Here’s how to save a lead-acid battery

Peter Palm of CAR Magazine shares tips on how motorists can extend the life of their vehicle’s battery.

Lead-acid batteries will be with us for a while longer till the much improved Li-ion variety finally take complete control.

The lesson

I learnt a hard lesson during the many months of lockdown. Cars were left idle and batteries went flat. To be prepared I had a car away from home permanently connected to a battery charger. It didn’t work and the battery was unable to start the car. I removed the battery, took it home and proceeded to investigate.

The lie

We have all read the advertising on top of a battery. Maintenance-free, it says, or something similar. This is not true. It may be so for the first two to three years but then the level will inevitably drop until the lead plates are no longer submerged in acid. This is when the battery begins to descend into scrap value, or junk-status like some economies. It was too late for this one, but there were others and I immediately examined those.


Battery types

The variations of lead/acid include flooded, gel and AGM. Most remain flooded, meaning plates covered by sulphuric acid. Gel uses a silica to thicken the electrolyte and AGM means absorbent glass mat, all to prevent spillage and reduce evaporation. But not permanently.

The solution

Like so many problems, the solution is quite simple. Start by removing the plastic advertising on the battery. Next, find the plastic cover plate that takes the place of the older individual screw-in caps. Price it off with a screwdriver and hey presto. You look down into the individual six cells making up a 12V battery.

Top up

I bought a five-litre jug of distilled water from a spares shop. It was just as well I didn’t buy just one bottle as the amount I needed was substantial. One battery needed a full two litres of water while a second required 1.5-litres. These lead acid batteries were around three years old. Now, two years later, they are still all working fine.


It is easy to forget the passing years, especially as one gets older. Ideally, one should check the levels once a year. I believe these batteries can still last up to eight years or more with regular checks. Oh, and if at all possible, never let a battery run completely flat. They can only handle a few flat episodes before giving up and dying. For motorcycle batteries, a smaller charger may be needed. The one illustrated can handle 6V batteries too. Handy for those load-shedding portable LED lamps.

Read the original story on CAR Mag.

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