The modern car battery is frequently what’s known as ‘maintenance free’. That means there’s very little you can do to ensure it’s in tip top shape, other than keep it charged. But how do you know what kind of battery you have?
What are the different types of battery?
Broadly speaking there are two types of battery: standard flooded lead acid batteries and Absorbent Glass Mat (AGM) which provide the extra power that cars fitted with stop-start need. But there are also maintenance free and non-maintenance free car batteries. The majority of modern cars are fitted with maintenance free batteries. This means they need little upkeep.
How do you look after a car battery?
The most important car battery maintenance you can do is to keep it charged. If you drive a car regularly, this should happen naturally: the car’s alternator will charge the battery.
If you’re planning on leaving your car and not really driving it for long periods of time, you should start it up and run the engine for around 20 minutes about once every two weeks. This should ensure the battery gets a decent charge.
If you have a garage or a private and secure parking space, you could charge the battery. You don’t have to remove the battery from the car in order to do this with modern ‘smart’ chargers. It’s important to follow any instructions over how the battery should be charged. In particular, connecting and disconnecting the charger’s clamps in the right order.
If you are charging a battery in an enclosed space, you must ensure good ventilation. This is because charging batteries can release large quantities of hydrogen which can be explosive.
The best battery chargers
The best way to keep a battery in good shape is to use a smart charger. The more intelligent ones slow charging down as the state of charge increases. They will also condition the battery and maintain them in a high state of charge ready for when you want to use the car again.
The best chargers can even help to repair damaged cells by doing what’s known as desulphation. This is when the sulphur that’s built up on the battery’s internal plates is dissolved back into the electrolyte, returning the battery to peak efficiency.
Buy a battery tester
As we’ve said before, these are very cheap and help give you an idea of how long your battery is going to last. You can buy them online with prices starting at about £10.
What about non-maintenance free batteries?
Non-maintenance free batteries need to be topped up with distilled water periodically. With summer heat and the need for the alternator to charge the battery frequently in cold weather, the fluid in the cells can evaporate.
If you are topping up the water in your battery, take extreme care and wear protective eye equipment. If you’re unsure what you’re doing, take your car to a professional.