How to Jump-Start a Car Safely

Difficulty: Beginner Time: 10–15 minutes

A jump-start uses another car’s battery, or a portable jump pack, to start a car with a dead battery. It takes about 10 minutes once you know the order to connect the cables.

The order matters for safety. The last connection goes to bare metal on the dead car, away from the battery, so any spark happens away from the battery’s gases.

What you'll need

Step by step

1. 1

   Park the cars close, then turn both off

   Park the working car close to the dead one without the cars touching. Turn both off, set the parking brakes, and turn off lights and accessories.

2. 2

   Find the battery posts

   Open both hoods and find the positive (+, often red) and negative (–) posts on each battery. Clean off heavy corrosion if you can so the clamps make good contact.

3. 3

   Red clamp to the dead battery’s positive (+)

   Attach one red clamp to the positive post of the dead battery.

4. 4

   Other red clamp to the good battery’s positive (+)

   Attach the other red clamp to the positive post of the working car’s battery.

5. 5

   Black clamp to the good battery’s negative (–)

   Attach one black clamp to the negative post of the working battery.

6. 6

   Last black clamp to bare metal on the dead car

   Attach the final black clamp to an unpainted metal bolt or bracket on the dead car’s engine or frame, away from the battery. This is the safest final connection.

7. 7

   Start the working car

   Start the good car and let it run for 2 to 5 minutes to put some charge into the dead battery.

8. 8

   Start the dead car

   Try to start the dead car. If it does not start, wait a few more minutes and try again. Do not crank for more than about 10 seconds at a time.

9. 9

   Remove the cables in reverse order

   Once it runs, remove the black clamp from the metal first, then the black from the good battery, then red from the good battery, and red from the jumped car last. Keep the clamps from touching.

10. 10

    Keep it running

    Drive the jumped car for at least 20 to 30 minutes so the alternator can recharge the battery, then get the battery and alternator tested.

Tips

• A portable jump pack lets you start the car by yourself. Follow the pack’s instructions; the clamp order is usually similar.
• If the car starts with a jump but dies again later, the alternator may not be charging. Watch for a battery light on the dash.
• If you hear only rapid clicking even with cables connected, wiggle the clamps for a better grip or clean the terminals.

Parts and tools that may help

Enter your year, make and model on the store's site to see parts that fit your car.

Car batteryPick up or ship · Advance Auto Parts

Jump starter packPick up today · Advance Auto Parts

Battery chargerPick up today · Advance Auto Parts

Battery terminal cleanerPick up or ship · Advance Auto Parts

MultimeterPick up today · Advance Auto Parts

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Frequently asked questions

What order do you connect jumper cables?

Red to the dead battery’s positive, red to the good battery’s positive, black to the good battery’s negative, and the last black to bare metal on the dead car. Remove them in the reverse order.

How long should I leave the cars connected?

Let the working car run for 2 to 5 minutes before trying to start the dead one. A very dead battery may need a little longer.

How long should I drive after a jump-start?

Drive at least 20 to 30 minutes without turning the car off so the alternator can recharge the battery. Then have the battery tested, since it may need replacing.

Why won’t my car start even with a jump?

The clamps may not be making good contact, the battery may be completely failed, or the problem may be the starter, a fuse, or fuel rather than the battery.

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