How to Jump Start a Car: Helpful Tips
It’s a sinking feeling that many drivers have experienced at one time or another — turning the key in the ignition and the car won’t start. Whether you left the lights on or it’s simply that the battery is old, even the most reliable car won’t start if the battery has been drained. With a little planning, though, you can be prepared if you ever need to give your battery a charge.
From having jumper cables in your car to calling for assistance, follow these tips for jump starting a car.
Using Jumper Cables
Before you hit the road, make sure you have jumper cables in your emergency car kit. That way, you’ll have the cables on hand if you ever need them. Once someone has arrived with a working car that you can use to charge your dead battery, and you have the cables in-hand, Edmunds suggests the following steps:
- Park the two cars close together but make sure they don’t touch. Then, turn both cars off.
- Put on eye protection in case of sparks, says Meineke.
- Connect the positive jumper cable (usually red) to the positive terminal on the “dead” battery. (Typically, the positive battery terminal is marked with a plus sign, while the negative is marked with a minus.) Now that the cable is attached to the battery, Meineke states that you should not touch the metal clamps to any metal other than as described below. Doing so could cause an electric shock.
- Connect the other end of the positive cable to the positive battery terminal on the vehicle providing the jump.
- Connect the negative cable (usually black) to the negative terminal on the vehicle providing the jump.
- Connect the other end of the negative cable to an exposed metal part of the vehicle with the dead battery. (Unpainted components like brackets, bolts, etc., often provide the best grounding, which may help prevent sparking.)
- Check that the cables are not near any moving engine parts.
- Start the “booster” vehicle, and let the engine idle for a few minutes. If the battery is a few years old or has been dead for a few weeks, you may consider revving the engine slightly on the booster car to speed up the charging process, says Edmunds.
- Start the disabled vehicle.
- If the car with the dead battery starts, let it run for at least 20 minutes, Consumer Reports suggests. If it doesn’t start, you may need to check the cable connections, according to Consumer Reports. If that doesn’t work, you may need a mechanic’s help.
- Keeping the jumper cable away from any metal, begin removing them in reverse order (to help prevent sparking). First, remove the black (negative) cable from the ground on the previously disabled vehicle (keep the vehicle running).
- Remove the other end of the negative cable from the battery of the vehicle providing the jump.
- Remove the positive cable from the battery of the vehicle providing the jump.
- Remove the positive cable from the previously disabled vehicle.
If you are not comfortable performing any of these steps, call a professional for assistance.
Edmunds recommends driving the jump-started car for at least 20 minutes to allow enough time for the battery to charge. Keep in mind that if the battery or alternator are not in good shape, you may need another jump start. Be sure to stop the vehicle somewhere safe, where you have assistance nearby should the vehicle not start again.
Call Roadside Assistance
Many auto insurers now offer roadside assistance plans for their customers, which often provide help with common situations, such as breakdowns, flat tires and dead batteries. It can be a relief to know professional help is just a call away (or click, as some providers offer apps as well) if your car won’t start. If you don’t have this service, you may want to consider adding it to your auto insurance coverage or purchasing a roadside assistance service plan.
After your car is running again, remember that a jump is meant to restart the disabled vehicle, not to recharge the battery. It may be a good idea to put the jumped battery on a battery charger, which you can buy at an automotive store, as soon as possible to help ensure that it’s charged to full capacity. If you’re unsure about the long-term health of your battery, consult a mechanic or a professional at an automotive store for advice.
Originally published July 25, 2018.
Animation showing white clouds floating in blue sky.
Title appears: How to Jump Start a Car
White animated car drives across the bottom of the screen.
Scene changes to a parking lot, with grass and bushes in the background and a blue parking sign nearby. A man in a business suit gets into a blue, four-door car.
Scene changes to the interior of the car. The man tries to start the car a couple of times and it won’t start.
Voiceover: A dead car battery can ruin anyone’s day, but a jump start from another vehicle may help you get back on the road. Follow these tips to jump start your car safely.
We see the exterior again. A yellow car pulls up to the blue car, so their front bumpers are facing each other.
Text box appears: 1. Park a car with a working battery close to the one with the dead battery
Voiceover: Park a car with a working battery close to the one with the dead battery. Make sure that the cars are not touching and that you have enough space to walk between them. Then, shut off the ignition on both cars, as well as any of the cars’ accessories, such as headlights, and open the hoods.
Text box appears: Safety tip: Be sure the cars are parked in a safe area away from moving traffic.
A woman gets out of the yellow car, and the man gets out of the blue car. We see car engine as the hood opens on the blue car with a dead battery, and then the opened hood and engine is shown on the yellow car. The woman walks to her car’s trunk and takes out jumper cables. Closeup of the trunk and jumper cables is shown.
Voiceover: Next, get the jumper cables.
The woman walks from her trunk towards the blue car while holding the jumper cables.
Text box appears: 2. Connect the batteries.
Show the engine on the car, focusing primarily on the dead battery.
Text box appears: Safety tip: Wear eye protection and rubber work gloves when jumping a battery.
Voiceover: Connect the positive jumper cable, which is usually red, to the positive terminal on the dead battery. The positive battery terminal is typically marked with a plus sign. Make sure the metal clamps do not touch any metal except the appropriate battery terminal.
A gloved hand is shown connecting the jumper cable as described. Text box appears to point out the positive battery terminal.
Voiceover: Next, connect the other end of the positive jumper cable to the positive battery terminal on the working car’s battery.
A gloved hand is shown connecting the jumper cable as described.
A text box appears to highlight the negative terminal on the working battery.
Voiceover: Now you’ll connect the negative terminals. First, clamp the negative cable, which is usually black, to the negative terminal on the working battery. The negative terminal is typically marked with a minus sign.
A gloved hand is shown connecting the jumper cable to the negative terminal as described.
Scene cuts back to the engine on the blue car with the dead battery.
Voiceover: To help reduce the risk of sparking, connect the other end of the negative cable to an exposed metal part of the vehicle with the dead battery. Unpainted components, like a bracket or a bolt, are typically a good option.
A gloved hand is shown clamping the jumper cable to an unpainted bolt, as described.
Text box appears: 3. Start the booster vehicle.
Voiceover: With the jumper cables connected, you can now start the car with the working battery. Let it idle for a few minutes. If the battery is a few years old or hasn’t worked for a few weeks, you may want to rev the engine slightly to speed up the charging process.
Scene changes to the interior of the yellow car with the working battery. We see the woman’s hand start the car. Then she gently pushes the accelerator with her foot in a black shoe a few times.
Text box appears: 4. Start the dead vehicle.
Voiceover: Next, start the vehicle with the dead battery. If it doesn’t start, turn off both cars and check the cable connections. If that doesn’t work, you’ll need a mechanic’s help. We see gloved hands check the cable connections on both cars.
Scene changes to the interior of the blue car with the dead battery. We see the man’s hand turn the key in the ignition. This time, the car starts.
Text box appears: 5. Remove the jumper cables.
Scene changes to show the engines and the jumper cables being removed as described.
Voiceover: Once the dead car is running, it’s time to remove the jumper cables. With the vehicles still running, remove the jumper cables from both batteries in the exact reverse order that you connected them. This will help prevent sparking.
Text boxes appear to indicate the order in which the cables are removed:
- Negative cable from ground connection.
- Negative cable from battery providing jump.
- Positive cable from battery providing the jump.
- Positive cable from previously disabled battery.
Voiceover: If the car with the dead battery starts up, let it run for 20 minutes.
Man’s arm is shown with wrist watch ticking away. We see the hoods on both cars close, and then the cars pull out of the parking lot and drive away.
Voiceover: Remember, a jump start is meant to restart the disabled vehicle, not to recharge the battery. It may be a good idea to put the jumped battery on a battery charger to help ensure that it’s fully charged. If you’re unsure about the long-term health of your battery, consult a mechanic.
For more auto tips, visit allstate.com/blog.