Car batteries, questions and problems: Car battery advice

Car battery problems are the cause of many thousands of roadside rescue calls every winter – and whilst most motorists are aware that cold temperatures can play havoc with a car battery, few realise hot sunny days can be even worse!

Extremely hot weather and overcharging are the two main reasons for shortened battery life – your battery contains liquid and heat causes it to evaporate. Low fluid levels will damage the internal structure of the battery.

Generally speaking, we motorists are often more aware of the importance of water, oil, clutch, break fluid levels, and tyre pressures, than issues with the battery. When it comes to the bit of kit that fires the engine into life and gets us going, keeps us warm, drives the windscreen wipers, powers the navigational system and dash cam, and lights the road up at night, we’re often a little in the dark.

In this short article we’ll look at just a few of the questions we’re asked about car batteries – most often at the roadside when attending a call-out for a battery related problem.

If your car  engine won’t start, it is often because the battery is dead. If this is the case, you may need to charge the battery, or for an immediate quick fix, a boost from a pair of jump leads.

However, if your vehicle has a charging fault, it may still not start, even after a jump or lengthy period of recharging. Or, it may start after a boost, only to run flat again after a few short miles.

To help pin point the cause of your flat battery there are a few simple checks you can carry out, such as:

Identify its level of charge by turning on the headlights. If their brightness is normal, the battery is not at fault. Whereas, if the lights are dim, but brighten when the accelerator is pressed, or they don’t come on at all, it is more than likely a battery fault.

Check the voltage using a voltmeter. If the battery is fully charged it should be around 12.6 volts with no load. If the reading is below 12.45 volts, its a sign that your battery needs to be recharged, or replaced.

Check whether the battery is holding charging using a hand held electronic battery tester

Often, the cause of your car battery not working will be obvious, such as accidentally leaving your lights or radio on. In this case, you will simply need to jump start it.

Once you have jump started your vehicle into life, you will need a journey of approximately thirty minutes or so to allow time for the battery to recharge itself.

If your vehicle fails to start and you hear a clicking sound rather than the reassuring sound of the engine, or there is complete silence when you turn the key, then a dead battery is likely to be the issue. If it starts then dies this is also a sign of a dead battery.

Often, it is on-board electrical equipment that drains the battery – it may seem obvious but it’s important to switch off the lights and radio etc. when you leave your car overnight and for long periods.

Cold weather is a major cause for batteries losing their charge, so minimising the use of non essential electrical equipment during these times is always a good idea. For more information on battery cold winter care please see our article Car batteries, Cold Weather and Winter Tips and Advice

Car batteries charge themselves whilst the vehicle is being driven, but it won’t fully charge itself during short journeys. The cars alternator plays a big part in helping the battery to charge itself – but if it becomes corroded, or has a loose connection it cannot function correctly, and the battery will run flat.

If you suspect there is an issue with the alternator or starter motor, you will need to consult a professional.

Under normal conditions and with the proper care, the life expectancy of a car battery should be between three and five years

When you need a new battery, simply visit the RAC Shop; enter your vehicles registration, make and model – choose the right battery, and decide if you want to fit it yourself, or leave the job up to a professional by contacting us here at the RAC shop.

Whichever battery you have, make sure you use the right charger. Choose the correct charger for your battery by clicking on the link, or if you would prefer to speak with one of our advisors regarding the appropriate battery or charger for your vehicle, then give us a call on 0800 8620676. We are here to help.

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