“Why did my battery fail? I never even used it?”

This is a common question from people who wonder why their batteries fail after being left on the shelf, or in a car that is not running, for an extended period of time. The problem is sulphation.

The chemistry in the battery requires reversible reactions that maintain a state of equilibrium as the current flows, meaning that the lead sulphate salts that form can be broken down and this state of equilibria maintains the life of the battery. However, if a battery stays on the shelf for a long time or stays in an unused car, lead sulphate forms without being broken down.

Because of this, a white salt layer forms inside the battery and settles around the battery’s active material, blocking the pores of the separators. This restricts the flow of electrons, and in the worst case scenario, cuts the circuit off completely as the current cannot flow. As more and more reaction surface becomes sulphated, there would be increased resistance in the battery, resulting in overheating.

 A sulphation problem can be identified by noticing whiteness in the eye of the battery, which should be green for a healthy battery fitted with a magic eye.

This issue can easily be overcome. Ensure that if when you are not using the car for a long period, you start the car engine frequently and let the engine run for a few minutes to allow any sulphate salts being formed to be broken down. You can do this once a week, running the engine for a minimum of 15 minutes. It’s useful to also take a short drive, which helps keep everything in good working order.

For retailers, the best option is to have chargers on site and to charge the batteries at least once every month, maximum two months, to ensure that you maintain the integrity of the battery. For those retailers with no chargers, a rotation agreement can be arranged with Probe, so that your stock can be charged and returned in good condition.

The problem of sulphation is most common in lead acid batteries, so if you purchase this type of battery be sure that it hasn’t been on the shelf without being charged for too long, and don’t leave it inactive at home. There is no reason to invest in good batteries, only for them to lose value and and exceed the warranty replacement time period without being used.