How to jump start a car

Finding you’ve left your car lights on and drained the battery is a bit of a downer. While these days most cars are smart enough to turn their headlights off for you, that doesn’t mean you can’t flatten your battery.

Something as simple as leaving the interior light or running the stereo while you wash the car can be all it takes to discharge the battery. It mightn’t be completely flat, mind you. But it mightn’t have sufficient charge to crank-over the engine – which is where jump starting comes in.

Step-by-step guide to jump start a car:

Simply, jump starting is supplementing the remaining charge in your battery with the charge from another vehicle or power source. Typically the car with the flat battery is temporarily connected to a car with a fully charged battery via jumper cables – also known as jumper leads.

The alternative to using another car is connecting to a stored-power device or ‘jump starter pack’. These are available from auto accessory stores from around $70. A quality set of jumper cables meanwhile can be purchase for as little as $30. Cheap insurance, indeed.

Before you attempt jump starting the car, it’s important to determine that your battery is indeed flat. The most obvious way to do this is to turn the ignition to start and listen for the usual cranking sound from your car’s starter motor.

If it sounds like it’s struggling to turn the engine, or does absolutely nothing at all (perhaps making a clicking noise), there’s a fair chance you’ve got a flat battery.

We need to emphasise at this point that although most cars can be started using the procedure detailed below, it’s imperative you consult your owner’s manual before attempting to jump start your car.

Some cars’ batteries are not under the bonnet… Some cars have dedicated remote jump starting terminals… Some car-makers warn against any form of jump starting… And some vehicle’s engine control unit (or ‘engine computer’) may be damaged by a sudden surge of electricity, requiring in expensive repairs. SO ALWAYS CHECK YOUR OWNER’S MANUAL FIRST.

Step One:
Before you even think about opening the bonnet or battery compartment, make sure your car’s transmission is set to Park (or Neutral if it’s a manual) and the park brake is firmly set. Turn the ignition off, open the bonnet and locate your battery.

So you don’t damage your car (or worse still yourself), it’s important to make sure you jump start your car correctly. Electrocution is a very real risk of an incorrect jump start procedure, but can be easily avoided by recognising the positive from the negative terminal of your car’s battery.

The positive terminal is marked with a plus symbol (+) and/or red-coloured marking, where the negative terminal is identified by a minus symbol (-) and/or black-coloured marking. You’ll find the same markings and colourings are applied to the jumper cables – just so you can’t get it wrong.

Step Two:
Once you’ve determined which terminal is which, it’s time to enlist the help of passer-by. Make sure they’ve followed the steps above before you make any connection with the jumper cables, but importantly, that they leave their car running. The reason we do this is so that the added strain for starting your car doesn’t leave your good Samaritan friend with an equally flat battery.

Now, with the two cars parked closely enough for the jumper cable to reach, it’s time to make the first connection.

Making sure the jumper cables aren’t tangled up, clamp the positive (red) jumper cable to the positive terminal of the flat battery, and then to the positive terminal of the running car. Then follow the same procedure with the negative (black) cable.

Some vehicles may specify that the negative cable is connected to the engine block or another earthing point of the disabled car – and not the battery. Always check your owner’s manual to ensure that’s not the case.

Step Three:
With the connection made, it’s best to wait a minute or two to ensure the flat battery has enough charge to start the car. After a short time, start the car as you usually would and disconnect the jumper cables in the reverse order to that listed above.

It’s important that once your car is running that you don’t switch it off for at least 30 minutes. The flat battery will take time to recharge. The best way to achieve a full charge is to go for a drive as higher engine speeds will charge the battery more quickly that it would sitting at idle.

That’s it!
It really isn’t rocket science. Now that you know how to jump start your car you can give yourself a high five. Best yet, you’ll be able to get yourself or somebody else out of trouble – and know that you’ve done it safely.