To jump start a car battery, first you need a set of jumper cables and another vehicle. Once you have those, jumping the battery can be done in a few simple steps: Position the working vehicle close enough together that the jumper cables will reach from one vehicle to another. Make sure both cars are turned off. Open the hoods, locate both batteries and their terminals. On the battery, there will be two terminals: a red one marked with a positive (+) sign and a black one marked with a negative (-) sign. NEVER connect the positive (red) part of the jumper cable to a negative (black) battery terminal, or vice versa. Find a metal area under the hood of the vehicle with the dead battery; you’ll need to connect one of the jumpers to this spot later. Connect a positive (red) jumper cable to the positive (+) terminal of the dead battery. Then connect the other positive (red) jumper cable to the positive (+) terminal of the good battery. Connect a negative (black) jumper cable to the negative (-) terminal of the good battery. Connect the other negative (black) jumper cable to the metal area of the vehicle with the dead battery that you identified in step three. You can use any metal surface as long as it’s not too close to the battery. The side of the car should suffice in most cases. Start the car with the good battery and wait approximately two to five minutes for the other car’s battery to charge. Start the car with the bad battery. If the car starts, remove the jumper cables starting with the negative (black) clamps. If the car doesn’t start, wait a few more minutes for the dead battery to get more juice.