How to Jump a Car

By laura.cox

Posted in: 

September 27, 2022

3 Simple Ways to Jump Start a Car 

There’s never a convenient time to turn the key in the ignition of your car and hear that dreaded clicking sound. When your car will not start and the engine sounds more tired than you feel before the coffee you were just about to drive for, you know you have a dead battery. The causes of a dead car battery can vary, and it can be a sign of other growing problems. But for now - when you just need to get going - a jump start is the answer. 

If you drive a car, sooner or later you will encounter this problem. As a result, jumping a car is a skill every driver should have at the ready, like changing a tire or checking the oil. There are a few different ways to jump a car, from using a battery jump charger to car jumper cables to bump starting a manual transmission car. Jumping a car should not take you more than 20 to 40 minutes, depending upon how much of a recharge your car battery needs. 

Jump Starting Safety 

Before you start working on a car battery, safety should be your first concern. Although jumpstarting a dead battery is a reasonably safe procedure, it does involve transferring an electrical charge and as a result, some risk exists. Any time you are working with your car battery, keep the following mind: 

  1. Check your vehicle user manuals, as cars have specific instructions to follow before jump starting. Some cars have separate connection points meant to be used instead of the battery terminals, while others may not even allow jumping at all. 

  1. Wear protective gear such as rubber gloves and safety goggles. Remove any loose metal jewelry. 

  1. Avoid the risk of arcing by keeping your car batteries (or battery and jump starter) as far apart as the cables will allow. Make sure the cars aren’t touching, because if they do there is a risk of a small explosion. Also, don’t touch any of the metal connections directly yourself. 

  1. Make sure both cars (or car and jump starter) are off and that keys are out of the ignition before attaching or adjusting the connecting cables. 

  1. Attaching the cables is the most dangerous part of this process. The order in which you connect the cables to the battery terminals matters, so be cautious. 

  1. The most important thing to remember, though, is not to allow the positive and negative clamps to touch once you start connecting them to the batteries. 

If you pay attention to these precautions, you shouldn’t have any problems while jumping your car. 

Troubleshooting a Low Car Battery 

There are many reasons why your car won’t start, so before you jump a car, you should make sure your car battery needs a jump start in the first place. A jump will only help if the battery needs to be charged. 

To make sure you don’t have another issue: 

  1. Check the Headlights: If these are dim, it is a good sign that the battery in your car needs a jump start. If they are still bright and the car won’t start, your battery isn’t the problem. 

  1. Test the Car Electronics: Radio, internal lights, automatic windows, and other car electronics will get weaker or won’t work if your car battery is low on charge. If these are still working normally, it could be a starter problem and not a car battery problem. 

  1. Watch the Dashboard Displays: The dashboard should light up when you turn the key in the ignition, even if the battery is dead. If it doesn’t, the ignition switch may be the culprit.  

  1. Try Starting the Car: If the engine turns weakly or only makes a ticking sound, the battery charge is low, and you probably need a jump start. If the engine is turning over strong but not starting, the battery isn’t the problem. 

Once you eliminate these other possibilities and determine that a jump start is your answer, try any of these ways to jump-start a car. 

Using a Battery Jump Starter 

Try jumping a car using a car battery starter. This method is easy and comes highly recommended. A car battery starter is a small power bank or battery pack that fits easily in your vehicle and comes in handy in such emergencies. Unlike a car battery charger, which needs to be plugged in and slowly refills the battery, a battery jump starter stores and delivers enough charge to start your car directly. They can store their charge for several weeks or months, depending upon quality. 

To use a car battery starter, follow these steps: 

Preparation 

  1. Make sure the car is off and the keys are out of the ignition. 

  1. Locate the positive and negative terminals on your car battery. The positive terminal will be marked with ‘P’, ‘POS’, or a ‘+’ symbol and have red wires, and the negative terminal will be marked with ‘N’, ‘NEG’, or ‘-’ and have black wires. 

  1. If the terminals have dirt or corrosion on them, clean them off with a rag before jump starting. 

  1. Find the positive (red) and the negative (black) charging cables on the jump starter. 

  1. Be sure that the battery jump starter is off, and make sure not to touch the positive and negative clamps together. 

Connection 

  1. Attach the positive (red) clamp to the positive terminal on your car battery, checking that the connection is secure and won’t shake loose. 

  1. Attach the negative (black) clamp securely to a metal section of the car’s frame, rather than the negative terminal of the car battery. Make sure the connection point is clean and unpainted and is a non-moving metal part of your car. It should be as far as possible from the battery, fuel lines, and carburetor, in case of a spark. 

  1. When the clamps are connected, turn the portable jump starter on. 

  1. Try to start the car, but don’t keep the key turned for more than a few seconds on any attempt. 

  1. If the car doesn’t start, wait a few minutes before trying again. 

Disconnection 

  1. When the car starts, turn off the jump starter. 

  1. Disconnect the negative (black) clamp first, then the positive (red) clamp. 

  1. Let your car idle for a few minutes before driving, then drive for at least half an hour to allow the alternator to recharge the battery. 

While these general instructions work for most car battery jump starters, refer to the owner’s manual for your specific device. They can have different specifications, voltages, limitations, and restrictions. If you follow the above process, jumpstarting a dead battery is nothing to worry about. 

connecting-jumper-cables

Steps to Jump a Car with Jumper Cables 

But what if you don’t have a jump starter? The next method of jumping a car involves getting by with a little help from your friends.  

This involves connecting your car jumper cables to a car with a functioning battery and is the most familiar way of jump starting. Here the cables are used to connect both batteries in parallel and bypass the dead battery to start the other car. 

Before you try to jump start your car, make sure the other car battery is the same voltage. Most vehicles use a standard 12-volt battery, but some commercial or industrial vehicles use higher voltage batteries that can overload your car electronics. 

Hooking up jumper cables is easy if you follow these steps: 

Preparation 

  1. Park the car with the charged battery roughly three feet (nearly a meter) from your car, with the batteries lined up. Ideally, you want the cables to just reach both batteries comfortably without much slack between. Not all car batteries are in the front of the vehicle, so make sure you know where it is before lining up the cars. 

  1. Make sure both cars are off, and the keys are out of the ignitions. 

  1. Open the hoods and find the positive and negative terminals on both car batteries. The positive terminals will be marked with ‘P’, ‘POS’, or ‘+’ symbols and have red wires, and the negative terminals will be marked with ‘N’, ‘NEG’, or ‘- ‘and have black wires. Identify the positive (red) and the negative (black) charging cables on the jump starter. 

  1. Check battery terminals for corrosion or dirt and clean them off with a rag before jump starting. 

Connection 

  1. First attach one of the positive (red) clamps of the jumper cables to the positive terminal on the dead battery, checking that the connection is secure and won’t shake loose. 

  1. Next attach the other positive (red) clamp to the positive terminal on the live battery, again checking for a secure connection. 

  1. Then attach the negative (black) clamp to the negative terminal on the live battery 

  1. Attach the other negative (black) clamp securely to a metal section of the dead car’s frame, rather than the other negative terminal. Make sure the connection point is clean and unpainted and is a non-moving metal part of your car. It should be as far as possible from the battery, fuel lines, and carburetor, in case of a spark. 

  1. When all the clamps are securely connected, turn on the car with the working battery, and allow it to idle for about 5 minutes to transfer charge into the dead battery. 

  1. When the batteries have had time to transfer enough charge, try to start the dead car. If it does not start, try to connect the car jumper cables again. Turn off both cars and remove keys from their ignitions before adjusting the clamps. 

Disconnection 

  1. When both cars are running it is safe to disconnect the jumper cables in reverse of the order they were attached, beginning with the negative (black) cable attached to the car frame. 

  1. Next disconnect the negative (black) clamp from the negative terminal on the live battery. 

  1. Then remove the positive (red) clamp from the positive terminal of the live battery. 

  1. Finally disconnect the positive (red) clamp from the positive terminal of the dead battery. 

  1. Don’t turn the car with the dead battery off until you have driven it for about half an hour, to allow the alternator to recharge the battery enough to start again. If you turn it off too soon, you may need to jump start your car again. 

  1. Remember to do something nice for the friend who came to your rescue! 

This process may look intimidating, but it’s quite simple once you get started – and before you know it, you’ll be back on the road. 

How to Bump Start a Car 

The final way to jump a car doesn’t require any kind or cables or battery connections – but it is only available to cars with a manual transmission. Instead of using another stored charge for a battery jump, you can use momentum and clutch to bump start cars. All you’ll need is a slight incline to roll down or some volunteers with strong backs. 

Preparation 

  1. Move the car to a position with open space ahead to roll. 

  1. Press the brake and the clutch pedal. 

  1. Shift the car into second gear. 

  1. Turn the key in the ignition to the first position - turning on the car, but not far enough to start the engine. 

Starting 

  1. With the clutch still held in, release the brake. If you are on a hill, the car should begin to roll, otherwise, it’s time for your mighty volunteers to push for all they are worth! 

  1. When the car reaches five miles per hour (8 kilometers an hour), release the clutch and the engine should start. You may need to engage and release the clutch again if it doesn’t start. 

  1. Drive your car for at least half an hour to let the battery recharge, or you could have trouble starting it again. 

  1. Thank your volunteers for their assistance! 

With these three methods of jump-starting a car available to you, there’s no reason to panic over a dead car battery. 

Troubleshooting Other Car Starting Problems 

While jumpstarting a dead battery is a quick and effective way to get your car going at the time, battery problems can be a sign of other problems with your car. A few warning signs to pay attention to are: 

  • Failed jump starting attempts: If your car is not jump starting, even after repeated attempts, then your battery isn’t just drained of charge: it will need to be replaced. Car batteries are affordable and easily replaceable. 

  • Frequently drained battery: A dead battery can be caused by something as minor as leaving the lights on overnight. But if your battery shows up drained repeatedly, it means that the car engine isn’t recharging the battery like it is supposed to. This is often an indicator of a problem with the vehicle’s alternator. 

  • Dead car with a full battery: When your car won’t start but the car electronics are working normally, the problem is with the starter, or – if the dashboard doesn’t light up – with the ignition system. 

If you encounter any of these problems when you jump a car, taking your car to a mechanic for a diagnosis could identify and resolve a bigger issue. 

Ask an Online Mechanic 

No matter how easy it is to jump start a car, when your vehicle won’t start you have a problem – and often you’ll have to figure it out on your own. If you find that you need jump-start help, the voice of experience looking over your shoulder can make all the difference. 

Start an online chat with a professional mechanic on JustAnswer, and you have access to that experience in minutes, from anywhere you have internet access, at any time. Discuss the specific details of your car, share photos of your cable connections before you begin the jump start, and troubleshoot in real-time if something isn’t working right. You don’t ever have to face an automotive problem alone again!