No luck? Leave it for a few minutes and try again.The sick car should now start when you turn the key.Build its engine revs to 2500rpm to produce a strong current.Start the healthy car's battery and let it run for a minute.Connect the lead to the positive terminal of the healthy car.Connect the 'live' lead to the positive terminal (marked +) to the car with the flat battery.Connect the same lead to the negative terminal of the other car.
Connect the negative lead (black) to the negative terminal marked –.First off, ensure both cars are off and attach the jump leads to the flat battery.'How to jump-start a car with leads?' can be explained in ten easy steps: Jump packs used to be relatively unwieldy devices, but lithium-ion technology means they are now highly portable.
JUMP STARTERS FOR CARS PORTABLE
Jump packs are portable batteries that you can charge at home and then hook up to your car battery to get its engine spinning. Your second option is to use the car salesperson's friend – the jump pack. The downside of this system is you need another healthy car and someone with the time and will to help you out – not things you can always guarantee to find. Once the engine's sparked – and assuming there's nothing else wrong (like a faulty alternator) – from there the car can charge its own battery.
Essentially, you're sending the power from a healthy car with a charged battery to the other car with a flat battery – the slug of electricity is enough to crank the sick car's engine and, with a few turns, it spins into life. Thirty years ago it was common to see two cars with their bonnets open, with a pair of cables connecting their batteries – this was jump-starting.