Car batteries and things you’ll find useful to know


The battery is an essential part of your car. It needs to provide enough power to turn the engine over when it’s cold and the oil is thick, and supplement the vehicle’s alternator when the electrical load is high, when using lights and wipers in traffic, for example.

We take our battery for granted until the time when you turn the key and find that it’s flat. Battery issues are one of the top causes of breakdowns according to the AA – So how can you look after your battery and ensure you don’t get caught out?


How it works

Car batteries use a lead/acid technology that’s been around for many years. It has lasted so long because it’s relatively cheap and is able to function in harsh environments with temperature changes, vibration and dirt.  It is also because we have companies like MOT Gloucester who can be found at sites like who look after our cars and give them a full check every year.  This is not only for legal purposes for also for a good sell on rate when you decide to part with the car.

The battery stores energy and releases it in a chemical reaction when needed. It’s charged up by the alternator when the engine is running. The battery isn’t just used for starting, however, it stabilises the voltage while the engine is running, ensuring that everything operates smoothly. It’s also used to power accessories when the engine is off and ensures that there’s power available for the central locking and alarm.

Batteries work harder in vehicles that are subject to lots of stops and starts – something that’s more common, thanks to modern energy saving technology that turns the engine off when stationary – and in those subject to regular high speed running.


It’s free and could stop all kinds of small problems before they become large ones. Inspect your car every now and then to make sure that everything is OK. Buy your own tyre pressure gauge and check the air in your tyres. From reading the manual you will know what pressure they should be, and the optimal pressure can save you money by helping the car to use less fuel. Check the tread on the tyres too, and replace them when it gets below the recommended level.

Battery life

Car batteries can last for three years or more, but when they get to that sort of age they should be inspected annually to ensure they’re in good condition. You can easily check the fluid level – many modern batteries have a see-through casing to allow you to do this. Check also for leaking that may cause corrosion around the terminals on the support tray.

Signs that your battery may be reaching the end of its life are that the engine turns over more slowly when you start it – this is more pronounced in cold weather. You may also find that the charge light stays on when the engine is running.