How to Jump Start a Car
As anyone that’s ever accidently left their radio, lights or in-car phone charger switched on overnight will tell you, there’s nothing worse than putting your key in the ignition and discovering that your battery has run flat. This can lead to missed appointments, late arrivals, and in some cases, serious inconvenience. The good news is that jump starting a car is easy and safe to do. Below you’ll find a detailed runthrough of everything you’ll need and what to do, so you can get your car up and running again. Pick up the required tools from our jump leads and battery booster packs ranges. What You’ll Need To Jump Start A Car Here are the tools you’ll need to jump start your vehicle: Jump leads or a charged battery booster pack Rubber gloves The vehicle with the dead battery Another vehicle with a fully-charged battery The first thing you’ll need in order to jump start your motor is a reliable set of jump leads. These will normally consist of two clamps placed at both ends of a protected length of cable - one will be red, the other black. If you’re using a booster pack, this also has the same red and black leads and clamps that connect directly to the power pack. If you notice any of the leads are a little worn or that the metal cable has frayed through the protective rubber coating, you’ll need to replace them immediately. Remember, these cables are going to be used to transport a significant number of volts from one battery to another, and if any areas are exposed, you run a real risk of electrocution. While you may be tempted to buy the cheapest set available, we’d recommend spending a little more and getting a set of jump leads with a length of no less than 3m - this should be more than enough to get you out of even the tightest of spots. Lastly, if using jump leads, you’ll also need a second vehicle with a battery. Ideally, this vehicle will be of a similar size to the one you’re looking to jump start, although it is possible for tiny engines to jump start larger ones, provided you allow a little more time to let it to charge. If you don’t own another vehicle you may want to consider asking a nearby motorist or neighbour to see if they’ll help you out. Before You Jump Start Like with any car maintenance, safety is absolutely essential. Make sure you’re aware of the following before initiating a jump start. The Battery Don’t attempt a jump start if the battery is leaking or has visible damage. Replace it if this is the case Avoid using jump leads with any faults or damage to them If the leads become hot, stop using them immediately The Jump Leads or Power Pack Don’t disconnect the leads while the engine is running, as this can damage electronics in the vehicle The Environment Make sure there are no naked flames or sources of smoke nearby Avoid working with any metal objects that could cause a spark (rings, necklaces etc.) Don’t wear any dangling pieces of clothing, like a scarf, which can get caught in the engine Jump Starting A Car With A Battery Booster Pack Provided you have a charged-up power pack, the process to jump start your car is relatively straightforward Place the pack somewhere close to the battery, on a stable and flat surface. Connect the red positive (‘+’) lead from the battery pack to the positive (‘+’) terminal of the car battery. Then connect the black negative (-) jump lead to an earthing point on your car such as unpainted metal on the chassis. Once that’s done, switch the battery pack on, turn on the engine and leave it running for around 5 minutes. After 5 minutes, switch off the pack and keep the engine running for a further 5 minutes. Disconnect the leads in the reverse order; negative (black ‘-’) terminal first, then the positive (red ‘+’) terminal. Put the battery pack on charge once done for when you need it next time. Jump Starting A Car With Jump Leads Step-By-Step Now that you’ve managed to acquire some jump leads and a pair of rubber safety gloves, you can use your jump leads to start your engine using the steps listed below: Start by getting the driver of the second vehicle to park their car close to yours, ensuring they park bonnet-to-bonnet without touching. Also make sure the handbrake is on and ignition is off. To see whether they’ve parked close enough, grab the jump leads and gauge whether or not they’ll reach from your car’s battery to that of the second vehicle Ensuring the second vehicle’s engine is switched off, attach one end of the red lead to the positive (marked with a +) terminal on your car’s battery. Just be careful here – make sure that the other end of the red jump lead is away from any metal parts within the engine bay, or the second vehicle. The red and black ends of the jump lead should also never touch, as this can cause a spark Next, attach the other end of the red jump lead to the positive terminal on the second vehicle. If you’re struggling to locate the positive terminal on either motor, it will be the larger of the two and in most cases, will be marked with a ‘+’ sign Repeat the steps above with the black jump lead, ensuring that one end of the black lead is connected to an earthing point such as unpainted metal on the chassis Next, leave both engines off for 3 minutes and then start up the second vehicle and allow it to tick over for 1 minute After this time has passed, engage the engine in the vehicle with the flat battery and leave both cars for 10 minutes Once done, you should disconnect the jump leads in reverse order of how you connected them - again making sure they don’t come into contact with any metal surfaces - before closing your bonnet. As a reminder when disconnecting the jump leads, switch off both engines and remove the black (negative) lead first, followed by the red (positive) jump lead Get into the car with the dead battery and check if it starts up. If your car still doesn’t start, there might be a deeper issue which requires an engineer. What To Do After A Jump Start After a successful jump start, we recommend going for a 30-minute drive to help the battery build up a normal charge. Avoid stop-start traffic if possible so the charge is consistent. Conclusion After following all of these steps, your jump start should be successful and the car ready to drive. If you’ve noticed that your battery keeps running flat overnight, even with all your vehicle's electronics switched off, it’s likely you need a new battery. Luckily, finding a battery to suit your vehicle couldn’t be easier - simply enter your registration on this page and we’ll do all the legwork for you. You can also brush up on your car battery knowledge with our expert guide. Jump Start FAQs What Are Jump Leads? Jump leads should be part of any driver’s checklist. They’re comprised of 4 alligator clips that connect to the positive and negative terminals of a battery; the red ends connect to the positive terminal, the black ends connect to the negative terminal. How Do Jump Leads Work? Jump leads are designed to create an electrical connection between a dead battery and a working one. Electricity is transferred between them, granting essential power to the flat battery. What Is A Battery Booster Pack? A portable power source used to immediately start a vehicle with a dead battery via leads without needing another car. It is different to a car battery charger which charges the battery over a period of time. Does It Matter What Order You Put Jumper Cables On? Yes, it’s essential that your jump leads are connected in the correct order to avoid sparks and other damage. Remember: start with the red jump lead to the positive terminals, and then the black lead to the negative terminal/earthing point. Does Revving The Engine Help When Jumping A Car? Revving the engine is unlikely to help much when jump starting a car. The voltage that’s generated is minimal, so you’re best leaving the jump leads to do their job. Can You Jump Start A Car When It’s Raining? You can jump start a car in the rain, but it’s best to shield everything under the bonnet to avoid the risk of damage.Euro Car Parts29 October 2025