A flat battery may not be the only reason for your car being unable to start. However, if you turn the key and nothing happens, your engine struggles to crank or you hear clicking from the starter motor solenoid, it’s most likely that you just have a flat battery.
If you have a pair of jumper leads handy and access to another car, you should be able to get yourself back on the road in no time.
What will I need?
You will need two jumper leads. One has red clips on each end for positive and the other has black clips on each end for negative. The battery terminals of each battery will also be marked with a + for positive and – for negative.
It is recommended to only use jumper leads with built-in surge protection. These are designed to protect the delicate electronic systems of today's cars from damaging power spikes.
Please also note that the donor car must have a fully charged battery with the same voltage as yours, usually 12V. Jumper leads can cause damage to both cars and people if they’re not used properly so it’s important to follow these steps correctly.
Locate and check each battery
The first step is to locate the battery in each car. They're usually found under the bonnet but some cars have their battery located in the boot.
Check each battery for damage. If you see any damage, corrosion or fluid leaking, you're safer calling in roadside assistance.
Position each car correctly
Park both cars close to each other so that the jumper leads can reach both batteries. Place each car in park or neutral if the car is a manual, apply the handbrakes and turn them off.
Attaching the jumper leads
Pick up the red jumper lead and clamp one end to the positive terminal of the dead battery.Then clamp the other end of the red jumper lead to the + positive terminal of the donor battery.
Pick up the black jumper lead and clamp one end of the lead to the negative terminal of the donor battery.
Clamp the other end to some clean unpainted metal on the dead car's engine block (like a bolt or bracket) that is away from the battery. This connection acts as an earthing point. DO NOT attach it to the negative terminal of the dead battery.
Start the engine
Start the engine of the donor car first and let it run 1-2 minutes to charge up the dead battery
Start the car with the dead battery. If your problem was a flat battery, it should start straight away. Let both cars run together for a couple of minutes.
Remove the jumper leads
Remove the jumper leads in reverse order. So first remove the end of the black negative jumper lead attached to the dead cars engine block, then the other end of same lead to the good battery's negative terminal.
Next, the red positive lead from the positive terminal of the good battery, then the other end of that lead from the positive terminal of the previously dead battery.
Drive your car
You should be good to go. However your flat battery will need more time to recharge so drive around for a good 20 to 30 minutes before turning off your engine.
Don’t have any jumper leads with you?
If you drive a manual vehicle and have some friends to help push your car, or you are parked on a hill, it's possible to bump start your car.Simply turn your ignition on and press down on the clutch. Then put your car into first gear and release the handbrake to get the car moving.
Once you are travelling about 5-10mph, quickly take your foot off the clutch and the engine should start.
Your flat battery will need time to recharge so drive around for a good 20 to 30 minutes before turning off your engine.
