A dead car battery can happen to anyone for plenty of reasons: accidentally leaving the headlights on, battery wear and tear, or freezing winter temperatures. No matter why your battery drained, you can easily revive it by hooking it up to a working vehicle with jumper cables. Before your car can hit the road again, the battery needs enough of a boost to crank the starter.

Wondering how to connect jumper cables safely? Here is everything you need to know to get back on the road.

Step by Step Guide to Using Jumper Cables

1. Park the booster vehicle next to the car with the dead battery. Position the cars close enough for the jumper cables to reach comfortably without stretching, but make sure the vehicles do not touch each other.

2. Turn off all accessories in both vehicles. Shut off the headlights, hazard lights, radios, climate control, and interior dome lights.

3. Turn off both ignitions. Set the parking brake on both cars. Put automatic transmissions into “Park” and manual transmissions into neutral.

4. Identify the positive and negative terminals on both batteries. The positive terminal is almost always marked with a plus sign (+) and often features red wiring or a red plastic cover. The negative terminal is marked with a minus sign (-) and usually features black wiring.

5. Keep the cable clamps separated. Never allow the red and black clamps to touch each other while connected to either battery, as this will cause dangerous sparks and short circuits.

6. Attach one red clamp to the positive (+) terminal of the dead battery. Make sure the clamp has a firm, solid grip on the metal terminal post.

On some modern vehicles, you may need to flip open or unclip a plastic protective cover over the positive terminal before attaching the clamp.

7. Attach the other red clamp to the positive (+) terminal of the donor battery. Verify that the clamp sits securely so it will not slip loose when the engine vibrates.

8. Connect one black clamp to the negative (-) terminal of the donor battery.

9. Connect the remaining black clamp to an unpainted metal surface on the car with the dead battery.

A clean, unpainted bolt or bracket on the engine block works best as a grounding point. Ensure the clamp grips tightly so it stays put once the engine starts vibrating.

While you can technically connect the second black clamp directly to the dead battery’s negative terminal, doing so can generate a spark that might ignite hydrogen gas emitted by the battery. Grounding the clamp on unpainted engine metal is significantly safer.

Double-check that all cables hang safely away from belts, cooling fans, pulleys, and any other moving parts under the hood.

10. Start the donor car and let it run idle for a few minutes. This gives the dead battery time to absorb an initial charge before you attempt to crank the dead vehicle.

11. Turn the ignition on the dead car. Once the engine fires up successfully, disconnect the cables in the exact reverse order:

• The grounding black clamp on the dead vehicle (engine block).
• The black clamp on the donor battery’s negative terminal.
• The red clamp on the donor battery’s positive terminal.
• The red clamp on the revived battery’s positive terminal.

Pro Tips for a Smooth Jump Start

Some car manufacturers cover the entire battery under a large plastic shroud that must be pulled off before you can hook up clamps. Most clips can be popped loose by hand or with a flathead screwdriver. It is always wise to keep a basic screwdriver in your glove box or trunk organizer just in case.

Once the dead car starts running, do not shut off the engine. Keep the vehicle running or drive it around for at least 15 to 20 minutes so the alternator has enough time to recharge the battery fully. Turning it off immediately could leave you stranded again, requiring another jump start.