There is a safe way to hook up battery jump-start cables. Since batteries contain sulfuric acid, they can emit fumes that are flammable. A slight spark from connecting jumper cables improperly can ignite the fumes and cause the battery to explode. Great care should be adhered to when hooking up jump-start cables to a dead battery.
Park the assisting (booster) vehicle close enough so the jump-start cables can properly reach each battery of the respective vehicles. Turn off the booster vehicle, and make sure there is nothing on (such as lights, radio, blower fan) in either vehicle.
Separate the jump-start cable clamps from each other, and spread the cables out on the ground.
Attach a red clamp to the positive battery terminal (red wire and marked with a "+" on the housing of the battery) of the dead battery. Isolate the black clamp on that side, and make sure it does not come into contact with the battery or anything metal.
Attach the other red clamp of the jump-start cable to the positive terminal battery of the booster vehicle.
Connect the black clamp of the jump-start cable to the negative battery terminal (black wire and marked with a "-") of the battery on the booster vehicle.
Attach the last remaining black clamp (on the vehicle with the dead battery) to an unpainted engine mount, bolt, or bracket as far away from the dead battery as the cable will allow. Be sure that this clamp and any of the cable wires cannot come into contact with any moving engine parts once the vehicles are running.
Start the engine of the booster vehicle, and allow a few minutes of idling to charge the dead battery of the other vehicle. Start the vehicle with the dead battery. Shut off the booster vehicle only, but allow the other car to charge its own battery.
Disconnect the jump-start cables in the exact reverse order in which you attached them, starting with the negative clamp of the car with the dead battery. Allow the compromised vehicle to run for a while in order to restore charge to the battery.
