Find someone with a car who’s happy to help. Their car must have a fully charged battery with the same voltage as yours (usually 12 volts).
1. Line up both cars
Park both cars so their batteries are within easy reach of one another (without the cars actually touching).
Keep the handbrakes on and the ignitions off.
2. Connect the red jump lead
Use the red jump lead to connect the working battery’s positive (+) terminal to the flat battery’s positive (+) terminal.
3. Connect the black jump lead
Take the black jump lead and attach it to the negative (-) terminal on the working battery.
Then attach the other end to an earthing point (unpainted metal on the engine block or chassis) well away from the flat battery and fuel system.
4. Start the other car
Keep both engines off and wait for 3 minutes, then start the working car’s engine and let it run for 1 minute.
5. Start your car
Turn on the engine in the car with a flat battery.
6. Let both cars run
Leave both cars to idle, at a fast pace, for around 10 minutes.
7. Turn off and disconnect
Turn off both cars’ engines and carefully disconnect the leads in the reverse order to the way they were connected (remove the black lead from your car first and finish with the red lead from the other car).
Make sure the leads don’t touch one another, or either car, as you remove them.
8. Restart your car
Try turning the keys in the ignition to see if your car will start up.
9. Call for help
If your car won’t start there’s probably a more serious problem requiring professional help.
If you’re still stuck, you can call us on 0800 88 77 66 or by using the AA app.
On average, batteries last between 5 and 7 years but you should only consider changing a car battery when it's showing signs of deterioration.
If the battery's more than 5 years old and seems like it's struggling to start the car, get it checked out. It's better to be safe than sorry - it'll be worse if it's a roadside emergency or on a cold morning when you're already late for work.
If you have breakdown cover with us, we'll come out to test your battery to see if it needs a charge or if you need a new one. You can find out more about breakdown cover with our guide.