Which batteries have the best warranties?

By Stuart Johnston

Car batteries generally have a two-year warranty in the South African market, but you can expect them to last much longer!

Up until a few years ago, car batteries sold in South Africa generally came with a 12-month warranty.

However, a few years ago, most battery manufacturers in our market moved to a two-year (24-month) warranty.  Currently (excuse the pun), SABAT and Willard batteries come with a 25-month warranty, which gives them a slight edge over their main competitors.

How long do batteries last?

The answer to this one  depends on how they are cared for, and how the car is used. And these two factors are interlinked.

If a car is driven only occasionally, or on short trips only.

If a car is driven only occasionally, and on short trips, the chances are that the battery will be operating below par. The reason for this is that when a car stands, the battery is slowly drained of its charge. This occurs even if there are no immobilisers with tiny winking lights slowly draining the battery. If there are immobilisers at play on your car, the drain on the battery will be more severe over a period of days or weeks when it stands idle.

Does driving the car recharge the battery?

Driving the car regularly recharges the battery. The car has a device known as an alternator – that’s the piece of equipment  driven by the fan (or ancillary) belt with wires protruding from it – that is designed to recharge the battery as you drive it.

But the recharge rate on an alternator is slow

Most alternators are designed to slowly recharge the battery, replacing the energy you drained form the battery after cranking the engine to start it. If you only do very short trips – say to the shops (or the office) and back – the drain on the battery from two successive start-ups may not be fully replenished by the alternator if the distance to the shops (or workplace) – is a short one.

So what can I do to make sure the battery is kept charged?

The easy solution to keep the battery recharged is to ensure that one or two of your trips during the week involves driving the car for at least 15 to 20 minutes, and preferably even further. This will ensure that enough charging takes place to replenish the battery’s power to its required level.

What else can I do?

If the car stands idle for long periods, it is firstly a good idea to disconnect the earth cable on the battery – this is the one with the terminal marked with a minus (-) sign. This wire is an earth wire and is always connected to a bolt on the bodywork, or in rare cases,  an engine bolt. Disconnect this wire at the battery only,  and place it alongside the battery, in the engine compartment. It is a two-minute job to reconnect it with the correct spanner (typically a 10 mm or 13 mm spanner), before starting the car.

What about battery chargers?

It is a good idea to recharge your car’s battery with an inexpensive trickle battery charger if the car is required to stand idle for long periods. Buy a battery charger that automatically prevents the battery from being overcharged. If a car battery is left to run completely flat over a long period, the plates inside the battery will suffer from sulfation, which is the build-up of lead-sulfate crystals that form on the battery plates. A short-term build-up of these crystals can be reversed by charging, but if they are allowed to build up over a long period, they will render the battery useless.

How  long can a well-cared for battery last?

A well-cared for battery can last from between four to eight years. Even more. The writer’s battery in an old Mercedes-Benz W123 has been in place for nine years without any problems!