Not many things ruin a day faster than having a dead battery when you have appointments to keep. Car batteries seem to know how to obey Murphy’s Law. The car battery corollary would go something like this: If a battery can go dead, it will go dead at the worst possible time. Batteries tend have a sense of humor and believe that it is funny to leave people stranded at malls, in bad neighborhoods, and on interstate highway rest areas. Using jumper cables to start your car is usually the quickest way to get going.
Most drivers need a jump to start their car eventually.
Needing a jump is one of those unfortunate things that almost every driver experiences. Usually, it happens after you have done something to drain the juice from the battery. Leaving the headlights on is one of the surest ways to need a jump. It seems simple enough, but starting a car by using a jump can be extremely dangerous if not done carefully and correctly.
Be very careful when jumping a dead battery in cold weather.
Dead batteries can freeze in temperatures below about 10 or 15 degrees. If you try to jump-start your car without using extreme caution, the battery can explode. You need to let the car that does start run with the cables attached to the dead car for several minutes to warm the cold battery. This could take as much as 20 to 30 minutes in extreme cold. To avoid harm, stand a safe distance from the battery. At least 10 feet is reasonable.
Never make the final ground connection on the battery terminal.
A dead battery may give off gas that will ignite from a spark. To avoid this, never make the last connection on the battery terminal. If you choose not to wear safety goggles when you jumping a vehicle, never stare directly at the battery when making connections. If there is an exposion, you want to make it difficult for any battery acid to hit your eyes.
The front of the cars need to be near one another.
With both cars facing each other and bumpers within about 2 feet of touching, turn off the other vehicle. Using the red cable, connect the two plus sides of the batteries. The ground or black cable should be attached to exposed metal on the motor away from moving parts like fan belts or fans. Make sure the cables are not going to get caught on these. When both cables have been secured at both ends, start the vehicle that is furnishing the power. Allow it to run for about a minute to put some charge into the battery of the dead car.
Make sure that the connections are good between the two cars.
Try starting the car. If it is sluggish, wait another minute or so and try again. If nothing happened, then shut off the first vehicle and try reattaching the cables by unfastening the ground from one car first. Reposition the red cables trying to make sure that they grip the battery terminals securely. Attach the black ones back to the engine. Restart the first car. Attempt to start the car with the dead battery.
If it is sluggish continue to let the other car put power into your battery for another few minutes. Try your headlights. If they burn brightly, you should turn them off and start your car. If it still won’t crank, it might be your starter. As a last resort, you might try turning the first vehicle off and attaching the black cable directly to your negative posts on your battery. Be very careful because the sparks from the final attachment can result in a nasty explosion.
Try to start your car again after you have let the other vehicle charge your battery for a while. It can take 10 minutes or longer. As soon as the car starts, disconnect the cables starting with the black cable. If the car does not crank or try to start at this point, call for profession help or seek other solutions.