How to Jumpstart an Automotive Battery

Safety Tips

Batteries contain explosive gases. Don't strike a light while jumpstarting a car and don't try to jumpstart a damaged battery. Do not jumpstart a battery that is frozen.

Batteries contain sulfuric acid. If any gets on your skin or in your eyes, flush with water and get medical help immediately. We recommend that you wear eye protection, such as ANSI* approved safety glasses or goggles or a face shield.

Never lean over the battery when making a connection or disconnection.

Before you begin, you'll need...

A set of jumper cables
A vehicle with a good battery that is the same voltage as yours
To know the difference between the negative and positive battery terminals and the negative and positive clamps of the jumper cables. Positive is indicated by a (+) sign, the words "POS" and the color red; negative is marked by a (-) sign, the words "NEG" and the color black. The colors may vary but are red (+) and black (-) in most instances.

Jumpstarting

1.Pull the cars next to each so they're not touching and turn off both ignitions.
2.Connect the positive clamp of the jumper cable to the dead battery's positive terminal.
3.Connect the other positive clamp of the cable to the positive terminal of the battery in the starting vehicle.
4.Connect the negative clamp of the cable to the negative terminal of the battery in the starting vehicle.
5.Connect the other negative clamp of the cable to the vehicle's engine block, or other metal surface of the car--away from the battery. This metal surface is exclusive of the carburetor or tubing on the car with the discharged battery. This serves as your ground or connection point.
6.Make certain all cables are clear of fan blades, belts and other moving parts of both engines and that everyone is standing away from the vehicles. Start the car of the battery providing the jump start; then try to start the car with the dead battery.

If the car starts, allow the engine to return to idle speed, then remove the cables in the reverse order that you put them on.

Remove the negative clamp on the ground of the car that needed the jump
Remove the negative clamp on the assisting vehicle
Remove the positive clamp from the assisting vehicle
Remove the positive clamp from the formerly stalled vehicle

If the car doesn't start, wait a few moments and try again. If it still doesn't start, you probably need a new battery.

 * ANSI – American National Standards Institute
 These instructions are provided courtesy of the Battery Division of Johnson Controls, Inc.
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