A flat battery is one of the most common breakdown causes. While many motorists call their breakdown provider for help, it is possible to jump-start the car yourself. Read our step-by-step guide to learn how.

What you’ll need

• A set of working jump leads

• The vehicle with the flat battery, which needs to be in a position where jump leads can easily reach the battery

• Another vehicle with a fully-charged battery (it’s best to avoid a hybrid or electric car as this could cause damage)

• A pair of rubber work gloves (for safety)

Important safety note before you get started

As with all aspects of electricity, safety should be a priority:

• Connect the jump lead cable to the flat battery first. Allowing energy to flow into the cables before they are connected to the flat battery could present an electrocution hazard.

• Never try to jump-start a battery that appears to have been leaking, or that has sustained any damage.

• Do not use damaged jump leads.

• If you feel the jump leads are getting hot, stop using them.

• Ensure loose garments like scarves and jewellery are never near either car's moving parts.

• Ensure no metal objects (rings, watch straps, tools, etc.) touch either of the car batteries, since this could generate a spark that might potentially result in a battery explosion.

• Do not permit naked flames anywhere near the battery (including cigarettes and lighters).

• Never disconnect the cables while either of the engines is running. Doing so could result in serious damage to both vehicles' electronics.

If you're unsure about any aspect of this process, contact your breakdown provider, or someone who has the necessary experience to perform a jump start.

How to jump-start a flat car battery

To jump-start a flat car battery, you'll need access to another, fully operational car, and a set of jump cables. It's a good idea to store a set of jump cables in your vehicle, just in case; it could save you a lot of time and stress.

Ensure the batteries are near each other

Move the functional car close to the car with the flat battery. Parallel or nose-to-nose are both fine. Aim to have about two feet of distance between the two engines, or as close to this as possible. However, do not let the vehicles touch.

Turn off both cars fully

Wait for three minutes.

Connect positive to positive

Begin by connecting the red clamps (positive) of the cables to the positive terminals of the flat battery. These should be marked, but may be difficult to see if the battery is grimy. Ensure you have a firm connection to the right parts of the batteries.

Connect negative to negative

Next, attach the black (negative) cable clamps to the negative terminal of the working battery, then connect the negative terminal to a metal part of your car that is unpainted (e.g. engine block or chassis).

Start the engines

Turn the ignition of the working car (in neutral and with the handbrake on), pump the accelerator a little and let the engine run idle for one minute. The flat battery will begin to charge.

Start the car with the flat battery

With the cables still connected, try starting the car with the flat battery. If it doesn't start, let it charge for another minute.

Remove the cables

Once you have enough charge to start the engine, it's time to remove the cables.

Ensure both engines are off.

Disconnection should be done in reverse order to the way they were connected. Detach the negative cable from the car that had the flat battery, followed by the negative cable on the other vehicle. Then disconnect the positive cable from the car that had the flat battery, and last of all, the positive cable from the other car.

Take your car for a drive

Give your battery some additional charge by taking your car on a longish drive. But do note that, given the fact it has run flat, it may need to be replaced. Visit your local garage to see if you need a new battery.

More jump-starting options

If the jump cable method didn't work for you, here are two other approaches you can try:

Battery pack jump

Instead of using the battery of another car, you can jump-start a vehicle with a portable battery pack. This method works in a very similar way to the traditional jump start. Be sure to follow the instructions, especially in relation to the order of connection.

Call your breakdown provider

If you do not have access to another live battery, or the experience needed to jump-start a vehicle, you should call your breakdown service provider. If you are not a member of a breakdown service, you can call one out and join at the same time, or contact a local garage.

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