How to jump start a car in nine steps (with video)

Learning how to jump start a car is such an invaluable piece of knowledge it should almost be part of the national curriculum.

It’s a horrible feeling - jump in the car on a winter’s morning, turn the key, and the starter motor clicks but fails to trigger the engine into life. 

This may mean a dead battery but, if you battery is merely flat and needs a bit of a jolt back to life there are different ways of jump starting a car.

Below we outline the different techniques use our quick links to find the right section for you:

- How to jump start a car

- How to bump start a car

- How to jump start with a booster pack


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How to jump start a car with jump leads

The most common and effective means of getting your car going with a flat battery is by using jump leads.

Using jump leads

What do I need?

Safety precautions before starting

A lot of electricity runs through jump leads when jump starting a car, so it’s important not to take risks. If you’re not confident that you know what you’re doing, give the RAC a call and we’ll be happy to help.

  • Check for damage - if there’s any obvious damage to either of the batteries, or the jump leads, don’t risk attempting a jump start
  • Remove any rings or metal jewellery you’re wearing, and make sure nothing metal touches the terminals on the car’s battery
  • If the jump leads start to get hot, disconnect them (but be VERY careful when doing so)

Nine steps to jump start a car

  1. Before starting, make sure any electrical systems or devices in the car with the dead battery are switched off (Lights, CD player, internal sat-nav etc).
  2. Park the running car with its ‘live’ battery (usually located under the bonnet next to the engine, but occasionally in the boot) as close to the ‘flat’ battery in your car as possible, without the vehicles touching.
  3. Turn both vehicles off, remove the ignition keys and open their bonnets (or boot if the battery’s located there). 
  4. Attach one end of the red jump lead to the positive terminal on the flat battery. The ‘terminals’ are located on the top of a battery, the positive terminal will have a plus (+) symbol on it. 
  5. Then attach the other end of the red jump lead to the positive terminal of the live battery.
  6. Attach one end of the black jump lead to the negative terminal of the live battery. This can be identified as the terminal with the minus (–) symbol.
  7. Then attach the other end of the black jump lead to unpainted metal somewhere on the car with the flat battery (but away from the battery). This acts as an earth.
  8. Start the engine of the working car and leave it to run for a few minutes.
  9. Now attempt to start your car. If it doesn’t start after a few attempts, it might be more serious than a flat battery and you’ll need to seek professional help. If it does, leave both cars running for five minutes before disconnecting the leads.

How to remove the jump leads

If you have got the car successfully working again you will have to remove the cables in reverse order, without turning off their engines.

  1. Disconnect the end of the black jump lead that is connected to the unpainted surface.
  2. Then disconnect the end of the black jump lead that is connected to the negative terminal of the live battery.
  3. Disconnect the end of the red jump lead that is connected to the positive terminal of the previously live battery.
  4. Disconnect the end of the red jump lead that is connected to the positive terminal of the previously flat battery.

After the leads have been removed

Once you’ve got your car running, your battery will need a while to charge so don’t turn the engine off as you might be left stranded.

A 20-minute drive should charge the battery.

MORE ADVICE: 10 checks to prevent a breakdown this winter

How to bump start a car

If you haven’t got a second car you can use to jump start a vehicle, or a portable battery pack, it might be possible to bump start a car.

This only works with cars with manual gearboxes and usually requires at least two people - although you might manage on your own if you’re parked on a hill with plenty of room.

Three-step guide

  1. Turn on the ignition and place the car in second gear, with the clutch down. Release the handbrake and get someone to give the car a push to build momentum (or allow the car to roll downhill).
  2. When you’re rolling at around 10mph, lift up the clutch. Hopefully, the car will start with a jolt. If it does, let it run for at least 20 minutes to charge up the battery.
  3. The car might need a couple attempts to get it going. If you still can’t bump start it, attempt a jump start or seek professional advice.

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How to jump start a car with a battery booster pack

How to jump start your car

If you're worried about getting stranded with a flat battery when you are unable to call for help or seek assistance from someone, then you can buy a portable battery pack as a precaution, to keep you mobile if your battery run out of charge.

These can be purchased from as little as £30 and are able to jump start a car without the use of another vehicle.

Before you start

Before you start, it’s important to consider the safety aspects of jump starting a car.

Remove any loose clothing or jewellery – you don’t want a metal object to create a spark when attaching the leads to the battery’s terminal.

If the battery looks damaged in any way, avoid jump starting it and seek professional advice.

The battery pack itself needs to be charged before it can be used to jump start a car.

Most chargers need an overnight charge to ensure they have enough power to start a car.

Jump starting with a portable battery pack

The first step of jump starting a car is finding the battery. This is usually situated in the engine bay under the bonnet, but in some cars, it is located in the boot. It’ll probably be hidden under a plastic cover – unclip this and you should see a large battery with two terminals.

Connect the positive (red) lead from the battery pack to the positive (+) terminal of the battery. Connect the negative (black) lead to the negative (–) terminal. Although many battery packs now have built-in protection should you connect the leads the wrong way round, it’s better to do it correctly in the first place.

Be careful where you position the battery pack while you’re using it. If it’s placed on the engine it might fall off when the vehicle starts.

Once the battery pack is connected, attempt to start the car as you normally would. It might hesitate at first, but don’t keep trying if it doesn’t start within about 10 seconds.

In this event, seek professional help by calling the RAC or consider replacing your battery. They can be bought in the RAC Shop from around £60 and can be delivered the next day, or fitted the same day by one of our patrols.

If the car does start, keep the engine running to charge up the battery. Consider taking it for a drive for 20 minutes or so to avoid the car failing to start next time you need it.

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