How to jump start a car

By , 5 October 2023

8 mins read

There’s nothing worse than getting in your car and finding out the engine just won't turn over. In situations like this, you may need to jump start the vehicle to give it a boost.

If you’ve never needed to know how to jump start a car before then it can feel like an intimidating process.

However, the good news is that by following the steps below, you’ll be equipped with the knowledge to get your motor up and running again.

What are the signs that your car needs a jump start?

You need to jump start a car if the battery voltage has dropped below what is needed to turn the start motor or keep the car running if it is using electronic systems to run the pump(s), injectors and so on. But what can cause this to happen?

What can cause car battery issues?

It’s likely you will recognise one of the issues below when you’re thinking about why your battery is having problems – whether you’ve got an old car, you’ve been letting the battery rattle around for a while or you suspect a parasitic drain...

Before you dive in and dig out the jump leads, you’ll need to reduce your risk of damaging the vehicle – and yourself...

Safety first!

Should you jump start a hire car?

It’s all well and good if you are jumping your own car so you can get to work on time or leave a car park, but if you’re encountering this issue with a hire car then you should proceed with caution. Consider the information below before you try to fix the issue yourself.

If you find yourself in a situation where your hire car battery is dead, it's generally advisable to follow these steps:

What you’ll need

If you have decided to jump start your car, here’s what you will need for the job:

Ensure that the jumper cables you use are in good condition, with no exposed wires or damage to the insulation.

It's also crucial to choose the appropriate gauge of jumper cables for your vehicle. Thicker gauge cables can carry more current and are suitable for larger vehicles with larger batteries.

How to jump start a car with jump leads

Now it’s time to jump your car. Follow the steps below to get the job done:

Open the bonnets.

Open the bonnets of both vehicles.

Identify the batteries.

Locate the batteries in each vehicle. They are typically rectangular or square boxes with two terminals: one positive (+) and one negative (-).

Identify the jumper cables.

Jumper cables come in pairs. One cable is colour coded red, and the other is colour coded black. Red is for positive (+) and black is for negative (-).

Each cable has two clamps (four in total), so you have two red clamps and two black clamps.

Connect the jumper cables.

Follow this sequence carefully:

Now wait for five minutes.

Start the working vehicle.

Start the engine of the working vehicle and let it run for a few minutes to charge the dead battery.

Attempt to start the dead car.

Try starting the dead car. If it starts, let both vehicles run for a few minutes to allow the dead battery to charge.

Remove the jumper cables.

In the reverse order of connection:

Drive the previously dead car.

Let the previously dead car run for a while to ensure the battery is fully charged. Then, drive it around for at least 15-20 minutes to charge the battery further.


Don’t forget that jump-starting is a temporary solution. Consider getting your car looked at by a professional, and bear in mind that you may need to replace the battery.

If you have jump started a hire car, it’s recommended to tell the car hire company so they can get the battery looked at.

About the author

Dom has loved cars since he was five years old. He has worked as a mechanic for years, relishing the opportunity to be around vehicles and keep them in top shape.

Dom trained as a driving instructor once his daughter got her first car so he could help people to stay safe on the roads.

Now he takes every chance he can to share his knowledge of cars with the general public, focusing on vehicle maintenance and safety.