Left feeling flat? How to jump start your car

There are few worse feelings than returning to your car, turning the key to start the engine and hearing nothing. You might need a jump start – here’s how to do it.

That deafening silence just when you’re expecting to hear your motor roar into life. A tell-tale ‘click’ perhaps, in place of the sound of the engine starting. Maybe a darkened instrument panel with no lights illuminated where you would normally expect to see them blazing away.

These all point towards a flat battery and, therefore, a car that just won’t go. It’s a sinking feeling, but one that doesn’t need to last long – if you know what you’re doing. Anyone can learn how to jump start a car with a flat battery using jump leads, which take power from a good vehicle (or other source) and use it to fire some life into your stranded motor.

Starting a car with jump leads

To jump start your car using jump leads you are going to need another vehicle, so assuming you can call a friend, family member, or enlist the help of a fellow motorist, get them to pull up alongside your car, and open both bonnets.

Take your jump leads (you do carry some in your car’s boot, right?) and untangle and sort them so they are separate, a red lead and a black lead. They have a large spring-loaded clip at each end called a crocodile clip which attaches to the battery terminals of your dead car and to the helpful good car. It’s important that these are connected in a certain way to avoid damaging either car or giving yourself a nasty shock.

Find out where both cars’ batteries are and make sure the cables are going to reach them. That might involve moving the running car until it is positioned so that both batteries are close together. Remove any covers on the terminals but don’t disconnect any other wiring. Check your jump leads are in good order without exposed cables and make sure both batteries are not damaged or leaking.

Check your surroundings to ensure that where you’re working is safe and remove any loose clothing that could become entangled in either working engine. If you have long hair, tie it back.

With both cars switched off, attach one clip from the red lead to the positive terminal on the flat battery. It should be coloured red or have a plus (+) symbol on or near it. Then take the other end and attach it to the positive terminal of the good battery.

Next attach one end of the black jump lead to the negative terminal (-) of the good battery and attach the other black lead’s clip to an earthing point such as bodywork or a metal part of the stranded car’s engine.

Now start the good car’s engine and let it settle to an idle. When you’re happy it’s ticking over nicely, try to start the dead engine. It should burst into life but if it doesn’t, don’t panic. Let everything stay running for five minutes and try again. It should now start. If it still doesn’t fire up you might have a bigger problem than a flat battery.

But let’s assume it has started, so remove the leads in the reverse order that put them on: negative from the metal surface, negative from the good car, positive from the previously stranded car, positive from the good car. That's it, you've just learned how to jump start a car!

Power pack

You can buy power packs which are portable storage units that can be charged up at home and then kept for months holding their charge. They will have red and black leads and connecting them up is similar to using jump leads. Put the red (+) crocodile clip on the positive terminal of the flat battery and then the black (-) clip on the negative terminal. That should provide the spark you need to get the car going.

Remember that in all cases, everything should be done carefully and methodically and with the recognition that you will shortly have two running engines in front of you which must be treated with respect.

Do all of that carefully, and you should be up and running again in no time.