Charging Batteries A person can usually tell that their car battery is dead when they go to turn on their car and nothing happens. There is usually no sound and no engine turnover. A battery may go dead if you keep your headlights on or play the radio for a long time while the engine is not running. An old battery might not even start up if it is really cold out. If the battery is dead, then you can't start the engine. You could be able to restore power to your battery by using jumper cables to connect it to a working battery in another car. It is always a good idea to keep jumper cables in the trunk of your car.
Booster cables (12V, 50A, 3mm², 3.5m)
Battery
Jumper cable connected to positive postJump-starting your battery is the most common way to recharge it. To do this, you need another car with a working battery that is the same voltage as yours and a pair of jumper cables. Before you do this, you would want to make sure that the battery fluid is not frozen or the level of the fluid is low. If this is the case, then you wouldn't want to try and jump-start your car because it could explode.
In order to jump-start your car properly, you would first need to position the cars so the cables can reach between the two batteries. But make sure that the cars are not touching. The ignition and the electrical equipment in both cars must be turned off. Then you have to shift both cars into Park or Neutral, and put their parking brakes on. You want to double check that both the cars have the same amount of voltage (usually 12 volts).
You should remove cell or vent caps if the battery has them. Then check...