Could Sulphation Damage Your Car's Battery?

Posted on: 30 September 2022

Many vehicle owners understand that a car battery has a finite life and will eventually need to be replaced. Yet they may not realise that certain steps can be taken to extend the life of a battery and especially if the vehicle to which it is attached is largely dormant. For example, why is it a good idea to disconnect the battery if you intend to leave your vehicle unused for an extended period? What can happen if you do not do this?

Understanding Battery Drain

The main purpose of a car battery is to provide the necessary boost of power to kickstart the engine when needed. Once the engine starts, the alternator takes over to generate power for operation, but the battery is still required to feed small amounts of power to ancillaries when the engine is off. This means that there is a permanent drain on the battery, which is relatively small but can nevertheless build up over time. A dashboard clock, alarm system and other products require a certain amount of energy which is provided by the battery when the engine is not running. Some other aftermarket devices can also put a drain on the battery even when not supposed to, which is often known as a "parasitic" drain.

Therefore, if the vehicle is left for some time with the battery still connected, it will slowly discharge. If it is allowed to remain in this condition, a chemical reaction might occur known as "sulphation."

Avoiding Long-Term Damage

Sulphation can cause significant and potentially permanent damage to the battery. It creates an off-white coating on the battery's positive plate, and eventually, sulphate deposits inside the separators. It's a chemical reaction that cannot easily be reversed and is sure to affect the potency of the battery. In fact, it may not be possible to recharge the battery due to those sulphate deposits, and the unit may have to be replaced instead.

What to Do Next

So, if you intend to leave your vehicle unattended due to a long overseas holiday or for some other reason, consider disconnecting the battery. You can always take the vehicle to a mechanic for a service when you return, and they will check the battery's efficiency. This will help ensure it is in good enough condition to start the car as and when needed. However, if sulphation has occurred, you may have to replace the battery.

For more information, contact a car battery provider near you.