If you're readingthis, then the chances are that your car has a flat battery.In this car maintenance guide, we show you how to jump start a car in two different ways, firstly, using jump leads and secondly a booster pack, with simple steps and a video too.
Please note, jump starting a car can cause damage to the vehicle and the battery if not performed correctly - so contact a professional mechanicor get in touch with the RAC if you are unsure or have any questions about the process.
If you're not sure that the issue isdefinitely being caused by the battery, find out how to tell if you have a flat battery here.
The most common and effective means of getting your car going with a flat battery is by using jump leads.
What do I need to jump start a car with jump leads?
Typical car battery
- A second vehicle with a fully charged battery. Avoid using a hybrid or electric car as this could cause damage.
- A pair of quality jump leads. You can buy a set of jump leads from the RAC shop.
Safety precautions before jump starting a car with jump leads
When jump starting a vehicle, it’s important not to take risks.
Consult the owner's manual first and if you’re not confident that you know what you’re doing, contactRAC Breakdown and we’ll be happy to help.
- Check for damage - if there’s any obvious damage to either of the batteries, or the jump leads, don’t risk attempting a jump start
- Remove any rings or metal jewellery you’re wearing and make sure nothing metal touches the terminals on the battery.
- Before starting, make sure any electrical systems or devices in the vehicle with the dead battery are switched off (Lights, radio/CD, sat-nav etc) and if possible, lower the drivers window.
- Park the second vehicle as close to the casualty vehicle as possible, without the vehicles touching, ensuring the jump leads will comfortably reach from one battery to the other.
- Ensure both vehicles engines are switched off, remove the ignition keys and open their bonnets (or boot if the battery’s located there).
- Attach one end of the red jump lead to the positive terminal on the flat battery. The positive terminal will usually have a red plastic cover with a plus (+) symbol on it. Pull the cover back to access the terminal.
- Then attach the other end of the red jump lead to the positive terminal of the good battery on the second vehicle.
- Attach one end of the black jump lead to the negative terminal of the good battery.
- Then attach the other end of the black jump lead to a good earth point on the casualty vehicle – a solid metal part of the engine is usually best.
- Now attempt to start the casualty vehicle. If it doesn’t start after a few attempts, it might be more serious than a flat battery. In this event, seek professional help by contacting the RAC.
- If it does start, leave it running for about five minutes.
- Switch off the casualty vehicle, disconnect the negative jump lead then check the engine starts again okay. Disconnect the remaining jump leads.
Attach the other end of the black jump lead to a good earth point on the casualty vehicle – a solid metal part of the engine is usually best
How to safely remove the jump leads
- Switch off the engines on both vehicles
- Disconnect the black jump lead that is connected to the casualty vehicle
- Disconnect the other end of the black jump lead from the second vehicle
- Disconnect the red jump lead that is connected to the second vehicle
- Disconnect the other end of the red jump lead from the battery on the casualty vehicle
After the leads have been removed
Restart the engine on the casualty vehicle.
The battery will need to recharge fully for it to be fully serviceable, which is best achieved using a quality battery charger for several hours.
In the meantime, if possible, drive the vehicle normally (not in heavy traffic) for around 30 mins to try to put some charge back into the battery.
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The RAC do not recommend bump startingvehicles.
Please follow the advice in theHow to jump start a car with jump leads orHow to jump start a car with a portable battery pack sections.
If you're worried about getting stranded with a flat battery when you are unable to call for help or seek assistance from someone, then you can buy a portable battery pack as a precaution, to keep you mobile if your battery goes flat.
These can be purchased from the RAC shop and are able to jump start a car without the use of another vehicle.
- 10 checks to prevent a winterbreakdown
- What to do if you have a flat battery
- Car battery conditioners and trickle chargers – everything you need to know
Before you start
When jump starting a vehicle, it’s important not to take risks. Consult your owners manual first and If you’re not confident that you know what you’re doing, contactthe RACand we’ll be happy to help.
- Check for damage - if there’s any obvious damage to either of the batteries, or the jump leads, don’t risk attempting a jump start
- Remove any rings or metal jewellery you’re wearing and make sure nothing metal touches the terminals on the battery.
Jump starting with a portable battery pack
First check that the battery pack is fully charged.
Locate the vehicle battery - usually situated in the engine bay under the bonnet, but in some vehicles, it is located in the boot. It’ll probably be hidden under a plastic cover – unclip this and you should see the battery with its two terminals.
Connect the positive (red) lead from the battery pack to the positive (+) terminal of the battery. Connect the negative (black) lead to a good earth point on the casualty vehicle – a solid metal part of the engine is usually best.
Stand the battery pack on the ground next to the vehicle, the leads are usually long enough to reach the battery. Avoid placing it on the engine as it might fall off when the engine starts.
Once the battery pack is connected, switch on the pack and attempt to start the vehicle as you normally would. If it doesn’t start after a few attempts, it might be more serious than a flat battery. In this event, seek professional help by contactingthe RAC. If you need a repair, you can contact an RAC Approved Garage or RAC Mobile Mechanic.
If the vehicle does start, keep the engine running for about 5 minutes. Switch off the engine, then switch off the battery pack and remove the leads from the battery pack. Now restart the engine again.
The vehicles’ battery will need to recharge fully for it to be fully serviceable, which is best achieved using a quality battery charger for several hours. In the meantime, if possible, drive the vehicle normally (not heavy traffic) for around 30 mins to try to put some charge back into the battery.
If your MOT is due or if you would like to book your vehicle in for a full car service, you can book online with a RAC Mobile Mechanic or your local RAC Approved Garage today.
Hopefully you won't need this information anytime soon, but make sure you havebreakdown cover,van breakdown coverorbusiness breakdown coversorted just in case!
