We were recently part of a media group that visited the Auto X battery factory in Port Elizabeth. AutoX manufacturers the two leading battery brands in South Africa, Willard and SABAT. AutoX also manufacturers the HiFase batteries aimed at export markets in Africa and Europe. And recently the company added the VARTA brand to its portfolio of battery products.
AutoX supplies a number of batteries to Original Equipment Manufacturers (OEMs), in other words , to manufacturers of brand new cars, as well as to the aftermarket for replacement batteries. The company has over 3 000 automotive retail clients across South Africa.
We saw how the batteries are made
During our visit we were able to see how the batteries were manufactured, including the injection-moulding processes for the plastic battery casings, and all the other lead-acid battery-assembly processes that result in the 12-volt batteries that provide the energy storage for motor vehicles.
At the end of our factory tour we asked Kelvin Naidoo, AutoX’s Manufacturing and Technical Director, to explain to us the basics of how a battery stores electrical energy.
The battery appears as a plastic box with two poles or terminals on the top
A car battery appears to you or I as a solid plastic casing with two metal poles emerging through the upper casing at either end. These poles, or terminals, are made of lead and are marked with a Positive and Negative sign. In most modern cars the positive pole is connected to the electrical systems that require energy, such as the starter motor, audio system and lighting system, while the negative pole is the “earth” pole, and this terminal is connected to a plane metal part of the car body via a stout cable and a bolt.
A look inside a modern lead-acid battery
If you were able to prise off the upper casing of the battery (don’t try this at home folks, battery fluid is dangerous! ) you would be able to see that the two poles are connected to a series of lead-oxide(positive) and lead (negative) plates arranged in sequence throughout the battery’s six cells, or compartments. Each of these cells provide two volts of energy, and as they are ultimately connected to each other, the total energy available is 12 volts.
The electrical charge is held, due to a reaction between the plates and the battery fluid
Before the battery leaves the production line, each of these six cells is filled with the fluid that facilitates and holds the electrical charge. This fluid is essentially a solution of sulphuric acid and distilled water. The series of positive and negative plates (made of lead alloys) remain immersed in the battery fluid throughout the battery’s life.
When an electric charge is applied to the battery via positive and negative terminals on top of the battery, this current is fed through to the series of plates. The positive plates in each of the cells are interconnected, as are the negative plates, by metal connectors that run along the top edges of the plates. The positive and negative plates, arranged in packs side by side, are, however, separated by insulators.
The electrical charge to these plates, which are in constant contact with the battery fluid, causes a chemical reaction to occur in the battery fluid, and this energy is thus retained to be utilised when you need to start the car, turn on the lights, or listen to music.
Charging and re-charging cycles
When you activate the starter button, the electrical energy in the battery supplies the power to turn the start motor. This drains a large amount of the stored energy out of the battery. However, a car is fitted with a device called an alternator which immediately begins re-charging the battery to the required level once the engine is running. A regulator prevents the battery from being overcharged.
If a car is left unattended for too long, the battery will discharge, as there is an on-going chemical process in play in the battery that causes reaction between the plates and the fluid. In this case the battery needs to be removed and recharged by a battery charger.
Kelvin Naidoo explained that the batteries made by AutoX carry a 25-month warranty. But typically a battery will last much longer, although modern demands on batteries in cars has increased in recent years.
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