WP2

BMS_E

12 V Permanent OEL BMS HVH 12 V Standby

OEL_E

12 V Drive mode

Fig. 12: The 12 V circuits at a glance.

The importance of the 12 V circuits Another question arises in connection with the conversion of the VCU: Which components should or have to be supplied with power at what time? This needs to be well thought out and implemented accordingly. Otherwise it could happen that you can only charge when the ignition key is inserted – which would be disadvantageous, of course. In principle, one can distinguish between four operating states and thus also four 12 V circuits (Fig. 12):

If the driver now engaged third gear and slowly depressed the accelerator pedal, the vehicle would move off.

12 V Charging The fourth 12 V circuit (“12 V Charging”) is established when the charging cable is plugged in. Then the pre-charging and plus relays, VCU and DC/DC converter, BMS and cooling water pump as well as the charger are active.

12 V Permanent The first 12 V circuit is made up of electrical equipment that is permanently connected to 12 V, for example because the manufacturers require this for operation. It doesn’t matter whether the key is inserted or not. We call this circuit “12 V Permanent”. It includes the BMS, the hydraulic pump and the HV heater.

12 V Standby The second 12 V circuit (“12 V Standby”) is established when the key is inserted and turned to position II. It consists of the pre-charge and plus relays, VCU and inverter (which controls the electric motor) as well as the hydraulic pump and BMS (now in standby or “enable” status).

12V Drive mode The third 12 V circuit (“12 V Drive mode”) includes the previous circuits and is created when the ignition key is briefly turned from position II to position III (start) and then returns to position II. The circuit activates (enables) the pre-charging and plus relays, the DC/DC converter, the hydraulic and vacuum pumps and the two water pumps.

i UNIVERSAL CONTROL BOARD We repurpose an existing VCU and develop specific control boards depending on the donor vehicle. There is no question that this approach is complex and time-consuming. It is therefore quite possible that this will only be an intermediate step in a development that is still largely in its infancy. Some members of the openinverter community are already thinking ahead and can also show results. Damien Maguire presented the first version of an all-in-one control board in June 2022. With his Anglo-Saxon sense of humor, he calls it “ZombieVerter VCU V1”. It can be used to control five inverters, heaters, chargers and traction units via CAN and serial interfaces. And the list is set to continue to grow as part of an open source process. Learn more at www.openinverter.org.

103

That‘s how it works – 4.3 The CAN Bus

Twisted wires

WAGO CLAMP

The term CAN Bus has already been mentioned – and this brings us to another important aspect of the electronics and control units in electric vehicles. Even if the combustion engine vehicle does not yet have a CAN Bus due to its age, it must be installed in a conversion project.

CAN BUS PART A

The order of the components must be determined in such a way that there is only a 120 Ohm resistor at the beginning and end of the CAN Bus line. But it is also mandatory there. Experts speak of the “termination” of the CAN Bus or of the fact that it must not be terminated at intermediate stations. In our case, the resistors are in the VCU and in the BMS: Johannes built a resistor into the VCU; in the BMS of the Nissan Leaf it is already included.

In order to rule out signal interference, the CAN Bus must not be routed parallel to the HV cables. That’s why we laid it separately from the three HV lines.

Many advantages Let’s take a closer look at the CAN Bus. It is common in newer vehicles such as Johannes’ 2004 VW Touran. This has advantages in case of a conversion project. As already explained, the CAN Bus consists of only two lines. A serial data protocol, which can also be found in other computer networks, runs over these lines. This protocol transmits exactly the data that used to be carried over individual cables. For example, there is no longer a cable that assumes a 12 V level as soon as you step on the brakes. This task is performed by just one bit changing its state from zero to one.

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Since all control units are connected to the CAN Bus, they can use the corresponding information and need not be wired individually. Software updates also make it possible to use information that was not even considered when designing the vehicle. For example, the rear wiper may come on when the front wiper is already on and the driver engages reverse gear. All without separate cables, only through software.

Understanding data protocols In order to understand the CAN Bus, we have to deal with the data protocols. Data packets are sent on the CAN Bus in the form of messages. Each message consists of several bits, i.e. data units that can be zero or one. If you combine several bits, decimal numbers can be represented – with eight bits, for example, all numbers between zero and 255. The position of the gas pedal is transmitted, for example, with a message that is structured as follows:

Content

Object ID

Data

Number of bits

11 bits

15 bits (up to 64 bits possible)

Example bits

00000000010

00001010 00010110

Meaning

Object#2

On, Start, Brake, clutch, gas pedal

The first eleven bits (00000000010) form a kind of sender address. It determines how the following bits are to be interpreted. In our example the data bits are: 00001010 00010110. Bits zero to three are not used (please note: in computer science, counting always starts at zero).

CAN BUS PART C

VCU (A33)

GN-SB

VCU (A32)

TO BMS

CV BL

B10

CH (B CONNECTOR)

DC/DC VCU

The reason: During a conversion, components are used that can only be controlled via a CAN Bus (Fig. 13), such as BMS, DC/DC converter, charger and inverter. The CAN Bus consists of two wires twisted together, which are used to control the relevant components. Two things have to be considered during implementation:

GN-GR CV GN

CAN BUS PART B

CV BL

DC/DC

Fig. 13: The CAN Bus in the Volvo 850 electric.

• Bit 4 indicates that the ignition key is in the “on” position. • Bit 5 shows that it is in start position (it is not). • Bit 6 signals that the brake has been pushed. • Bit 7 shows that the clutch has not been pushed. • The last 8 bits together result in the gas pedal position. There are around 50 such messages on the VW Touran’s CAN Bus, which are generated by the various control units, such as the engine control unit (ECU), ABS, ESP, airbag. The ECU generates around ten messages. Of course, they are missing if the ECU is removed during a conversion project. But these messages can be generated with our own control unit, and with that a variety of instruments and warning lights can be controlled. In fact, many messages must continue to be sent because the controllers either rely on them or simply monitor for the presence of these messages. ABS and ESP in particular switch off immediately if the corresponding message is missing.

Identifying messages In order to be able to generate CAN Bus messages, you need to know their structure. One source for this information is the openinverter platform (www.openinverter.org). The members of this community have published protocols for various vehi-

cles. Even if a specific model may not be included, the protocols are still helpful as long as the brand is represented. Because the CAN Bus protocols are usually identical for the vehicles of one manufacturer. However, if you cannot find what you are looking for on openinverter.org, you have to decode the CAN Bus of your vehicle yourself, for example by stepping on the gas and checking what has changed in the messages. The decoded messages are generated by the new VCU after a conversion project. There is already ready-made software for this on openinverter.org.

Connection to the CAN Bus Since Johannes used the existing ECU connector in the VW Touran for the new VCU, the CAN Bus was already present. So it only had to be connected to the control board. It would have been more challenging to “tap” the CAN Bus in order to integrate new components such as inverter, charger, etc. To do this, you have to “loop into” the CAN Bus at a suitable point. That means: Separate the CAN Bus, lead it over the devices to be integrated and then lead it back to the same place.

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That‘s how it works – 4.4 Cable connections

Paying close attention In a conversion project, the cables require special attention. They are not only a critical factor for the reliable operation of the vehicle, but also for safety.

Which cables are we talking about? Well, deploying the modules from the Leaf traction battery in three battery boxes means that the original wiring needs to be adjusted. This affects the BMS, but also the HV connections between the battery boxes and the traction unit. In addition, we also have to deal with the inverter cable. When converting a vehicle to electric a decision has to be made: producing the cables yourself or have them made by experts. The following explanations and information are intended to help you make the right choice. As far as HV cables in the signal color orange are concerned, it must be said that such cables are really hard to come by for individuals (at least in Germany). It looks better with photovoltaic (PV) cables, which are also suitable. Readily available is black-coated welding cable. However, we advise against using it for safety reasons. In contrast to PV cables, welding cables are not designed for HV applications.

Fig. 14: Three cables with a cross-section of 35 mm²: Their circumference differs depending on the type of insulation. On the left is the shielded LAPP Ölflex cable that we use for our HV lines, in the middle an original cable from the Nissan Leaf and on the right a (not recommended) welding cable .

The Volvo 850 electric’s power demands includefeatures the 80 kW electric motor fromthe Nissan Leaf, the heating in winter (5 kW), the DC/DC converter (2.5 kW) and heat losses (2 kW). Therefore, a peak output of around 90 kW is required. With a nominal voltage of 360 V, the current is 250 A:

The heating is a function of current, time and resistance. The maximum permissible heating depends on the insulation material. The insulation of HV cables for electric vehicles is designed for more than 100 degrees Celsius. But as this high temperature resistance is a safety feature, it should not be exhausted. Our recommendation is to limit the heating of the HV lines in the vehicle to 20 degrees Celsius above the ambient temperature. In our case, this results in a cable cross-section of 35 mm² with a peak current of 250 A.

Power (90 kW) = voltage (360 V) × current (250 A)

Dielectric strength refers to the voltage with which the cable was tested during manufacture. Leakage currents can theoretically arise above this voltage and couple to the body of the vehicle, for example. The temperature resistance indicates the temperature at which the insulation begins to melt. Finally, the insulation should be made of a flame retardant material so that even in the event of an overload, no fire can occur.

That’s why we can design the cables for our Volvo for an output of 40 kW and a current of 111 A. Then we end up with a cable cross-section of 35 mm², which Nissan also used in the Leaf.

Cable with cable lug

The cable cross-section

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Well, the calculators are assuming that the load is continuous – that is, that a current of 250 A will flow through the cable for hours. This is not possible with an electric car due to the battery capacity. Our 30 kWh battery would be discharged after 15 minutes. In addition, the 90 kW are only used as peak power when accelerating. For orientation: When traveling at 100 km/h, the Volvo draws around 20 kW of power. At 130 km/h it is 30 kW. On inclines, e.g. on hilly highways, 60 kW to 70 kW are sometimes required.

When used in an electric car, we have to keep in mind that HV cables are not only about the right cable cross-section, but also about the dielectric strength, temperature resistance and flame retardancy of the insulation.

A safety-relevant parameter for HV cables is the cable cross-section (Fig. 14), i.e. the volume of the copper wires in the cable. The electrical resistance of the cable depends on this. This resistance determines the amount of heat generated when current flows through the wire.

If we enter this value in a cross-section calculator, it results in a cross-section of 120 mm². In the Nissan Leaf, however, only cables with a cross-section of 35 mm² were used. How does that fit together?

Calculating the cable cross-section is achallenge. Another is connecting cable and cable lug safely and reliably. It starts with cutting the cables. A conventional side cutter is overstrained here. A ratchet cable cutter is required, which cuts cables with larger cross-sections precisely and without great effort (Fig. 15).

Fig. 15: A ratchet cable cutter is required to cut cables with a cross-section of 35 mm².

The actual process of connecting cable and cable lug is called compression. We not only haveto pay attention to the metallic purity of the components in order to avoid contact corrosion. It is also important to strip the cable cleanly and to the correct length. The stripped part should be about ten percent longer than the slot in the cable lug. Because the cable lug stretches by the same amount when it is pressed. For a high-quality connection, the cable lug and crimping tool should come from the same manufacturer and match up with each other. During the pressing process, you need to take care to fully complete it. This is the only way to achieve the required compression. And finally there is the question of the type of pressing process – hydraulic or with muscle power? In view of the fact that the HV cables are a “mission-critical” factor in our project, we have a clear opinion: With a cross-section of 35 mm², we recommend hydraulic pressing – and thus the support of an electrician (p. 149), because who has such a press available at home?

welding cable .

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That‘s how it works – 4.4 Cable connections

When making the BMS cables, we also have to ask three questions to save ourselves extra work:

Fastening cables Finally, a safety-critical point with HV cables is their fastening: We cannot stress enough that it is extremely important to fasten the HV cables with nuts that have an integrated disc spring (Fig. 16). Because this is the only way to prevent the connection from loosening over time due to the vibration of the vehicle.

• When do we attach the connectors to which end? • When do we insert the cables into the corrugated tube? • When do we slip on cable glands to fix the cables to the walls or lids of the battery boxes?

Loose HV cable connections are a big risk. Not only can they destroy the BMS, but the overheating of the contact surfaces can also lead to a fire in the worst case. So we have to work very carefully here. Therefore, we strongly recommend: Store and label all nuts with disc springs from the Leaf donor vehicle separately, including the protective caps made of transparent plastic. This should ensure that all HV cable connections hold.

Fig. 16: Be sure to keep the disc springs from the Leaf donor vehicle. They represent an important element for a reliable and tight connection of the HV cables.

Fig. 17: The battery control cable is connected to battery box 1. To protect against moisture, the adapted plug must be sealed with silicone, see figure 18.

Fig. 19

change the pin assignment and integrate the CAN Bus (Fig. 17). This requires knowledge of the connector mechanics and careful work. The individual pins are secured with small rubber pieces, which are intended to prevent moisture from entering.

For twisting, we fix the two cables to our workbench with a screw clamp (Fig. 18). On the opposite side we attach the cables to a hook clamped in the chuck of a drill (Fig. 19). We slowly start the drill and twist the cables. We keep the cable pair taut and tighten a cable tie every 30 cm so that the twisting does not come loose again.

As already explained, the CAN Bus is a double wire or a twisted pair cable. That means we have to twist two cables (in our case an orange and a green one) together. This is necessary in order to prevent voltage interference fields or “inductively coupled differential mode interference”.

As with the HV cables we have the same “make or buy” issue with the BMS cables. We had to manufacture them ourselves as we couldn’t find a company that would make BMS cables for a single vehicle at a reasonable price.

But first we have to set up a workspace so that we can get started at all. To do this, we need not only a dozen wires (copper strands) of different colors with a cross section of 0.14 mm² (Fig. 20), but also connectors, housings and terminals (part numbers, p. 194) as well as pliers for cutting, stripping and crimping (Fig. 21).

However, with the battery control cable, we would have benefitted from our (almost) complete donor vehicle. Because it included the cable with the round rotating connector that was attached to the connector flange of the Leaf battery pack (Fig. 17). However, for some reason Udo forgot to remove the cable.

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Fig. 20

Adjusting the battery control cable gives us a taste of what to expect from the BMS cables, namely filigree detail work.

BMS cables

So we have to resort to the connector of the Power Delivery Module (PDM) which features the same type of connector. However, this is annoying nevertheless because we have to

Now, after insulating the connector with silicone and twisting the CAN Bus cable, our battery control´cable is almost ready. We wrap itwith adhesive tape every 30 cm and lead itfirst through the black and then through the orange corrugated tube.

Fig. 18: The battery control cable with silicone insulation. The black wire is the ground connection that attaches to the ouside wall of box 1 (see also p. 49 and p. 157).

Once we have everything together, careful planning is required to avoid double work. This starts with correctly measuring the BMS cables. Based on the determined lengths and the number of occupied positions in the connectors, we need around 150 meters of wire. Our recommendation: Order around 20 percent more right away. Because there is always some loss and reordering costs time and nerves.

Fig. 21: Without proper tools, crimping BMS cables becomes a gamble – which ultimately only causes frustration. So please don’t save at the wrong end.

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That‘s how it works – 4.4 Cable connections

TOOLS Happy crimping It may seem self-evident, but it is of course crucial that we carefully note the positions of the individual wires in the connectors. In order for the signals to be transmitted correctly, they must match exactly.

Crimping pliers 0.1-2.5 mm². or AWG 27-13 (e.g. Knipex 97 52 34) Please check the internet about correct crimping!

Connecting pieces To put through the BMS cables from box 2 (2 pieces) and box 3 (1 piece) to box 1, we need connecting pieces of cable. One end of these cables is inside, the other is outside of box 1. The connecting pieces are 50 cm (box 2) and 70 cm (box 3) long and are cut, stripped, soldered and crimped as just described.

Needle-nose pliers Ratchet cable cutter

The cable production process involves the following steps: Cutting, stripping, soldering, crimping: • Cut wire to length and strip 3 mm of insulation • Coat very thinly with solder • 0.25 mm opening of the crimping pliers: Insert the terminal flush with the edge of the pliers • Push in the wire so that 2 mm of insulation are covered • Press pliers shut (tip: lean on the edge of the table to make it easier to push through in one go) • Check the wire: Is it correctly crimped? Is it inserted too much or too little? Pull on it lightly to check whether the connection holds. Insert into connector: • Even if the correct pliers were used for crimping, this is our experience: The wires cannot easily be inserted into the connector. But they have to! • Therefore, before inserting, we gently press the terminal together again with the needle-nose pliers at the crimping point. • If the width is right, the wires can be pushed in by hand, and we pay attention to a click that can be heard. Only then are the wires properly in place. • In some cases we need to apply a mini screwdriver. However, it must not be wider than 2 mm! Otherwise the plastic connector wall may be damaged and short circuits may occur.

But we have to becareful: The wires can only be inserted into the connector on the side of box 2 and box 3. At the other end, we have to take note of the wire positions in the connector and number them accordingly – for example, by labeling a transparent cable lug with a waterproof pen and putting it on. The advantage: the cable lug protects and identifies the terminal, but can also be easily removed again (Fig. 22). As stated earlier, we have to avoid any mistakes or confusion.

Fig. 22

Side cutter Soldering iron Wire stripper

Inserting the cables into the connectors takes place inside box 1 as follows: • Slip on cable glands and fasten them inside and outside the wall of box 1 and guide the wires through the holes (Fig. 23). • Set up a workspace: Good light and a chair are important (Fig. 24).

Fig. 23

• Place a cardboard box on the 12-module unit and position the tools (needle-nose pliers for pressing in and, if necessary, a screwdriver for pushing in) (Fig. 25). • Then we insert the wires into the connectors (process as just outlined).

MATERIAL Copper strands Different colors, cross-section 0.14 mm², at least 150 meters

Special case: Box 1 to box 2 connector (4 positions) From box 1 to box 2 there are two BMS cables – one with 25 positions (in a 32 position connector), one with 4 positions. The challenge with the 4 position cable (2 white wires, 2 blue wires) is that we are unable to research and source the connector. We therefore decide to proceed as follows:

Connectors, housings, terminals for box 2 and 3 (part numbers, p.176) Fig. 24

We cut the connector off with about 20 mm of wires, extend the cable by soldering in four wires of 500 mm length, and finally solder the connector back on again.

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Corrugated tube 10-12 mm inner diameter, approx. 6 m, black 15 mm inner diameter, approx. 6 m, orange Adhesive tape Orange and black

• When all wires are inserted in the connector, we press in the connector lock and check each wire for contact with the continuity meter. • Note: the bottom row in the connector is easier to insert when the safety clip is completely removed. But we have to remember to put it in before starting the top row

Screwdriver max. 2 mm

Cable glands 2 × M32 × 1.5, 11-21 mm, e.g. Lapp 53111040 1 × M20 × 1.5, e.g. RND 465-00375 1 × M16 × 1.5, 4.5-10 mm, e.g. Lapp 53111210

Fig. 25

Solder Diameter 1 mm

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That‘s how it works – 4.5 Connecting cables in the engine compartment

Organized cable clutter

TOOLS Hacksaw

Connecting the cables in the engine compartment – that’s easier said than done. We have to cope with the fact that a good dozen components or system elements have to be connected to each other (overview, p. 179). So we make sure to keep track of things and proceed in a systematic way.

File Screwdriver Wrench 10 mm

Fig. 27: The thread of the right-hand corner screw of the DC/DC converter (black screw) can be used to fasten the cable box.

In order to be able to connect them, HV, BMS and charging cables must of course first have arrived in the engine compartment. See page 114 for how this is done.

MATERIAL Junction box (plastic) 134 mm × 89 mm × 40 mm, IP54

A second requirement is a fully wired junction box (J/B). That means: The cable of the DC/DC converter, the HV cables from boxes 1 and 3 as well as the charging cable and the cable for the HV heating have to be connected. This is essential, because only then can we place the charger on the J/B. If these two conditions are met, we can turn to the question of how the components are connected in detail and which connectors are required for this. To carry out this work in a traceable manner and with the necessary quality, we document the cable runs for each individual component (p. 172). Based on these diagrams we proceed step by step. Similar to the HV cables, all other cables should also be routed through corrugated tubing. To do this, we order around 40 meters of black corrugated pipe with inner diameters of 4, 7, 10 and 13 mm – unslotted, but also slit to be able to cover every requirement. In addition, cable ties do a good job in terms of cable routing and fixation. As we need quite a large number, we do not calculate too tightly and have different sizes available in sufficient quantities. The aluminum carrier rail (for the acoustic warning signal, the HV heater and the mini cooler) is also suitable for cable routing (Fig. 26). In this way, at least some order can be created in view of the impressively large number of cables. Last but not least, black insulating tape should not be missing when laying and connecting the cables in the engine compartment.

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Drill Metal drill bit 6 mm

Cable glands (cable box) 9 × 16 mm, 2 × 20 mm Fig. 26: The aluminum carrier rail for the acoustic warning signal, the HV heater and the mini cooler provides valuable space for cable routing.

Cable ties Several sizes

Cable box

Insulating tape Black

In the engine compartment, in front of the charger, there is a central “node” where numerous cables are connected to each other via Wago terminals (p. 179). To protect these cables from humidity, we install a junction box made of plastic with a total of eleven cable glands. We aptly call the box “cable box”. It is fixed both on the DC/DC converter (Fig. 27) and on the right via a mini holder on the fastening screw for the charger (Fig. 28).

Fig. 28: On the right, we fix the cable box to the fastening screw for the charger using a mini holder.

Fuses 1 × 10 A, 1 × 80 A

12 V Battery

Wago terminals Cable box 5 × 2 pos., 3 × 3 Pos., 2 × 5 pos. 12 V battery (positive pole): 1 × 5 pos.

Even if there is not as much ”traffic” as in the cable box, several cables need to be mounted to the positive pole of the 12 V battery as quite a number of components require 12 V supply (p. 173). The DC/DC converter and the 80 A fused hydraulic pump are directly connected to the positive pole of the 12 V battery. The other components are connected via a 10 A fused Wago terminal (Fig. 29).

Corrugated tube Black, diameter 4, 7, 10, 13 mm, slotted and unslotted

Ground connections When it comes to wiring, we must not forget the ground connections. On the contrary: they have to be carried out very carefully. An overview of the required connections is shown on page 181.

Mini holder (cable box) Metal, 25 mm × 10 mm (L × W), two holes: 5 mm and 8 mm, Phillips screw 1 × M5 × 10 mm

Fig. 29: Protection of 12 V consumers on the positive pole with a 10 A fuse.

Cable carrier unit (for mounting on the underbody) Aluminum flat bar (at least 1.2 meters), 20 mm × 2 mm (W × H) Aluminum U-profile (at least 4.2 meters), 25 mm × 25 mm × 25 mm, 1370 mm (L) 20 × M6 × 10 mm round-head slotted screw, 6 × plastic nuts (originally for the fuel lines)

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That‘s how it works – 4.5 Connecting cables in the engine compartment

Fastening the carrier unit • Separate the heat protection shield and the aluminum unit from each other (Fig. 30).

Cables on the underbody

• Place the aluminum unit under the vehicle – it is best to use cardboard to increase it by approx. 25 cm (Fig. 3). Then the cables can be inserted more easily into the aluminum U-profiles, which serve as guide rails.

Back to the HV, BMS and charging cables: How do they actually enter the engine compartment? Fortunately, we can use the space freed up by removing the exhaust system and fuel line. This not only allows for an easy installation, but also has another advantage: the ground clearance is not reduced, which is important for the road readiness approval of the vehicle.

• Insert the charging cable in the aluminum U-profile on the right, viewed from the engine compartment, the HV cable from battery box 1 to the inverter in the middle and finally the HV cable from battery box 2 to battery box 3 on the left

HV cable and charging cable In the Volvo 850, the exhaust system ran in a heat protection shield. Made of thin sheet aluminum, it is ideally suited for a cable duct in which the charging cable and the HV cables from box 1 to the inverter and from box 2 to box 3 can run well protected. All we need is a unit that connects to the shield. The heat protection shield is screwed to the underbody in four places, using threads that protrude from the underbody. At these four points we install “bridges” to which three aluminum U-profiles are screwed. Together with the protection shield they form the carrier unit (Fig. 30).

• The cables fit perfectly in the U-profiles (25 mm). Nevertheless, we additionally secure them on the four bridges with cable ties (Fig. 34). Fig. 30: The unit made of aluminum U-profiles and “bridges” attached to the heat protection shield.

• Then fasten the carrier unit to the underbody with the (rubber) nuts (Fig. 34 and 35 on following page).

The bridges are cut from aluminum flat bars (20 mm wide, 2 mm thick). Since the shield is wider at the front than at the back, the bridges must be of different lengths, namely 240 mm, 245 mm, 320 mm and 325 mm. On the left and right we drill 6 mm holes in the bridges to attach them to the shield (Fig. 31). We use M6 round-head slotted screws (length 10 mm) and nuts for this. The bridges are then screwed to three aluminum U-profiles (25 mm × 25 mm × 25 mm, 1370 mm long), in which the cables are routed. That’s why we drill three 6 mm holes in each of the four bridges and in the aluminum U-profiles. Here, too, we use M6 round-head slotted screws with the corresponding nuts (Fig. 30).

• Position the heat protection shield above the aluminum unit and screw both together to form the carrier unit: This is not easy due to the narrow space underneath the vehicle. But it is doable.

Abb. 33

Fig. 31

At the rear end (in front of Box 2), we have to make sure that the U-profiles end about 100 mm before the end of the heat protection shield – otherwise the cables that are routed around Box 2 cannot be inserted into the U-profiles (bending degree is not enough) (Fig. 32).

Fig. 32

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Abb. 34

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That’s how it works – 4.5 Connecting cables in the engine compartment

Cable between box 1 and box 2 Now we are almost done on the underbody. However, one task remains: As mentioned on page 110, the BMS cables from box 1 to box 3 and from box 1 to box 2 (24 pos.) are plugged together outside of box 1. We have to protect these connections against water and dirt. For this we again use plastic junction boxes (Fig. 36). In addition, we fasten the battery control cable, the HV cable to the inverter and the BMS cable to box 3 behind the rear axle with clamps on the frame (Fig. 37). We use an existing M6

thread for this. In order to be able to fasten three cables with one screw, we need two standard clamps as well as a “custom-made clamp” (Fig. 38).

Notes

Battery control cable and BMS cable (from box 1 to box 3) The fuel line was routed in a slightly recessed channel and was fastened to six self-tapping screws protruding from the underbody and with a plastic clamp. We use the screws and the clamp to route both the battery control cable and the BMS cable (from box 1 to box 3) into the engine compartment (Fig. 35). All we need additionally are clamps and the plastic nuts that we saved after removing the fuel line.

Fig. 36

Fig. 37

Fig. 35: We use the channel of the heat protection shield of the exhaust system and the recesses for the fuel lines to route the cables from the rear to the engine compartment in the front.

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Fig. 38

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So geht‘s / Elektrik und Steuerung

That’s how it works – Chapter 5

Charging infrastructure

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5.1 Preparing and installing the charger

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5.2 Wiring the charging socket

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That’s how it works – 5.1 Preparing and installing the charger Just one control board left

Control board swap If you want to charge your vehicle at a normal socket (220 V in Germany) or at public AC charging stations, you need a charger in the car that converts alternating current into direct current. Since the charger is operated in the public grid, it must comply with all relevant standards.

Therefore, it is advisable to resort to a product that has been specially designed for this purpose. Since Tesla is the market leader for electric cars, there are always used chargers on the market. Another reason that speaks for Tesla: Generation 2 chargers can already charge in one, two or three phases, with an output of 10 kW on a 400 V system, which is just right for our usage and driving profile.

(on the right in the picture) connects the charger to the traction battery via the junction box and inverter. The plug connection (top left) leads to the charging cable. The open source board is available in two versions – either fully assembled (more expensive) or not fully assembled (cheaper).

But we’re not quite there yet. The open source board controls the loading process. But we need another (small) board that – as soon as the charging cable is plugged in – switches on the components that are required for charging. In addition to the charger, these are the water pump for cooling, the VCU, the BMS and the DC/DC converter. This small board is connected to the open source board by four cables (Fig. 4). So we fire up the soldering iron again and solder the cables to the following positions (counting from bottom to top): • Left row: red at position 4, green at position 10. • Right row: orange at position 7, black at position 9. On the small circuit board, the cables are connected as follows (Fig. 5): • SW: orange • 12 V: red • ground: black • CP: green.

But again: We cannot just install the Tesla charger and switch it on. In order for us to use it, it is necessary to replace the control board. Fortunately, after the successful transplantation in the inverter, we already have experience with changing control boards. Thanks to the openinverter community, there is an open source board that we can use for this purpose (see Material).

Fig. 2

The Tesla board is attached with six Torx screws. Once removed, we can see the two connections (Fig. 2): The connector We opt for the cheaper version, source the requiredcomponents (see Material) and assemble the board ourselves. It can be done with a good soldering iron, the right solder and a steady hand.

Fig. 1

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The M8 screw is already protruding from the plate at the rear left. We just slide a spacer sleeve over it and then place the charger on the DC/DC converter and junction box. At the front right, we insert an M10 screw through the opening on the charger, insert a spacer sleeve here too, and then guide the screw further through the aluminum plate and fix it.

TOOLS Torx screwdriver (TX20) Soldering iron

MATERIAL

The inner workings We open the charger by loosening the eight Torx screws and removing the cover. We extract the board on the top left and replace it with the open source control board (Fig. 1).

This step completes replacing the control board. So we can put the lid on and screw it on. If the DC/DC converter and junction box are already wired, the charger can be mounted on the aluminum carrier plate.

So we solder the plugs for the two connections mentioned as well as the plug for the WLAN module onto the replacement board. Then we install the board and screw it tight (Fig. 3).

Fig. 4

Open source controlboard 1 (www.evbmw.com) to control the charging process Some additional parts are required, in particular: • Samtec power connector (part number: IPS1-115-01-SD-PL) • FCI Headers & Wire Housing 36P STR SR TMT HDR / Socket and Wire Housing (part number 77311-401-36LF) • JST Automotive Connector 2 mm CPT DBL RW MALE / connector (part number SM24B-CPTK-1A-TB(L)) • TE Connectivity Automotive Connector 025 24 POS CAP ASY / connector (part number 1-1318853-3) • WLAN module openinverter.org/shop Open source control board 2 (www.openinverter.org/shop) to switchon the components involved in charging. Fixing charger on aluminum carrier plate 1 × M8 × 120 mm (rear left) countersunk socket head screw with shank Spacer: height 65 mm, diameter 15 mm 1 × M10 × 120 mm (front right) countersunk socket head screw with shank Spacer: height 60 mm, diameter 15 mm

Fig. 3: The assembled control board installed.

Fig. 5

Solder

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That’s how it works – 5.2 Wiring the charging socket

Perfect fit: Charging cable and socket In the “Electrics and controls” chapter, we already mentioned that we opted for the Type 2 charging connector system. This affects the cable we need for charging.

The Type 2 charging connector system is characterized by the fact that it has two so-called contact pins in addition to the five conductors for alternating current (PE, N, L1, L2, L3). On the one hand there is the Proximity Pilot or Plug Present (PP). It not only reports that a charging cable is connected, but also what the charging current may be at most – depending on the resistance or cable cross-section of the charging cable. The Control Pilot (CP), in turn, informs the vehicle of the maximum possible charging capacity. Without going into the details of controlling the charging process, it can be said that both contact pins play an important role. For the charging socket, this means that the cable must consist of seven conductors. We cover the AC connections with a rubber cable that is suitable for heavy-duty and outdoor use: five-core H07RN-F cable with fine-wire copper strands and a cross-section of 2.5 mm2. We connect the contact pins with copper strands in red or yellow (cross-section 0.14 mm2).

Wire the charging socket in five steps 1. Attach cables to each other We fix the two contact pin cables with adhesive tape on the sheathing of the H07RN-F cable. 2. Prepare charging socket We take our charging socket, open the clamp of the protective sleeve, remove it and unscrew the plug from the housing. Regarding the position of the conductors, see page 180. In our view it helps to provide the individual wires with a cable lug. Then they can be soldered more easily to the plug of the charging socket. This applies in particular to the contact pins. Please make sure to connect yellow (PP) to the “Long Terminal” and red (CP) to the “Short Terminal” (Fig. 6).

of the distance to the engine compartment is protected from the weather by the aluminum carrier unit. We can therefore use orange corrugated pipe with an inner diameter of 15 mm for this section.

Fig. 8: To protect against stone chipping, we run our charging cable through a metal hose with a PVC coating.

5.Connect to the charger Our charging cable splits in the engine compartment: After grounding H07RN-F cable on the vehicle body (Y-GN), we connect the remaining four conductors via one Molex connector (6 position) to the charger AC input (Fig. 9, left connector). However, we have a small challenge to meet: The three neutral conductors (white) in the charger at positions 2, 4 and 6 would only meet one blue neutral conductor of the charging cable. We solve the task with a Wago clamp. That means: The blue neutral conductor of the charging cable goes into the Wago terminal, from which three blue cables lead to positions 2, 4 and 6 of the Molex connector. The two contact pin cables run around the charger in corrugated black tubing into another 12-position Molex connector (p. 181).

3. Insert charging socket After all the wires have been soldered, the plug can be reinserted into the charging socket housing.

Fig. 9

On the Volvo, the filler neck sat in a rubber sleeve, which we can now use again as a protective covering and for fixing. The circumference of the rubber sleeve matches the circumference of the charging socket. However, we need to enlarge the opening on the back of the rubber sleeve. Only then does the plug fit through (Fig. 7). In the next step we pull the rubber sleeve of the Type 2 charging socket back on.

Fig. 6: The contact pin cables (yellow and red) are soldered to the long and short terminals of the charging socket.

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4. Slide corrugated tube over the cable Since our charging cable runs in the wheel housing (Fig. 11, p. 124), it must be reliably protected against water and stone chipping. We therefore put it in a metal protective hose with PVC coating (Fig. 8) over a length of about two meters (from the charging socket to the start of the protective aluminum carrier unit, p. 114). Only then do we guide the charging cable through the orange corrugated pipe (internal diameter 23 mm). The rest

Fig. 7: Back of the charging cable - already in the original rubber sleeve from the Volvo tank opening. But still without the protective sleeve that belongs to the charging socket, and also without the protective corrugated tube.

Fig. 10: The charging socket in front of the original Volvo rubber sleeve.

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That’s how it works – 5.2 Wiring the charging socket

The charger delivers up to 2 A on the 12 V line, which can be used to activate various systems, including the charging relays. Pin 4 is grounded by the VCU to allow charging to begin. It is a redundancy for communication via CAN Bus. Pin 7 is connected to ground (pin 1) inside the charger. In contrast to the 12 V supply, a plugged-in cable can be detected with this pin even when the charging station is without power. If this connection is present, the vehicle may no longer be moved, i.e. the engine may no longer rotate. There are many ways to achieve this, the most elegant being a digital input to the VCU. The VCU then switches the inverter into neutral gear. Pin 10 turns on the relays in the vehicle as soon as charging can begin. The charging process is actually controlled via the CAN Bus in the VCU. Pin 1 must therefore be connected to vehicle Ground, pin 2 is routed to the VCU AND to the charging relays. Pins 7, 8 and 9 also go to the VCU. Pin 10 back to the charging relays.

Fig. 11: The charging socket cable is securely fixed in the wheel housing.

This completes the wiring of the charging socket. The only thing missing is the installation behind the tank cap (Fig. 10). This is a bit “tricky” because the space is very tight. We manage it by first positioning the rubber sleeve and charging socket behind the metal panel of the tank opening. Then we put the rubber sleeve over the circular opening and tighten the charging socket. Once that’s done, one last task remains: attaching the charging cable to the wheel housing. The outer diameter of our charging cable has increased significantly due to the protective metal tube. We therefore need three metal clamps with a diameter of at least 28 mm. The clamps are fixed on two threads that also hold the plastic insert in the wheel housing. For the third position (Fig. 11, bottom right) we drill a 4 mm hole in the body and screw on the clamp with an appropriate self-tapping screw. Now our charging cable is not only well protected against external influences, but also securely fastened in the wheel housing.

CHAdeMO In the Volvo 850 electric, we opted for the Type 2 charging connector system because Udo will mainly charge overnight at home using the wall box. Nevertheless, we would like to briefly go into the advantages of the CHAdeMO charging socket. For example, it is easy to integrate into the HV system, and most fast charging stations have the option of charging via CHAdeMO.

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Our donor vehicle even included a CHAdeMO socket with about a meter of HV cable and a short control cable. If we had wanted to use them, we would have first routed the HV cables to the two charging relays, which we would have housed in battery box 1. By the way, suitable relays can be found in the PDM (Power Distribution Module) of the Leaf donor vehicle. The charging currents via CHAdeMO usually reach 125 A. However, there are also variants with 250 A. An empty 24 kWh Leaf battery can be charged with up to 230 A, the 30 kWh variant with 250 A. However, these currents only flow for a few minutes. The charging current is then reduced. There are seven control lines in a CHAdeMO connector (Fig. 12):

CHADEMO

It makes sense to switch a well-hidden emergency stop button between pin 10 and the relays. Some charging stations get stuck in such a way that they no longer release the relays and therefore the charging plug can no longer be pulled out. After pressing the emergency stop, this vicious circle is broken.

1 3 4

1: Ground 2: 12 V 3: Unassigned

4: Vehicle charging allowed 5/6: Charging current +/7: Jumper on 1, plug inserted -> interlock

8 10

Side cutters Soldering iron

MATERIAL Charging socket: Typ 2, 32 A, 3 Phasen (z.B. DUO LD T2 32M 3P) Charging cable: H07RN-F, 5-core, cross-section 2.5 mm², 4.5 meters Contact pin cable: Yellow and red copper wire, cross-section 0.14mm², each 4.5 meters Wiring charging socket and connection to the charger: • Connector: Molex Saber Rcpt Hsg / Socket and Wire Housing 6 Pos. 1pc (Part number: 44441-3006) • Pin: Molex Saber Term F 18-20, 6 pieces (part number 43375-3001) • Connector: Molex CONN RCPT HSG 12POS 5.84MM, 1 piece (Part number: 0194180026) • Pin: Molex MX 150 F 14 - 16 AWG R, 12 pieces (part number 33012-2001) Metal protection tube: With PVC sheathing, outer diameter 21 mm, inner diameter 17 mm, 2 meters (f.ex. Flexa SPR-PVC-AS)

Corrugated pipe: Orange, inner diameter 15 and 23 mm Wago clamp: 1 x 5 positions

8/9: CAN high, CAN low 10: Charging relay ON (switched Ground)

Wire strippers

Metal clamps: M32, diameter 31mm, 3 pieces

7 9

TOOLS

Fig. 12: Connections (PINs) CHAdeMO socket.

Electric solder

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That’s how it works – Chapter 6:

Stability and protection

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6.1 Frame reinforcement and impact protection

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6.2 Splash and stone-chip protection

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That’s how it works – 6.1 Frame reinforcement and impact protection

Torsion- and impact-resistant

Access to service plug TOOLS

Some Volvo models, including the Volvo 850 wagon, are known as “Swedish bricks” because of their boxy but safe design. Rightly so. However, we changed the body structure at the rear. So we have to make up for that.

Angle grinder 180 mm grinding wheel Vice and screw clamps (squared timber for bending the PVC) Allen key, 5 mm

Taking exact measurements

With the stabilizing cross we compensate for cutting out most of the spare wheel well. But installing battery box 1 in the rear requires another safety element. The minimum distance required in Germany (300 mm) from an HV component (box 1) to the end of the vehicle is met. Nevertheless, we decide to install an impact bar (Fig. 2, dimensions, p. 187) in the remainder of the spare wheel well. We attach a bent stainless steel tube (diameter 25 mm) to it. In the event of a rear-end collision, it is intended to divert the forces via the spare wheel well and the frame. Since the sheet metal of the spare wheel well is only 1.5 mm thick and we need to prevent the tube from tearing out in the event of an impact, we weld it onto large brackets. They are screwed together using counterparts on the outer wall of the spare wheel well (Fig. 2).

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Hot-air gun with reduction and welding nozzle (for welding rigid PVC) Multitool with saw for rigid PVC Alternatively: hacksaw

By cutting out large parts of the spare wheel well (p. 44 – 45) we have made it possible to place half of the traction battery capacity in the rear. However, this also reduces the torsional rigidity of the vehicle frame. The installation of battery box 1 does not compensate for this loss. So we have to provide additional frame reinforcement. We achieve this by attaching a stabilizing cross over box 1 (dimensions, p. 159). We cut square and flat iron to size with our angle grinder and have our locksmith weld it. The cross is attached to existing holes in the frame.

The challenge in constructing the stabilizing cross: taking exact measurements. This is made difficult by the fact that the fixing points (top left and right) are each slightly inclined outwards. Our locksmith therefore only “tacks” on the flat irons to the square iron arms in the first step. This allows us to check the accuracy of fit before welding the parts together. And indeed: a round of corrections is necessary. But then the cross sits perfectly (Fig. 1). When taking measurements we had to keep in mind: It must be possible to pull the service plug when the cross is installed (see box on opposite page).

Drilling machine Steel drill 9 mm, 11 mm

For safety reasons we need to separate the service plug located in battery box 1 (p. 48) from the 12-module unit and the pre-charge unit. We attach a regular plastic box (dimensions 200 × 150 × 140 mm) to the service-plug unit. To do this, we cut out most of the bottom of the plastic box, drill two holes (6 mm) in the remaining bottom and fix the plastic box with two Allen keys using the existing threads in the service-plug unit (Fig. 3 and 4).

File

Fig. 3

Fig. 4

To reach the service plug easily, only the trunk cover should have to be lifted. Therefore, we also need a corresponding cut-out in the flame-retardant rigid PVC safety panel (dimensions 565 × 890 mm) that rests on battery box 1 (Fig. 1, top left).

Carpet knife Fig. 1: Due to cutting out most of the spare wheel well, frame rigidity needs to be increased with a stabilizing cross.

MATERIAL Stabilizing cross (dimensions, p. 159) Square iron 25 mm × 25 mm × 2 mm, 2 meters Flat bar 40 mm × 4 mm, total length of the 4 sections approx. 400 mm Hex screws: 3 × M8 × 30 mm (bottom left and right and top left), 2 × M10 × 30 mm (top left and right) Impact bar (Dimensions, p.187) Stainless steel tube, 25 mm diameter, curved, 1 meter Flat iron angle Hex screws: 8 × M8 × 30 – 40mm

Fig. 2: The counterparts of the brackets on the outside of the spare wheel well.

Splash protection engine compartment and underbody

Rigid PVC panels 1000 × 500 mm, black, 2 mm, 5 pieces Welding rod for rigid PVC, 2 packs of 35 pieces each (225 mm/piece) Splash protection engine compartment (dimensions, p. 188) Part 1: Hex screw: 1 × M8 × 25mm Retaining clip Part 2: Flat bar angle, 2 pieces Hex screws: 2 × M8 × 20mm (the second hole in the brackets is attached to the protruding thread of the screws that also hold the support rail, p. 170; 2 × M8 × 40 mm Allen key)

Splash protection underbody (dimensions, p. 189–192) Screws: Attached partly to existing threads/screws, partly using self-tapping screws Service plug (separation from rest of Box 1) Plastic box, dimensions 200 × 150 × 140 mm Screws: 2 × 20 mm Allen key

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That’s how it works – 6.2 Splash and stone-chip protection

Waterproof and impact resistant Though we are definitely approaching the completion of our conversion project, some important work is still to be done. Otherwise, the Volvo would not be roadworthy and fit for everyday use.

Let us start with the engine compartment. So far, our concerns have been focused on where and how the required components can be securely fastened. Now another question needs to be answered: How can the components be protected against splashing water and stone chipping? Well, first of all we attach a protection to the frame from below (Volvo part number 139 7236). However, from the front some components are still exposed to the elements. We have to create a protective device ourselves. That sounds challenging, and it is. However, it gives us the chance to learn a new skill the molding and welding of plastic. As with the stabilizing cross, taking precise measurements is challenging – especially when lying on the garage floor under the car with only a few centimeters of space to the underbody. Since errors happen quickly, it is advisable to first create a mock-up out of cardboard. That’s what Udo did (Fig. 5). In this way, he was able to check his measurements and adjust them at one point or another.

Fig. 5: Mock-up of the splash and stone chip protection behind the front bumper.

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The manufacturing process of the protection begins with the transfer of the dimensions to the rigid PVC panels. Pencils, pens or chalk hardly stick. That’s why Udo used a carpet knife. First, the plastic needs to be cut. We fix a panel with screw clamps on the workbench and equip our multitool with a saw blade (Fig. 6). The tool proves to be the means of choice because the blade goes through the plastic like butter. However, we have to work very concentrated – so that the cuts are really straight and made to measure. A standard hacksaw can also be used to cut the plastic to size, albeit it is a little bit more tiresome.

Two-part unit Our front protection for the engine compartment consists of two parts (Fig. 8, dimensions, p. 188) – both are fixed in two locations on the left and right. For part 1 we can use an existing thread on the driver’s side (M8). On the opposite, we attach the protection to the body using a retaining clip (Fig. 9). Part 2 is attached with angle brackets on the threads of two M8 screws. These screws fix the support rail for the acoustic warning signal, the HV heater and the mini cooler (p. 91) on the frame. The threads of the screws protrude about 20 mm out of the frame (Fig. 10). When part 1 and part 2 are assembled, we fix them in their intended position and mark where both parts must be welded together.

Fig. 8

After cutting, we recommend two things before starting with bending and welding PVC: tutorial videos and two to three trial works. In our view this is important to gain the necessary experience in handling the hot-air gun and PVC. For example, it is annoying if you heat up too much too quickly and the plastic melts away. Or you learn, for example, that edges can be welded more easily from the inside (Fig. 7). Fig. 9

Fig. 6: The rigid PVC panels can be neatly cut with a multitool.

Fig. 7:Hot-air gun with reducing and welding nozzle, exemplary welding seams.

Fig. 10

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Notes Underbody protection On the underbody, we routed the battery control cable and a BMS cable where the fuel lines used to be (p. 116). These cables run in orange corrugated tubes which provide protection. However, we also want to be prepared for events like stones piercing through the corrugated tubes and possibly damaging cables. We therefore cover these HV cables and all other visible HV cables with plastic panels (dimensions, p. 189 –192).

Fig. 11: To protect cables and connectors against moisture and stone chips part 5 bridges the gap between battery box 1 and 2. The plate is attached to Box 1 (right); cable ties are pulled through the pairs of 3 mm holes.

For fastening the total of six panels – examples see Fig. 10 and 11 – we can partly use existing threads on the underbody. We also drill some 3 mm holes and set self-tapping screws. But that’s not enough. We need more rigidity and we need to prevent the plates from “fluttering”. To do this, we rely on overlaps, connecting pieces and retaining clips (Fig. 12):

= Connections Gap engine compartment

Gap between box 2 and carrier unit Carrier unit

Front

BOX 3

BOX 2

BOX 1 Gap between box 1 and box 2

Axle carrier

Battery control cable and BMS cable

Gap to box 2

Fig. 12: Some of the covers on the underbody overlap or are connected to one another.

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That’s how it works – Chapter 7:

Almost there

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7.1 Communications and display information

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7.2 Test drives

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7.3 Appraisal for roadworthiness

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That’s how it works – 7.1 Communications and display information

Analogue and digital The presentation of operating data in the Volvo 850 electric cannot be compared with the touch screens of modern electric vehicles. Still, essential information is provided on the display of a multimedia car radio in the center console.

It wasn’t easy for Udo, but he had to say goodbye to the original Volvo car radio (with tape deck!). Instead, the screen of a WLAN-enabled multimedia radio now lights up in the center console (Fig. 1). Such a radio is required for communication with the VCU. At the same time, thanks to the touch screen, it also fulfills the function of a control element. There are countless variants of multimedia radios. So, we had to pay attention to the functionality, but also to the dimensions and the appropriate mounting frame.

WLAN per cable? The VCU control board from Johannes is supplied with an attached WLAN module and is located at the front of the engine compartment in the metal housing of the previous Fenix controller. Our tests show that the WiFi connection between the VCU and the passenger compartment is not stable. We suspect that the metal housing is the reason for this. It probably shields the signals too much. We drill two 15 mm holes in the housing and line them with felt. But the connection is still unstable. That’s why we replace the lid of the metal housing completely with a plastic cover. To

seal the entire surface, we glue foam rubber that is two millimeters thick to the plastic. But even that doesn’t solve the problem. The shielding – it dawns on us – is more likely the result of the engine compartment acting like a metallic cage, which the WLAN signals have difficulty penetrating. We therefore resort to the good old cable connection. That means: Instead of plugging the WLAN module directly onto the VCU control board, we place it in the passenger compartment in the center console (Fig. 2) and connect it to the VCU with a cable. Fortunately, we can use an opening in the bulkhead to route the cable. It is the same opening in which the water hose for the rear window wiper runs. Lo and behold, the signals arrive reliably in our multimedia radio, which we can now use as a display.

Displays information while driving With the help of Johannes’ software, we have access to the VCU – and thus to all settings and values relating to the operation of the vehicle. This begins with the real-time voltage of each individual module in the traction battery and extends to the maximum temperature in the heating circuit.

When driving, however, the display only shows a few key figures (Fig. 3). The most important are charge level, engine temperature and the voltage of the 12 V battery. In addition, the information on cell voltages and battery performance is useful. For example, if a cell voltage falls below 3.3 volts, it is high time to charge. And the battery performance provides information on how much power the motor consumes, for example when driving at a constant speed. The power limit is calculated by the BMS. It limits the engine power, if the traction battery is almost empty, very cold or very warm. What is missing from the display is a direct indication of the range. This is because the version of the VCU software used does not know the speed and therefore cannot calculate consumption per 100 kilometers. However, the range can be (roughly) derived from the charge level. We outlined the basis on which this happens in the chapter “Basic parameters Volvo 850 electric” (p. 29). That means: 100 percent charge level indicates a range of around 150 km at a speed of 90 km/h in summer, 75 percent represent 110 km and 50 percent mean 75 km. In drive mode, the display of our multimedia radio shows two bars at the top edge of the touchscreen (Fig. 3). The recuperation can be set in three stages via the top bar. The second bar can be used to switch on the heating and regulate the heat output (wow, the 5 kW heater provides heat in no time!). The touchscreen bar thus replaces the heating control element in the center console. The controls there should therefore always be set to “maximum”. Recuperation and heating output can be changed while driving. It goes without saying that the heating must be controllable. But why the recuperation? Well, on the freeway recuperation can be perceived as annoying. Because usually the vehicle should just roll when taking one’s foot off the pedal. It is also safer to switch off recuperation on slippery roads. However, on country roads a moderately strong recuperation makes sense, for example before corners. In the city, on the other hand, strong recuperation is an advantage because one often has to stop.

Display information while charging

Fig. 1: In the Volvo 850 electric, the information provided by the instrument cluster is supplemented by a multimedia radio display.

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Fig. 2: In order to establish a reliable WLAN connection between the VCU and the multimedia radio, we have to place the WLAN module in the passenger compartment – and connect it to the VCU with a cable.

Fig. 3: Display in drive mode (from top): Recuperation bar, heating bar, charge level, battery performance, output limit, motor temperature, cell voltage (min and max), voltage 12 V power supply.

Normally, to start charging one just plugs in the charging cable. The software does the rest. However, the charging process can also be visualized. To do this, the ignition key is inserted and turned to position II. Once the WLAN connection has been established, the standard values just mentioned are shown. But the two bars at the top edge of the display change – from recuperation and heating to charging power and charging limit (state of capacity) (Fig. 4).

Fig. 4: Display during the charging process: Both the charging current (Max. Ladestrom) and the charging limit (Max. SoC) can be set via the bars.

The charging limit gives us the opportunity to adapt the charging process to our driving behavior. For example, if we only need 30 percent of the capacity for normal daily mileage, we can set the charging limit to 80 percent with a clear conscience. Because not always fully charging extends the service life of the traction battery. We only charge up to 100 percent if longer journeys are planned. Reducing the charging power also makes sense if we need to charge via an (older) house installation (230 V Schuko plug in Germany, Type F). In addition to the charging cable limiting charging power to 2.5 kW, the value can be further reduced via the bar. When charging via a wallbox this functionality is not needed.

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That’s how it works – 7.2 Test drives

The moment of truth Before we start our first test drive, we go through everything again: screws, cables, connectors, ground connections, hose clamps. Is everything safe and secure? Then comes the moment of truth.

Just once around the block We start our first test drive. Before that, Udo had of course obtained a short-term license plate from the responsible vehicle registration office so that the Volvo could also be driven on public roads.

Udo continues to turn the ignition key to position III. The drive-mode light comes on; ironically, we use the warning light that previously signaled “Fault in the engine electronics” as our drive-mode indicator (Fig. 5). The Service light goes out after a while. The revolutions counter (top left in Fig. 5) shows around 800 revolutions per minute in drive mode.

We don’t want to overdo it the first time. So we just drive “once around the block” (approx. 10 km), accelerate to a maximum of 70 km/h, also test the reverse gear and the recuperation - and everything runs smoothly so far. When parking, we always apply the handbrake so that the vehicle does not start rolling.

In addition, the cooling water and hydraulic pumps start up, as does the pump that builds up the vacuum for the brake booster. The pump switches off again after around 20 seconds.

When the Volvo is back in the garage, however, an oil stain forms after some time, small but a stain nonetheless. A check shows that we did not fully tighten the drain plug for the transmission oil (which we had to drain and refill during the course of the project) or that the seal is damaged. This is of course annoying. So, we have to drain the transmission oil once more, get a new seal and screw and then refill and screw it on again. As the saying goes: Small cause, great effect.

Udo engages third gear, releases the handbrake and accelerates slightly. And indeed. The car slowly rolls forward. The whirring of the acoustic warning signal can now also be heard. Up to speeds of 25 km/h it is supposed to warn pedestrians that our electric Volvo is approaching.

The second test drive includes a freeway drive where we accelerate the Volvo in third gear up to 120 km/h. The revolutions counter shows an acceptable 4,200 revolutions of the electric motor. We stop briefly, shift into fourth gear and accelerate to 130 km/h at 4,000 rpm. That, too, is a good value.

Then Udo turns the ignition key to position II: Various lights come on in the instrument cluster and after about two seconds it clicks. The pre-charging relay switches. That’s good news. The bad thing is that the indicator light for the ABS system does not switch off, i.e. there is a fault. Udo sits in the driver’s seat, inserts the ignition key and unlocks the steering wheel lock (position I). The radio turns on acoustically and visually (display). First of all, we test important basic functions of the vehicle, such as hazard warning lights, lights and windscreen wipers, in a kind of “pre-flight check”. And indeed: everything still works. So we didn’t disconnect or damage any cables that are important for operating the vehicle and also for the registration of the Volvo.

The reason, it turns out, is a cold solder joint – which is a common occurrence on the Volvo 850 given the age of the vehicle. With the help of a specialist that we researched online, this can be solved in a few days for little money. We send in the ABS control and receive it back repaired. A fault-free ABS system is a prerequisite for the registration of the Volvo. OK. Now, the ABS indicator light also goes out after a few seconds.

Fig. 5

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That’s how it works – 7.3 Appraisal for roadworthines

Acid test The time has come: The Volvo 850 electric has to prove that it is actually roadworthy.

The place of action is the branch of an expert organization (Fig. 6). In Germany, they have the sovereign task of ensuring the road safety of motor vehicles. Specifically, it is TÜV SÜD in Memmingen. Philip presented his Toyota GT 86 there and achieved approval. Udo also chose the tranquil town in the extreme south of Germany, although it is around 300 kilometers from his home and a car transporter had to be rented for the journey. However, Udo wanted to meet an expert experienced in judging conversions. As already explained (p. 24), it is strongly recommended to coordinate the basic concept of a conversion with an automotive expert as early as the planning phase. The same applies to

the final phase of the project. Because now the question is whether the concept has actually been implemented professionally and in accordance with the rules. An important document in this context is the so-called conversion documentation. It describes in pictures and text how the requirements of the TÜV Association publication (p. 24) are met. The automotive expert receives the documentation in advance of an on-site appointment. This allows him to get a concrete impression of the conversion and, if necessary, to ask questions. In this way, some fundamental questions can be clarified in advance. This is primarily in the interest of the person presenting a vehicle. But there is no guarantee that the vehicle will be accepted at the first appointment. Follow-up work and a second appointment were also necessary for Udo.

Fig. 7: The automotive expert not only examines the HV components, but of course also the body and mechanical parts.

A conversion must of course first of all meet all the criteria that are also set for the safety of a combustion vehicle. These checks include lighting and brakes as well as wheel bearings and tires (Fig. 7). With regard to the conversion to an electric car, the expert has a particularly close eye on electrical safety and electromagnetic compatibility on the basis of international standards (UN Regulation No. 10 and No. 100).

In order for potential equalization to work, all HV components must be connected to ground on the vehicle body. Then – should HV components be live due to an insulation fault – the voltage is diverted, thus reducing the electrical hazard for people.

Electrical safety Naturally, electrical safety plays a decisive role in the acceptance of a conversion. At the core there are two measurements – potential equalization and insulation resistance. To what extent do these two measurements contribute to safety?

Fig. 6: Udo’s Volvo waiting to enter the test bench of the expert organization in Memmingen (Allgäu).

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Potential equalization Well, on the one hand, potential equalization is a prerequisite for reliable monitoring of the insulation of the HV components. On the other hand, it reduces the risk of electric shock that

can arise if there is an insulation fault but the system does not switch off automatically.

The potential equalization function is measured via the resistance between the housings of the HV components and the vehicle body. According to the specifications of ECE-R-100, the resistance must be less than 0.1 ohms. A special measuring instrument is required for this. In contrast to normal multimeters, the so-called megaohmmeter can output a test current that roughly corresponds to the voltage of the vehicle. Insulation resistance While the resistance must be very low when measuring the potential equalization, it is the opposite when measuring the insulation resistance. Here, the ECE-R 100 requires a value of more than one megaohm.

In our project, the permanent monitoring of the insulation of the HV system is carried out by the BMS. It permanently monitors the separation of the HV circuits from the vehicle ground. As soon as the insulation resistance falls below a defined threshold, the system switches off. A megaohmmeter is again required to measure the insulation resistance. Here, too, a high test voltage is required when the HV system is switched off. It must be greater than the nominal voltage of the HV system (in our case 380 volts). The measurement thus simulates a live system. It is carried out by a HV positive and negative pole against vehicle ground. When planning a conversion project, it is therefore important to ensure that the HV connections are easily accessible or can be accessed with as little effort as possible. Due to the importance of the measurements, both the potential equalization and the insulation resistance measurement must be carried out by a certified HV specialist. The results are recorded in a corresponding test report.

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Notes

Vibration Further aspects of electrical safety are the protection of the HV components against stone chipping and moisture (p. 130) and against vibration. The latter must be ruled out at all costs so that HV cable connections do not loosen up and become a source of danger. Even if the HV cables in Box 1 are only short between their connections, Udo has given them additional support. To do this, he was able to put a superfluous Leaf part between the negative pole of the 12-module unit (Fig. 9) and the service-plug unit (Fig. 10). On the plus pole, the HV cable is supported by a rubber buffer. It is attached with a cable tie to the relay of the pre-charging unit (p. 97), which is not in use (Fig. 10).

Electromagnetic compatibility UN Regulation No. 10 specifies limit values for electromagnetic compatibility. Depending on the frequency range and measurement method, electric fields must not exceed certain strengths. This is intended to rule out health hazards for the vehicle occupants as well as component malfunctions. A complete EMC test costs around 5,000 euros in Germany. Up until now, it has not been required for conversions as long as EMC evidence for the installed components could be submitted or the expert organization had access to it from its own sources. But in the case of conversion projects in which the traction battery is distributed to several places in the vehicle and wired accordingly, regulations now make an EMC test a precondition for the appraisal procedure. Of course, that would significantly increase the cost of conversions. However, the technical development (more battery power in less space) suggests that in the future more projects will be able to do without the division of the traction battery – especially conversions that – similar to Udo’s Volvo – are mainly used in urban or regional areas for short distances.

Fig. 8: A leaf part serves as a cable support for the HV connection between the negative pole of the 12-module unit and the service-plug unit.

Abb. 9: The HV cable rests on the Leaf part, but is additionally fixed with a cable tie.

Abb. 10

142

143

So geht‘s / Batterieboxen Und sonst?

What else?

144

And what about the cost?

146

Partners to be counted on

148

Tools you can’t do without

150

It’s better with music

152

Epilogue

154

Diagrams and illustrations

156

145

What else? – And what about the cost?

U / N1

Cost2

U / N1

Components Nissan Leaf

Real expenses Yes, the costs! Perhaps the biggest mystery about conversion projects. But we leave the level of “It depends” statements and list expenses based on the example of Udo’s project.

Traction battery

BMS

Cable

Electric motor

HV cable

568

Main contactor

Insulating tape

Cooling circuit water pump

Copper strands (BMS cable)

Service plug

Cable glands

115

Inverter

Cable lugs

Cell connectors

Charging socket (Type 2)

Charging cable (H07RN-F, 2.5 mm2, 5 m)

Connectors

366

Android car radio 10.1

Other components

550

High-voltage heater (Webasto)

120

Hydraulic pump for power steering (TRW)

Corrugated pipe (orange, AD 21 mm, 50 m; AD 28.5 mm, 5 m) Corrugated pipe (black, diverse AD, 100 m)

Cooler (small)

Metal hose with PVC coating (OD 21 mm, 2 m)

Charger (Tesla)

560

Vacuum pump for brake booster (VW)

100

An important influence on the costs is the approach regarding the main components: Second Life or new? Our view: Second Life is cheaper, but the project is likely to take longer.

Water pump heating circuit

Tools also appear in the list. These are tools specifically required for a conversion project. Naturally, the tool costs depend on how well one is equipped before the start of a project.

Tesla Gen 2 charger logic board

1,435 Software

Tesla Gen2 charger firmware

Leaf control board with support

970

Metals/metalwork

2 in Euro / Gross 3 The donor vehicle cost 5,900 euros and was sold again for 1,500 euros after removing the required parts.

146

1,453 Vehicle

500

Engine removal Springs (rear, reinforced)

166

Spacers (rear)

470 1,136

150

1,144

1 U = Used / N = New

4,4003

Adapter plate gearbox and electric motor, spacer rings

195

Aluminum plate (large/small)

Battery boxes (3)

750

Junction box (aluminum box)

Brackets (electric motor, pumps, etc.) N

414

Stabilizing cross

450

Impact protection

300

Rotex coupler (motor/gearbox)

145

Cost2

Other parts

Acoustic warning signal

However, prices vary from country to country, and may have increased since Udo finished his project. Still, we hope that the structure of our overview helps when calculating a project.

U / N1

Display

DC/DC converter (Tesla)

Our overview contains all expenses (in euros) that are directly related to the project – except for the working time, which we have not priced and not included.

Cost2

Tools Crimping pliers

Electrician socket wrenches

Hole saws

Motor crane

100

Multimeter

Hydraulic trolley jack

Angle grinder

Compressor

Vacuum coolant refiller

Hot-air gun

Rubber buffer (engine mounting, junction box)

Cooling water hose (3 m)

Cooling circuit expansion tank

Heating circuit expansion tank

Foam rubber (battery boxes)

PP foil orange (battery box lining)

Hose connectors (cooling/ heating circuit)

Screws, clamps

289

Fuses (40, 30 A)

Fuse 225 A

PVC plates

107 741

Safety/Security Electrician helmet with visor

175

Electrician jacket/trousers

HV gloves

Electrician shoes

110

HV warning notices (stickers)

10 406

Miscellaneous Approval roadworthiness

1,190

Consulting

2,174

Vehicle registration, license plates

200

Volvo service manual

Nissan Leaf manual

TÜV Association publication

Car carrier (rent and gasoline)

750 4,400

TOTAL

18,278

704

2,364

147

What else? – Partners to be counted on

Experienced mechanics Jakob Amann and Nino Troia have accompanied Udo and his Volvos for years. They also ensured road safety for his Volvo 850, which came from Switzerland with several defects. In the project, they not only removed the combustion engine and tank, but also checked everything again at the end of the conversion. Not least because of this, the road approval went without any problems.

Teamwork Voltage specialists

Apart from all-round talents, a conversion project is not for lone wolves. The requirements for knowledge, skills, tools and technologies are too broad. In addition to Philip for the mechanics and Johannes for the software, Udo therefore had a small but excellent network of partners that he could rely on.

Jürgen and Julian Weth, as boss and junior boss of an electrical specialist company, are experts in high-voltage technology. They bought, cut and pressed HV cables from the German manufacturer LAPP for Udo. Important here is the battery-operated hydraulic crimping tool from Klauke as well as the appropriate crimping inserts and cable lugs. www.elektrotechnik-jooss.de

Metal experts Many years of experience, state-of-the-art machines and clear communication make working with Blech & Technik pleasant – and of course the ability of the company to process DXF files. Blech and Technik made the battery boxes, aluminum plates, adapter plates and spacer rings for Udo’s conversion project. The picture shows (from left) employees Markus Heim, Sinan Kupfer and Thomas Binder in front of a powerful laser punching press. www.blechundtechnik.de

148

149

What else? – Tools you can’t do without

Multimeter (Benning)

Crimping pliers (Knipex)

What counts is quality Henry Ford once said: “Quality means doing the right thing when no one is looking.” However, to implement a strict approach to quality, we need the right tools. Well then, let’s look at some of the devices that are important to a quality conversion project.

Crimping is precision work. We would even go one step further and say: It’s a science. Because the crimping profile and crimping pressure must be precisely matched to the connector and cable. This is the only way to create a connection that is both mechanically and electrically reliable over years of usage. But we had to learn that first. After making the unfortunate purchase of a no-name item, we decided on Knipex. You can feel the 130 years of experience of the German manufacturer as soon as you hold the crimping tool (97 52 34) in your hand.

It is of course a “no brainer” that a multimeter is used in a conversion project. We decided on a device from the German company Benning. It measures, for example, DC voltages up to 1000 V and has an acoustic continuity tester. The German brand fits well to the topic of e-mobility, because in addition to testing and measuring devices, they also develop and manufacture wall boxes and charging stations.

Cable splicing connectors (Wago)

It is not surprising: An electric vehicle contains even more cables than a car with an internal combustion engine. Secure connections can be made using original or aftermarket connectors. WAGO splicing connectors are also a reliable solution that can be implemented quickly.

Angle grinder (Fein)

Insulated hand tools (Wiha)

Safety must come first in a conversion project. For this reason, only insulated screwdrivers and hexagon socket wrenches must be used, for example when dismantling the Leaf traction battery. We relied on the durable and VDE-tested hand tools from Wiha. The German family business has been a partner to the electrical and automotive industries for many years and has recently expanded its range of tools for e-mobility.

150

In a conversion project their is definitely a need for a powerful angel grinder. We bought a 2500 watt machine with a 180 mm disc from Fein. And it was a good decision, because the machine cuts sheet metal and iron (almost) like butter. Fein is a traditional German brand. Incidentally, its founder Emil Fein is the inventor of the electric hand drill. Their machines are designed for tough applications in industry and trade. You will even notice that as a non-commercial user.

151

What else? – It’s better with music

Rock’n’roll sure helps me through It may seem strange, but music is a succsess factor in a conversion project. Because it relaxes and puts you in a good mood – and it can motivate and help you through difficult project phases.

Whether digitally on a smart phone or via radio, CD or a portable device – everyone may enjoy music as they wish. There is no need to install a hi-fi audio system in the garage. In Udo’s opinion, however, a mini radio is not enough either. That’s why he got himself a 35-year-old ghetto blaster, which not only delivers good sound, but also includes visualizing level control in green and red colors. He obtained the device from Christian, whose hobby is to refurbish vintage devices – in the spirit of the Second Life idea. So, thank you, Christian! Good job. The sound is perfect, and the light effects are is impressive. We usually notice that music touches us on a very personal level when it’s playing in the background and we suddenly have the feeling: Wow, that’s cool. Usually individual riffs, catchy tunes, but also particular lines of the lyrics burn into the brain.

Monster Magnet, Dig that hole I, I can‘t sleep at night cause that‘s the only time when I feel truly free. And I just want to drive my car. I don‘t know where I‘m going but at least I ain‘t standing still.

Rainbow, Temple of the King One day in the year of the fox came a time remembered well. When the strong young man of the rising sun heard the tolling of the great black bell.

Nevertheless, music is a very individual experience. We perceive every melody and every line of the lyrics in the context of our own experiences. For Udo, some songs played a special role in his conversion project: • If Udo experienced some doubts creeping in whether the Second Life approach and thus the climate aspect of his project are really that important, he got himself back on track with the Stranglers “Something better change”.

Stranglers, Something better change Something‘s happening and it‘s happening right now. Ain‘t got time to wait. I said: Something better change.

• If things didn’t go well with the project and he ended up in a dead end at one point, Foghat’s “Stone Blue” helped him on his feet. • When he needed to work hard, a ballad like Rainbow’s “Temple of the King” was just what he needed.

Foghat, Stone blue

• And when it was necessary to motivate himself to spend the evening in the cold garage in winter, he turned on the heat with Monster Magnet.

Turn up the radio higher and higher, rock and roll music set my ears on fire. When I was stone blue, rock and roll sure helped me through.

If you would like to tune in to Udo’s playlist, listen to it on Spotify (EV Converter’s Songs of Pleasure and Pain). Here is the link: https://tinyurl.com/35EVconverterSongs

152

153

What else? – Epilogue

The big picture We didn’t write a novel. Nevertheless, we think a closing epilogue is appropriate. Because despite our focus on the details of a conversion project, we must not lose sight of the big picture.

Due to our deep dive approach in this book, we have covered almost every single step in a conversion project. Why is this important? Sure, Volvo 850 owners should ideally be able to use the book as a blueprint for their own project. This alone is worth the effort, as around 717,000 Volvo 850s were produced between 1993 and 1997. If you include all model versions that can be traced back to the Volvo 850 (e.g. the first V70 generation), the number increases to a total of 1,360,522 vehicles.1 However, beyond the “how it works” aspect, there is another motivation: We wanted to document a conversion project in all its complexity so that all interested parties can think about how the process can be simplified, standardized and therefore made quicker and more cost-effective. This process will apply not only to Volvos, but also to other brands and models. As the details may differ, the essential conversion process is independent of the original vehicle. Our goal is to inspire people, so they join in the action and become campaigners for the topic of electric conversion. This way, there is a chance that conversions can make a relevant contribution to conserving limited resources and to climate-friendly mobility. If the number of conversions grows and previously deployed resources continue to be used, this is a win for all of us. It is true that conversions cannot stop climate change. But combined with other (small) steps and initiatives, they can be more than a drop in the bucket. By fellow campaigners, we mean “car guys” in the broadest sense. And there are more than enough of them around the world. Millions see their vehicle not only as a means of transportation, but also as a cultural asset, technical fascination or as an investment. And thousands of real and self-proclaimed automotive experts help with maintenance, repairs and tuning online and on site in countless garages. We want to encourage

and mobilize this community: make your next project an electrical conversion and document it for others to follow in your path! On the other hand, we are convinced that conversions of used cars are also an issue for original equipment manufacturers (OEM) and their suppliers. And indeed, the idea seems to be gaining ground that – if a company is serious about sustainability, resource conservation and the circular economy – it should not only look at the process of new car production. In any case, there are signs that some car manufacturers have understood. A pioneer is Renault. The company has converted its traditional factory in Flins into a re-factory. 2 It is now described as “the first European center for circular economy in the mobility sector”. Other projects, for example, are about developing conversion kits for existing Renault Master delivery vehicles and for iconic vintage models like the Renault 4 and Renault 5.3 And Stellantis, the owner of Renault, announced that it will establish a Circular Economy Business Unit based on its 4R strategy: Remanufacture, Repair, Reuse and Recycle.4 The US manufacturers Ford and General Motors as well as Toyota have also launched or announced solutions for converting their own existing vehicles.5 And what about the German OEMs? There are electric conversion solutions for iconic models such as the VW Van (Bulli), the VW Beetle and the Opel Manta.6 But so far these are individual projects.

This could even involve comparatively young combustion engine models (e.g. registered since 2015) that still have a long car life ahead of them. A conversion of these vehicles may well be a challenge from a (software) technical point of view. But it should be feasible for the engineers at the OEMs and their suppliers as long as they really set their focus on it. However, popular classic cars could also become the focus of conversions where individual owners want to be climate-neutral on the road. We are convinced that there would be a market for both. No doubt, interest in conversions is increasing around the world. This has to do with the fact that more and more people are consuming more responsibly, and for good reasons. Because happiness and quality of life do not depend on always owning the latest product with the latest but often hardly used features. On the one hand, a new modesty and a return to reliable, but not “over-engineered” products is finding more followers. On the other hand, the understanding of innovation is also changing. Behind the new concept of “frugal innovation” is an attitude that takes the threat to our livelihoods seriously and wants to change something in the individual lifestyle. In this respect, conversions of existing vehicles are an example of such innovation. In addition to individual motorists and manufacturers, the state also has a role to play, namely that of financial support. The German state has fulfilled this role well – as far as new electric cars are concerned. So far, the promotion of conversions has been limited to trucks.7 Practically all other countries are acting with similar restraint. To our knowledge, as of July 2023 only France supports the conversion of ICE passenger cars

to electric with up to 5,000 euros each depending on the income of the converter and some other conditions.8 Also, the US state of California has started a legislative process to promote conversions to electric with 2,000 dollars each.9 In Colorado, the cost of a conversion can be tax deductible and reduce the tax burden by up to 2,500 dollars.10 “There is no doubt that we are at the dawn of an electric conversion era.” 11 This quote is from Aymeric Libeau, head of Transition One. Starting in 2023, the French start-up plans to convert 100,000 small cars within five years for 5,000 euros each with new component kits. With his ambitions, Libeau represents committed people from all over the world. This can be seen in numerous media reports and videos in which private individuals and workshops report on their conversions. Of particular interest are contributions whose focus goes beyond individual projects – for example, students in Calgary, Canada, contributing to the development of the conversion community with concepts that are repeatable and suitable for different makes and models.12 The realization that it makes sense to convert as many suitable existing vehicles as possible during the transformation phase of mobility is increasingly cited as a motivation. We need many approaches and solutions on how we can use limited resources more intelligently to slow down climate change at least a little. So although we can be optimistic when it comes to electrical conversions, there is still a long way to go. This book would like to help ensure that Aymeric Libeau’s prognosis will really come true.

1 Volvo Car Switzerland AG, Press release 191851, June 7, 2016 (German). 2 Renault press release, Nov. 25, 2020: Groupe Renault creates the first European factory dedicated to the circular economy of mobility in Flins. 3 Renault press release, July 18, 2022: Renault Group and Phoenix Mobility launch the electric retrofit of commercial vehicles at the Re-Factory in Flins; Renault press release, Jan 25, 2023: Renault teams up with R-FIT to launch in France electric retrofit kits for its iconic vintage models.

In our view OEMs would greatly underline the seriousness of their sustainability efforts if they just take – like Renault – some volume models and plan how they can be converted: in their own plants (see Renault/Flins) or in dealerships and independent workshops, and ideally using second-hand components from the respective manufacturer.

4 Stellantis press release, Oct 11, 2022: Stellantis fosters circular economy ambitions. 5 auto motor sport, Nov 8, 2021 (German); Detroit Free Press, July 20, 2022: Chevrolet to offer kit to convert gasoline classic cars into EVs; Time.com, Jan 13 2023: Don’t replace your car, replace its engine, Toyota says, pushing sustainability shift. 6 Süddeutsche Zeitung, Apr 17, 2020: Bulli under power (German); Golem.de, May 19, 2021: Electric Manta with gear shift and mini battery (German). 7 Federal Ministry for Digital Affairs and Transport, Press release 72/2022, Sept 22, 2022 (German). 8 MIT Technology Review, 8-2022 9 California Assembly Bill AB 2350: Vehicular air pollution: Zero-Emission Aftermarket Conversion Project; passed as California Senate Bill SB 301, May 30, 2023.. 10 Colorado Department of Revenue, FYI Income 69, July 2021. 11 Brussels Times, July 17, 2022.

154

12 CTV News, May 25, 2022: University of Calgary students turning vintage car into electric vehicle.

155

Battery Boxes

Battery Box 1 Inner dimensions

Battery Box 1

– Inner dimensions 157 Cable entry points 157 Inner dimensions bottom 158 Inner dimensions backside 158 Stabilizing cross 159

Battery Box 2+3 – Inner dimensions

890 230 565

– Cable entry points (lid)

160

Battery Box 3

– Cable entry points (lid) Inner dimensions and boreholes

161 161

20 40

160

Battery Box 2

80 175

(mm) 250

Battery Box 1 Cable entry points 25

(mm)

25 250 125

890

BATTERY CONTROL CABLE Ø 35 mm M6

125

HV INVERTER Ø 32 mm

BMS BOX 3 Ø 20 mm

445

BMS BMS BOX 2 BOX 2 Ø 20 mm Ø 16 mm

25 M6

BOX 2 Ø 32 mm

156

157

158 25

110

70 50

210

250 25

890

10 101,8

97,8

98,1

18°

25 25

60 10

Flat bar lower right

110

155

( REAR)

Battery Box 1

= contact surface square iron TR = opening service plug Dimensions square iron to beginning of flat bars

102,0

Inner dimensions backside

130 100

310

18°

MODULES

565

100

200

270

BJB Flat bar top right (18° inclined)

TSE

40 50

Square iron 25 mm × 25 mm × 1,5 mm Flat bar: 4 mm Holes: 11 mm

225 185

101,3

165

295

91,1

260

150

180 170 110

98,5

365

BMS

(mm) 890

99,0

(mm)

( FRONT )

(18° inclined)

(view from above)

Length lower edge square iron

Inner dimensions bottom

Length top edge square iron

Battery Box 1 Battery Box 1

Stabilizing cross

(mm)

159

Battery Box 3 Kabelausgänge

Battery Box 2+3

batteriebox 3 Cable entry points (lid)

Inner dimensions

Boreholes bohrungen HV-cables: 32 mm hv: 30 mm BMS-cable: 20 mm bms: 20 mm 45

85 175

350

470

125

115

740

(mm)

735

170

740

(mm)

Battery Box 3

Lid outer dimensions

175

Inner dimensions and boreholes (side wall) (mm)

Battery Box 2 Cable entry points (lid)

CONNECTOR 4 POS.

Boreholes HV-cables: 32 mm BMS-cables: 20 mm, 16 mm

BOX 1

BOX 2

CONNECTOR 25 POS.

75 735

310

145 40

BMS

350

40 11

60 9

175 115

130

310

135

430

100

740 (mm)

160

161

Brackets

Drive Shaft

Flat steel bar: 4 mm Holes: 9, 11, 13 mm 20

Drive Shaft

163

Battery Box 1

163

Battery Box 2

164

Battery Box 3 Rear (firewall)

164

Battery Box 3 Front (frame)

165

Electric Motor Bottom (2 pcs.)

165

Electric Motor Front 1 (frame)

166

Electric Motor Front 2 (frame, on rubber buffer)

166

Acceleration Potentiometer

167

Transmission (front)

167

Heater (front view)

168

Heater (rear and side view)

168

Hydraulic Pump

169

Radiator

169

Support Rail (acoustic warning signal, heater, cooler)

170

Vacuum Pump

170

Water Pump (heating circuit)

171

Water Pump (cooling circuit)

171

M10

M10 140

Batteriebox 1 Flacheisen: 4 mm Bohrungen: 11 mm

20 200

M12 15

(mm)

Battery Box 1

120

Flat steel bar: 4 mm Holes: 11 mm

Batteriebox 1 Flacheisen: 4 mm Bohrungen: 11 mm

155

120 120 20 155

895 Inner dimension

(mm) 155

162

120

(mm)

163

Battery Box 2

Battery Box 3

Flat steel bar: 6 mm Holes: 11 mm

Front (frame)

205

180 130

Standard angle bracket: 70 x 70 x 55 mm Flat steel bar: 2 mm Holes: 9, 11 mm

BOX 3

210

180

200

70 15

(mm)

200

730

FRAME

130

55 (mm)

Electric Motor

Battery Box 3

Bottom (2 pcs.)

Rear (firewall) Flat steel bar: 3 mm Holes: 11 mm

Flat steel bar: 5 mm Holes: 11 mm

15° 50

150

105

135 195 625

(mm) (mm)

164

165

Electric Motor

Acceleration Potentiometer

25 10

Front 1 (frame) 20

Flat steel bar: 4 mm Holes: 13 mm

Flat steel bar: 4 mm Hole: 9 mm

145

160

12,5

15 240

160

100

155

(mm)

(mm) 12,5

Electric Motor

Transmission

Front 2 (frame, on rubber buffer)

Front (frame, on rubber buffer)

Flat steel bar: 4 mm Holes: 11 mm

12,5

Flat steel bar: 3 mm Holes: 11 mm

140

100

(mm)

166

12,5 25

167

Hydraulic Pump

Heater

186

Front view Flat steel bar: 3 mm Holes: 7 mm

Flat steel bar: 3 mm Holes: 11 mm

70 25 12,5

15 12,5 30

80 120 25 65

(mm)

167

Radiator

Heater

Back and side view Flat steel bar: 3 mm Holes: 7 mm

Flat steel bar: 3 mm Holes: 6 mm

67,5

210 75

67,5

120

PLATE (BACK)

SIDE VIEW

50 40

(mm)

15 70

168

170

12,5

169

Support Rail

Water Pump

For acoustic warning signal, heater, cooler

For heating circuit

L-bracket profile: 50 x 50 x 3 mm Holes: 11, 9, 7 mm Aluminum

Flat steel bar: 2 mm Holes: 9 mm, 6 mm

60 M5 10

ACOUSTIC WARNING SIGNAL 170

HV HEATER

40 10

COOLER

785

190

110

185

(mm) 15 25

(mm)

Water Pump

Vacuum Pump

For cooling circuit

Flat steel bar: 3 mm Holes: 9 mm

20 35

160

35 35 35

50 20°

105 25 25

(mm)

(mm) 25

170

171

Cable Routings

12 Volt Battery MB

12 Volt Battery

173

Acoustic Warning Signal

173

Battery Control Cable

174

BMS Cables

174

CAN Bus System DC/DC Converter

175

Acceleration Potentiometer

176

Transmission

176

Heater

177

High-Voltage Cables

177

Hydraulic Pump

178

Junction Box

178

Cable Box (engine compartment)

179

Components (engine compartment)

180

Type 2 Charging Socket

180

Charger/Charging Cable

181

Ground Connections

181

Vacuum Pump

182

Water Pumps

182

Converter/Motor

183

Ignition

183

CH CB DC/DC

REL

J/B

R R

175

BAT

OEL

HVH

WAGO 1

FUSE 10A REL HVH (R) MB (R) CH (VO) (R)

Acoustic Warning Signal

VCU

172

CONNECTOR 2 POS: (AMP SUPERSEAL) VCU AW A36 Y- R SB A21 BL-Y Y

173

Battery Control Cable

Can Bus System WAGO CLAMP

Contact assignment ( Box 1 ) 12 V (VO)

CAN LOW (GN)

PRE-CHARGE (BN)

CAN HIGH (OR)

4, 11, 14, 17 IGNITION (R)

GN-GR

VCU (A33)

GN-SB

VCU (A32)

BMS

CV GN

CAN BUS PART A

6, 7, 8 GROUND (SB) VIA CABLE LUG

CAN BUS PART B

B10

NOT ASSIGNED

CHARGE (W)

CAN BUS PART C

CH (B-CONNECTOR)

VCU

CV BL

DC/DC

CONTACTOR (GR)

BMS Cables Battery Control Cable: Box 1 CB / CH 4600 mm

DC/DC Converter

MOTOR COMPARTMENT

PASSENGER COMPARTMENT

TRUNK

CONNECTOR 12 POS.

BMS Cable (4 Pos. & 32 Pos.): Box 1 Box 2 700 mm

10 11 12

R CB DC/DC

OR J/B

BMS Cable (24 POS.): Box 1 Box 3 4600 mm

R ( HW-EN )

+ BMS

BL DCSW+

CAN BUS PART C CONNECTOR 2 POS.

BOX 3

174

BOX 2

BOX 1

( ORIGINAL TESLA DC / DC CONVERTER )

175

Acceleration Potentiometer

Heater

E.g.: Bosch 24435990H

Webasto HVH50

J/B GAS

VCU

CONNECTOR 3 POS: (AMP SUPERSEAL)

BAT

CONNECTOR 8 POS

VCU GASPOTI A15 VO P A16 OR-W W A18 BN-SB BN

Transmission

1 2 3 4 5 6 7 8 + 12V BAT

HVH

CONNECTOR 2 POS ORIGINAL HARNESS WEBASTO HVH50

GND

A9 VCU 1J0973714 (VW)

(TE Conn. HVA280 A-KEY )

High Voltage Cables Cable Lengths:

GND

See Volvo Service Manual Cars Section 3 (39) Wiring diagrams 850 (1993) P. 17, Connector 24 /15 (14 Pos)

176

PCU:

370 mm

M12

SP:

320 mm

M13:

700 mm

M18

M19:

4670 mm

M24

J/B:

1040 mm

PCU

J/B:

4050 mm

MOTOR COMPARTMENT

M24

TRUNK

M19

–

SPEED SENSOR CONNECTOR 2 POS BN-Y, GN-Y

PASSENGER COMPARTMENT

M1 + – M18 PCU

VCU

TRA

J/B

– +

REVERSE LIGHT CONNECTOR 2 POS BL-GR, B

M12 –

+ M13

BOX 3

BOX 2

BOX 1

177

IGN

VO OR R

GND

RECTIFIER DIODE

VO BN GN OR R W GR

Engine compartment BATTERY CONTROL CABLE

For Power Steering, e.g.: TRW Gen2, JER 100

BAT

Cable Box

DC/DC

Hydraulic Pump

BL-W

IGN R

GR-OR (A38)

R VCU

BAT

FUSE 80A

OEL

OEL BL-W

GND BN

CHARGE

Junction Box

WP1 WP2 A2

CONNECTOR 3 POS: SB IGN BL-W CB (DCSW+) BN-W NOT ASS.

START

30A

+(3)

HVH BOX 3 (HV)

VCU P-SB A17 CH

CAN BUS PART A BL CV GN

FUSE 225A

FUSE 40A

CAN BUS PART C BL CV GN

- (3)

178

GN-R STARTER

FUSE

CH R

J/B

VCU A23 GR-SB

DC/DC

VCU A32 GN-SB A33 GN-GR

BOX 3

BOX 1 HV

DC / DC DC / DC +

VCU OR-GR A38

VCU VO A2

DCSW+

BOX 1 HV

HVH (HV)

179

Components

Charger / Charging Cable

Engine compartment CHC

Y-GN

NOT ASSIGNED RES

RES

GND CONNECTOR 6 POS

DC (OUT) AC (IN)

J/B CH

IGN

REL

BOX 3

J/B

DC/DC

VCU

MOT

TRA

CONNECTOR 6 POS

VAC

GAS

WP2

BAT

CH B - CONNECTOR 12 POS

CHARGE (R) 12V SUPPLY

WP1 AW

HVH

SB 1

CP (R) CHARGING CABLE CAN BUS PART B ( HI, BL ) 1

W 3

BL BN 4 5

BL 6 WAGO

+ 12V

OEL

GND (SB)

CHC

CAN BUS PART B ( LO, GN )PP (Y) CHARGING CABLE

Type 2 Charging Socket

Ground Connections

Connections (front view)

Engine compartment PE

32 A, 3-Phase PP (Y)

CP (R)

(LONG TERMINAL)

(SHORT TERMINAL) GND DC/DC (GROUND STRAP)

CV (SB) REL (SB) CHC (Y-GN)

GND

N MOT (Y-SB)

GND

BAT (BL) OEL (BN) WP (Y) VOLVO (ORIGINAL HARNESS, 8x)

GND

W GND

180

BL 2

CH(SB) HVH (SB) MOT (GR) VOLVO (ORIGINAL HARNESS, 3x)

GND

TRA (BL) CH (GROUND STRAP) MB (BN)

181

Vacuum Pump

Converter/Motor

Brake Booster

Excluding Can Bus

e. g. Pump Hella 8E0927317H , Sensor Audi/VW 036906051G SENSOR CONNECTOR 4 POS: 1J0973704 (VW) VCU VAC A4 W SB A15 VO SB A18 BN-SB SB A15 VO SB NOT ASS. BN

IGN

GN CV

PUMP CONNECTOR 2 POS. 1J0973722 (VW)

VAC

BN-SB

VCU

VCU VAC A10 GR R GR A27 GN SB R

GR GN

SOLDERED AND WRAPPED WITH SHRINK TUBING OR AMP SUPERSEAL 2 POS.

Water Pumps

MOT

Y-SB

Original Nissan Leaf Harness Assembly EGI Part No. 24011-3NF1A (from donor car)

GND

Ignition

For cooling (WP 1) and heating (WP 2) IGN

WAGO 5 POS. 1

OEL (SB)

CHARGE (R)

IC R R WAGO CB

GN R

FUSE 10A

WP2

BN WP1

+ HEATING

Y GND

REL

COOLING

DCSW +

IGN

SB OEL

BAT

12V RELAY (originally Pos 86 Bosch ign. coil) (W) (R)

RELAY (WITH30A FUSE)

CV (GN)

NOT ASSIGNED BL

W (fromWAGO)

87 86

87A

GND

+ 12 V (10 A)

182

183

Cooling and heating Heating Circuit

Cooling Circuit Ohne Can-Bus-System 1. WP1 2. DC/DC 3. CH 4. CV 5. MOT 6. CO

1. WP2 2. HVH 3. Heater (cold)

DC/DC (+RES) CH CV (+RES) MOT CO WP1

HVH Heater (hot) (+RES) WP2

HEAT EXCHANGER

RES

3 RES

WP2

DC/DC

J/B

2 1

CV 4 1

MOT

HVH

5 6

WP1

184

185

Impact, Splash and Stone-chip Protection

Impact Protection (rear)

187

Splash Guard (engine compartment)

188

Stone-chip Protection (underbody)

189

Impact Protection

Stainless steel tube: 25 mm x 1,5 mm (welded to bracket) Flatbar: 4 mm Holes: Rear 9 mm

Box 1 545 ~70

Spare wheel well Bracket

Bracket Outside

Inside 90

4 10

60 10 15 10

186

(mm)

187

Splash Guard

Stone-chip Protection

Engine compartment

Underbody (overview)

Steinschlagschutz Unterboden Übersicht (schematisch)

Holes: 9 mm = Cuts

Material: Hart-PVC-Platten, schwarz (2 mm) Material: Rigid PVC-plates, black (2 mm)

40 70

10 10

BOX 3

BOX 3 10

Part 1

1210

115

30 1210

200 65

115 75

Position part 2

40 30

210

155 260

40 260

720

Part 2

125 75

40 30 40 40

5 5

40 30

5 155

260

75 200

Position part 2 155

125 200

720

Position part 2

5 210

1210

210

125

115 75

40 40

720

1020 150

Part 2

720

150

720

6 6

35 20

150

1020 150

150

1020

Part 2

6 75

210

Part 1

BOX 2 5

Part 130

BOX 1 1 BOX BOX 1 BOX 1

BOX 2

150

210 35 150 210 35 210

188

150

(mm)

189

Stone-chip Protection

Underbody

Part 3 Holes: 9 mm, Part 3 4mm

Part 1

= Clamps (attached to body) Holes: 9 mm, 4mm

Holes: 9 mm, 4 mm

= Clamps (attached to body)

250 60 25

425

285

(mm)

425

105

170

580

150

310 310

Part 2

20 15

Holes: 9 mm, 4 mm

20 15 20

35 20 17

70 40

215

110

15 15

Part 4 Holes: 9 mm Part 4

165

20 80

150

Holes: 9 mm

250

80 80

125 315

347 175

540 100

20 17

(mm)

20 20

220

170

220

170

465 1005 425 425

190

191

Stone-chip Protection

Notes

Underbody

Part 5

Holes: 11 mm, 7 mm

150 40

40 43

100 11 mm

110

30 150 400

400 455 7 mm

(mm)

Part 6

Holes: 9 mm 15

120 80

160

192

193

Connectors

Second-Life Components Used electric, hybrid and high-voltage components for conversion projects

COMPONENT

CONNECTOR

POS.

TERMINAL

HOUSING

TERMINAL

QTY. CONNECTOR/ HOUSING

BMS CABLE BOX 2

1473672-1

2005154-1

1612035-1

1376109-1

2 each

TE Conn.

1318747-1

1123343-1

1473799-1

1376109-1

2 each

TE Conn.

MANUFACTURER

COMMENTS

1318917-1

1123343-1

1379681-1

2005154-1

2 each

TE Conn.

DC/DC

0334721301

033012-2001

Molex

MG655776

KET

1J0973714

HVA280 A-Key

TE Conn.

44441-3006

43375-3001

Molex

19418-0026

33012-2001

Molex

B-Connector

1J0973704

Connector Sensor

1J0973722

Connector Pump

VAC

Original Harness

Components

Adjustments

Sources

BMW i3

2013-2017

Motor Inverter

None Board replacement

openinverter.org/shop

Chevrolet/Opel

2012-2016

Charger Inverter DC/DC converter Heating

External control unit Board replacement None External control unit

evbmw.com

Lexus GS450h

2005-2011

Hybrid transmission Inverter

None External control unit

evbmw.com

Mitsubishi Outlander

2015-2022

Motor Inverter Charger DC/DC converter Heating

None External control unit External control unit External control unit External control unit

evbmw.com

Nissan Leaf

2014-2017

Engine Inverter Traction battery BMS PDM (Charger) PDM (DC/DC converter) AC compressor

None Board replacement None CAN programming CAN programming CAN programming LIN programming

openinverter.org/shop

Tesla Model S/X

2012-2021

Drive unit Charger DC/DC converter Drive BMS

Board replacement Board replacement None None CAN programming

openinverter.org/shop evbmw.com

Toyota Prius Gen2

2003-2009

Hybrid transmission Inverter DC/DC converter

None Exernal control unit None

openinverter.org/shop

Transmission replaces the standard transmission of the vehicle to be converted.

Toyota Prius Gen3

2009-2016

Hybrid transmission Inverter DC/DC converter

None Board replacement None

evbmw.com

Control also possible without board replacement with external control unit.

VW e-Golf, e-up, e-tron

2017-2022

Chargers

External control unit

evbmw.com

Webasto

2020

High-voltage heating

None

Original Harness

For the battery control cable, inverter, electric motor, water pump/cooling circuit connectors from the Nissan Leaf donor vehicle were used; other connections are made via WAGO terminals (cable box, +12 V battery, ignition) and AMP Superseal connectors (acoustic warning signal, gas potentiometer, hydraulic pump). The water pump/heating circuit came with the necessary connector. We continued to use the Volvo connectors for the gearbox and some ground connections.

194

Year(s)

25 Pos. used

BMS CABLE BOX 3

HVH

Make/Model

Notes

Inverter can also be operated with CAN programming without replacing the circuit board. However, maximum power is limited to 80 kW.

The overview is based on projects on openinverter.org. If you know other used components that have already been used in ev conversions, we look forward to your input. You can reach us at feedback@electrifyyourride. info.

195

Abbreviations COLOR CODES CABLE

ABBREVIATIONS

BL BN GN GR OR P R SB VO W Y

AW = Acoustic Warning Signal BAT = 12 Volt Battery BJB = Battery Junction Box (Nissan) BMS = Battery Management System CAN Bus = CAN Bus CH = Charger CHC = Charging Cable CO = Cooler CV = Converter DC/DC = DC/DC-Converter EV = Electric Vehicle GAS = Gaspoti GND = Ground HVH = High Voltage Heating IC = Ignition Coil ICE = Internal Combustion Engine IGN = Ignition J/B = Junction Box K = Instrument Cluster LBC = Lithium Battery Controller (Nissan) M = Module MB = Battery Control Cable MOT = Electric Motor OEL = Hydraulic oil pump power steering PCU = Precharge Unit PL = Adapterplate SP = Service Plug TRA = Transmission VAC = Vacuum Pump Brake Booster VCU = Vehicle Control Unit WP = Waterpump

196

= = = = = = = = = = =

Blue Brown Green Grey Orange Pink Red Black Violet White Yellow

Notes

197

Your conversion project. Let’s go! If after reading this guidebook you are passionate about EV conversions, then your first steps might look like this....

Convince better half

Set budget

Select vehicle

Invest in professional tools

Create plan

Document right from the start If you want to document your project for others to follow in your shoes, please think of high-resolution and well-lit images right from the start. And make notes about how you went about it and what was special about your car.

198

About Deep Dive EV Conversion There are a few things in life we all should experience or do at least once. In our view the conversion of a gasoline car to electric belongs in this category – simply because individual mobility is so important to millions of people all over the world. An EV conversion also is a reasonable, even necessary project in view of climate change and resource scarcity. And finally, with all due caution when handling high-voltage technology, it’s a lot of fun. Using the example of a Volvo 850, we provide the necessary background knowledge and guide you through the most important steps with the help of 250 photos and diagrams. So, if you are thinking about giving your “old” car a second life, then our guidebook helps you make a well-founded decision on such a project.

Authors Johannes Hübner Johannes is an engineer and the initiator of the OpenInverter platform. All software questions concerning EV conversions are discussed there. He has thus contributed to numerous conversions worldwide and has himself already carried out two.

Dr. Udo Kessler A good starting point for protecting our planet is the private car. Udo is convinced that the potential of EV conversions is great – but still needs to be developed. That is what the managing director of the agency Signum is advocating.

Philip Schuster With his Weltreisewerkstatt Philip is not only an expert in the vehicles needed to travel around the world, but also in EV conversions. He has used his knowledge of mechanics and electronics to convert a Toyota GT86. 9 783982 506319

39,90 Euro

www.deepdiveevconversion.com www.electrifyyourride.info www.openinverter.org