Inner workings of a lead acid battery

ALTHOUGH A MYSTERY TO MANY, LEAD ACID BATTERIES ARE NOT AS COMPLICATED AS OFTEN THOUGHT. WE DELVE INTO HOW THIS WELL-ESTABLISHED TECHNOLOGY WORKS AND WHY IT HAS SURVIVED THE TEST OF TIME

The lead acid battery is the oldest form of rechargeable battery technology. They are used for a wide range of applications including cars, scooters, golf carts, UPS (Uninterruptible Power Supply), medical equipment, telecommunications, and even large grid-scale power systems. The inner workings of a lead acid battery are a mystery to many but here is a quick rundown by the battery experts at R&J Batteries.

The lead acid battery was invented in 1859 and despite being in use for over 160 years, the basic principles on which a lead acid battery works have not changed much. A lead acid battery consists of three major components — a positive plate (cathode) made of lead dioxide, a negative plate (anode) made of sponge lead, and an electrolyte solution of water and sulphuric acid. The positive and negative plates are submerged in an electrolyte solution to facilitate a controlled chemical reaction which allows the battery to store and supply electricity.

During charging, electrons are loaded onto the negative plates. As the quantity of electrons increases, the state of charge (SoC) and voltage of the battery increases. When the negative plates cannot hold any more electrons, the battery is considered to be fully charged. At 100 per cent SoC, the electrolyte in the battery contains approximately 30 per cent sulphuric acid and 70 per cent water.

When a battery is connected to an electrical device, the electrons begin to flow through the device and do their work (i.e, producing light or motion).

As the battery discharges, electrons flow onto the positive plates and the resulting chemical reaction reduces the amount of sulphuric acid in the electrolyte, replacing it with water.

When a lead acid battery is being charged it will generate some bubbles, however if a battery is charged too aggressively, it will begin to gas excessively as the plates are unable to convert the energy fast enough.

Aggressive charging will also generate heat which will damage the plates by causing them to shed some of the active material, reducing the battery’s capacity. The plates can also warp or distort which can increase the chance of an internal short circuit.

There are a number of different types of lead acid batteries in the market. Calcium and EFB (Enhanced Flooded Battery) are called flooded batteries because the plates are submerged in the electrolyte. AGM (Absorbent Glass Mat) batteries use the glass mats to separate the plates and also hold the electrolyte in suspension which makes the AGM battery non-spillable.

For those who prioritise quality and performance above all else, ACDelco batteries are an excellent choice. The global leader’s product portfolio consists of automotive, commercial, deep cycle, marine, and lawn mower batteries covering a wide range of applications.

ACDelco batteries are exclusively distributed by R&J Batteries in New Zealand through its branches in Wiri, Christchurch, Hamilton, Albany, Nelson, and an extensive network of stockists.

To learn more about ACDelco batteries, please call 0800 546 000, or visit rjbatt.co.nz.