How to jump start a car
Unless you know what you're doing, delving under the bonnet to check for or correct faults can be dangerous. We generally recommend that you seek professional assistance.
Check the vehicle handbook before using jump leads. All include general advice on jump-starting but some include model specific procedures. If this is the case you must follow the manufacturer's procedure rather than the steps described below.
Jump starting a vehicle can be a safe procedure however and damage can be avoided if a few simple rules are followed:
Keep metal objects out of the way rings, watch straps, hand tools, clips or stray wires just brushing a battery post can cause a spark, possibly exploding the battery and releasing the acid.
Don't attempt to jump-start a battery that is leaking or looks damaged it could explode.
Avoid smoking or naked flames batteries give off flammable gases so an explosion could result.
Keep hands well away and avoid loose fitting clothing, particularly scarves or neckties with the engine running it's easy to get caught-up and seriously injured on moving parts like pulleys or belts.
Don't use jump leads if they're damaged broken conductors or damaged clamps can overheat and may catch fire.
Step by Step
Park the two cars close enough so that the jump lead can reach both batteries, but make sure the cars don't touch. Ensure both ignitions are off and the cars are in neutral, and. raise the bonnets
Carefully connect the RED positive (+) cable to the positive (+) terminal on the flat battery. Then connect the other end of the red cable to the positive terminal on the working battery.
Connect the BLACK negative (-) cable to the negative (-) terminal on the working battery. On your car, attach the other end of the black cable to a metal point (such as a bolt or bracket) that is away from the dead battery. This will act as an earthing point
Check that the leads are well away from any moving engine parts such as drivebelts or the cooling fan. Start the engine of the working car. You can rev it a little if you wish (as long as it's in neutral and the handbrake is on!).
After about a minute, try starting the car with the dead battery. If it doesn't start, leave it a little longer and try again, however if the jump leads get hot, you must switch off the engine to prevent them overheating and causing a fire.
Once you have your car running, leave the engine on for a few minutes to help charge the battery a little more.
Remove the jump leads in the reverse order to the way you connected them, taking care not to touch them together or against any metal surfaces. If your car won't start after attempting a jump start, you may have a more serious problem with the battery, alternator or ignition system and should call your mechanic or breakdown service.