2 minute read
Today’s battery requirements
from Auto Service Professional - June 2020
by EndeavorBusinessMedia-VehicleRepairGroup
Figure 2: Breakdown of a battery voltage waveform. 2015 Chevy Colorado 3.6L V6 battery voltage before, during and after cranking.
PHOTO COURTESY SOUTHEAST MOBILE TECH
PHOTO COURTESY SOUTHEAST MOBILE TECH
Figure 3: Battery cranking voltage using the ATS Escope Elite4. 2015 Chevy Colorado 3.6L V6 compression test.
PHOTO COURTESY SOUTHEAST MOBILE TECH
Figure 4: Battery cranking voltage up close using the ATS Escope Elite4. 2015 Chevy Colorado 3.6L V6, low volts on initial cranking.
on this vehicle (see Figure 3) I noticed that when I first started cranking the engine the voltage at the starter when engaging seemed a bit low. As you can see the voltage began ramping up as the starter started spinning. Another equally important thing to look at on this screen shot is once the starter was spinning fully, the voltage started dropping. Figure 4 shows a zoomed in cranking shot of the initial starter engagement.
There are many different ways you can sufficiently test the vehicle’s battery. The use of an electrical system tester is a very reliable and accurate way of testing not only the battery but the starter and charging systems as well (see Figure 5).
Keep in mind that the battery is what you need to start with first. Without a sufficient battery, testing the starter and alternator will give you inaccu36
Figure 5: Snap-on electrical system testing diagnostic tool.
rate results. For example, when testing a starter, an undercharged battery will drive up the cranking requirements of a starter which will possibly show an excessive amperage. The starter will draw all the available current from the battery due to the fact that the reserve capacity is low. And that will make the starter work harder than it should.
When it comes to your customers you always want to watch for problems that can crop up at any time. Performing a welfare check on their electrical system can prevent a possible failure in the future. Giving the customer an electrical print-out will give them the peace of mind that you are looking out for them. After all, having repeat customers is what it’s all about. ■
Edwin Hazzard owns South East Mobile Tech in Charleston, S.C., which is a mobile diagnostic and programming service providing technical service to many automotive and body repair shops. He has 37 years’ experience in the automotive industry. He currently is an automotive trainer, a board member of TST (Technician Service Training), a member of the MDG (Mobile Diagnostic Group), a member of the Professional Tool and Equipment advisory board for Pten magazine, a committee member of Nastaf, and is a beta tester for multiple tool makers.
