If you get in the car, turn the key, and nothing happens, there’s a chance you’re dealing with a flat battery. A jump start– also known as a boost – will recharge the battery and get the car running again.

Jump starting or boosting the battery works by taking power from another source and transferring it to the flat battery using special cables called jump leads.

Is it safe to jump start a car yourself?

It is safe to do it yourself as long as you know how to jump start a car properly. If you don’t feel confident jump starting a car yourself, feel free to give the team at Mt Roskill Collision Centre a call and we can help out.

There are a few different ways to jump start a car.

How to start a car with jump leads

Jump leads are the cables you use to restart a flat battery. They are the leads that transfer power from one source to another.

Use the steps below to start a car with jump leads by using another vehicle:

  1. Get prepared:
  • Check whether either vehicle is an electric vehicle – if the flat battery belongs to an EV, this isn’t the way to recharge the battery; if the helper vehicle is an EV, don’t use it and instead look for one to assist that isn’t an EV.
  • Have a look at the flat battery and check for signs of corrosion or leaking (if you notice either, don’t try to jump start the battery yourself).
  • Get out the jump leads (if you don’t have a set in your car, you’ll need to find a helpful driver who has a set and who is happy to assist).
  • Remove any dangling clothing (scarf or tie) that may get caught in the moving engine parts.
  • Remove any jewellery or metal accessories (rings, watches, necklaces) that may cause a spark.
  • Put out any cigarettes, and remove any e-cigarettes or vapes.
  1. Line up the vehicles:
  • Park the two vehicles so they face each other and are close enough for the jump leads to reach both batteries, but don’t let the cars touch each other.
  • Put both cars in ‘park’ with the handbrakes/parking brakes on and the ignitions turned off.
  1. Connect the leads:
  • Connect the red jump lead to the flat battery’s positive (+) terminal.
  • Connect the other red jump lead to the working battery’s positive (+) terminal.
  • Connect the black jump lead to the working battery’s negative (-) terminal.
  • Connect the other black jump lead to an earthing point; this is an unpainted metal surface that is away from the flat battery and fuel system, such as the metal strut that keeps the bonnet open.
  • Start the ignition of the car with the working battery (the helper car) and let it run for a few minutes.
  • Try to start the ignition of the car with the flat battery.
  1. If your car doesn’t start:
  • Make sure the cables are correctly attached. If they are, turn off the working car for a couple of minutes, then try again. If the car with the flat battery still doesn’t start, you will need to call your mechanic to check whether the battery needs to be replaced.
  1. If your car starts:
  • Keep both cars running for 5 minutes.
  • After these 5 minutes, you can turn off the ignition of both cars and disconnect the cables in the reverse order that they were connected.
  • Remove the black lead from the earthing point.
  • Remove the black lead from the helper car.
  • Remove the red lead from the helper car.
  • Remove the red lead from your car (the car that was boosted).
  • Make sure the leads don’t touch each other or either car as you remove them.
  • Restart your car – the car that has been boosted – and keep it running. (If it doesn’t restart, it hasn’t kept its charge; you should contact your mechanic for further checks.)
  • Once you’ve restarted your car, you will need to keep your engine running for at least 15 minutes to fully recharge your battery.

How to jump start a car without another car

Another way to jump start a car is by using a battery booster pack.

If you’d rather not call another driver for help or rely on the help of strangers, you might like to keep a car battery booster pack in your car just in case you ever encounter a flat battery.

The steps are similar to those above:

  • Start by checking the battery for signs of corrosion or leaks.
  • Put the battery booster pack somewhere stable – not on the engine, as it might fall off when the engine starts.
  • Make sure the battery booster pack is turned off.
  • Connect the red (+) jump lead from the battery booster pack to the flat battery’s positive (+) terminal.
  • Connect the black (-) jump lead from the battery booster pack to an earthing point; an unpainted metal surface that is away from the flat battery and fuel system, such as the metal strut that keeps the bonnet open.
  • Switch on the battery booster pack.
  • Try to start your car.
  • If the car starts, keep the engine running for about 5 minutes.
  • After 5 minutes, switch off the battery booster pack and allow the car’s engine to run for a further 10 minutes.
  • After these 10 minutes, turn off the car’s engine and disconnect the leads in the reverse order to how you connected them (first disconnect the black lead, then the red lead).
  • Restart your car and keep it running. (If it doesn’t restart, it hasn’t kept its charge and you should contact your mechanic for further checks.)
  • Once you’ve restarted your car, you will need to keep your engine running for at least 15 minutes to fully recharge your battery.

How long should it take to jump start a car?

The whole process takes about 25 to 30 minutes.

  • 5 to 10 minutes to get set up – check the appearance of the battery, remove dangling clothing, line up the cars (if using another vehicle), connect the jump leads
  • 5 minutes to keep the car running while connected to the power source (another car or the battery booster pack)
  • 15 minutes to keep your engine running to fully recharge

Do not rush the process. It is extremely important that you check the battery before trying to recharge it, connect everything properly and then let the boosted car run long enough to fully recharge.

How to jump start a car without jump leads

If you don’t have jump leads (or another battery to get power from), it is possible to jump start a car using a method called a ‘push start’.

This requires two people as it involves one person in the car and one person outside pushing it. Start by pressing the clutch, putting the car in second gear, and turning on the ignition without starting the car. As you gently release the brakes, the car will start rolling. Once it does, slowly release the clutch and have the person outside continue pushing the car until it builds momentum. Continue driving in this way to charge the battery.

It’s not the easiest way to jump start a car, but it is possible.

Can you jump start a car in reverse?

This push start process above can be done if the car is in ‘reverse’ gear. It may be necessary based on how the car was positioned when the battery died (for example, if there is no room to push it forward).

Be warned, however, that this method of jump starting a car in reverse can cause damage to the transmission and clutch.

Can I jump start a motorcycle with a car?

Jump starting a motorcycle is best done using the push method (and it’s easier to push a motorcycle than a car).

You can jump start a motorcycle with a car battery, but you need to take some precautions as a car battery usually has a higher voltage than a motorcycle battery and may damage it if this type of jump start isn’t done correctly.

Check that both vehicles use a 12-volt negative-to-ground system. It’s also easier to do if you have motorcycle jump leads. These have smaller clamps that make it easier to reach the terminals of the motorcycle battery.

Connect the jump leads in the same order as you would when boosting a car battery (see above).

The important thing to note when jump starting a motorcycle with a car is that you do not turn on the engines. Connecting the two batteries is enough to charge the motorcycle’s battery.

After about a minute, turn the key to the motorcycle and check that everything illuminates. If so, then it’s time to start the engine. Turn the engine on for only a second or two. If the engine starts, turn it off, disconnect everything, and then run the bike for about 15 minutes.

If after the one-minute connection, the bike’s ignition doesn’t start, leave it for another minute or two and try again. If after this time the motorcycle still isn’t starting, you’ll need to have it checked out by your mechanic. Don’t try to boost it by turning on the engines while the motorcycle and car are connected. This will cause damage to the motorcycle battery. There is a risk that you might burn out the electronics of the motorcycle because the battery of a car is more powerful.

An important consideration to make is that some vehicles may not be able to be jump started, therefore its important to contact your vehicle dealership before attempting to jump start your car.

To minimise the chance of having to jump start your car, it’s a great idea to test your car battery from time to time. Here is a good article explaining how to test your car battery.

Get in touch with the experts at Mt Roskill Collision Centre to book a battery check or replacement.

Call us on 0800 227 762 or email [email protected] for professional and friendly car servicing advice.