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How to start a car with a flat battery

A dead car battery can quickly turn your morning from good to bad. You may be in a rush to get somewhere and jumpstarting a car can take time and effort, however it can be done in around 30 minutes.

Your vehicle’s battery charges as you drive and, when purchased from new, should last around five years without running out of power. However, if you don’t drive your car very often or only take short journeys, you may find that the battery becomes flat. If you don’t drive your car very regularly, it could help to run the car’s engine for around 15 minutes once a week to ensure the battery stays charged.

If the battery is flat and the engine won’t turn on, there are a few ways you can jumpstart your car’s battery.

How to Jump Start a Car with Jump Leaves

The most common and easiest way to jumpstart a car is with jump leads and another vehicle that has a charged battery. Before you do anything, perform a quick check to ensure that the battery isn’t damaged or leaking any liquid and that the key is out of the ignition of both cars.

Step 1: Position both cars relatively close together so they’re facing bonnet to bonnet but not touching. Leave enough space so you can comfortably fit between the cars. The jump leads should be able to reach both batteries easily without too much tension. If the leads are too taut, move one car slightly closer. Step 2: Double check that both cars are in neutral with the handbrakes on. Step 3: You should have two jump leads - one black and one red. First attach the red lead to the positive terminal of the flat battery. Then attach the other end to the positive terminal of the car with a charged battery. Be careful not to touch any metal in the engine bay while doing this. Step 4: Connect one end of the black lead to the fully charged battery and NOT the flat one. This is important. The other end of the black lead should be clipped onto a metal bracket or bolt in the car with no charge away from the battery. Do not attach it to the negative terminal of the dead battery or on any moving parts. Step 5: Double check that all your leads are plugged in where they should be and wait for around three to five minutes before you attempt to turn the engine on. Doing this allows the voltage to equalise between the two batteries. Step 6: Start the engine of the vehicle with the charged battery and let it run for around a minute. Once this time has passed, try to turn on the engine of the vehicle with a dead battery. If it doesn’t turn over straight away, wait a couple more minutes and try again. Step 7: Once both engines are on and running, leave them for around 10 minutes. You should stay with them during this time. Step 8: Now that your battery has been recharged, it’s time to remove the jump leads. Leave the engine on while you do this and make sure that the clamps on either end of the leads don’t touch any part of the car. Remove the leads in the following order:

1. Black lead on the car with the flat battery

2. Black lead on the other car

3. Red lead on both cars (it doesn’t matter which order) Step 9: Leave your car running for another 20 minutes before taking it on a relatively long drive (30 minutes or longer). It’s important to get the engine’s revs above 1,000 rpm as this will charge the battery faster.

If you find that your car’s battery is regularly without charge, it may be that you need a replacement. You can either take your car for a free battery check or purchase a new battery.

Can you jump start a diesel?

A car that runs on diesel fuel instead of petrol can be jump started in a similar way to the method above. The only difference is that you may need to source some jump leads that are a little more heavy duty than standard ones. This is because diesel cars often have larger engines.

A diesel car can be jump started with another diesel car or a petrol one - it doesn’t matter.

Can I Jumpstart a Motorcycle with a Car Battery?

It isn’t recommended that you try to restart a motorcycle battery using a car. Car batteries tend to be more powerful and you could risk damaging the motorbike’s electric system. Instead, you should use another motorcycle or a battery pack.

How to Jump Start a Car Without Another Car

Jumpstarting a car with another vehicle is a relatively straightforward process, however, you might not have a second vehicle available to do this. So what are your other options? You can try jumpstarting your car with a battery pack. As previously mentioned, you should make sure that the battery isn’t damaged beforehand. It might also be a good idea to remove any metal jewellery and ensure that items of clothing that could get in the way, such as scarves and ties, are removed.

The battery pack can be treated in the same way as the second vehicle in the steps we’ve listed above. As before, the red lead should go from the battery pack to the positive terminal on the car’s dead battery. The black lead should be clipped to a non-moving part in the engine away from the battery terminal. Once all the leads are attached, you can turn on the battery pack.

Leave the pack for a few minutes before turning the engine on. When you’ve managed to start the car, keep the engine running for at least 10 minutes, switching off the boost pack after this time has elapsed. Then, keep the car on for around 20 minutes.

Your vehicle’s battery should now be fully charged. You should disconnect the leads, doing the black lead first and then the red one. Ideally, you should drive the car for around 30 minutes to ensure the battery won’t go flat again any time soon.

If your car wont start or you need any further assistance, don't hesitate to contact us and we will be happy to help.

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