Charging a dead car battery is a fairly simple process, but you want to make sure you're doing it safely. Batteries, dead or not, have volatile acid inside that create flammable gases. These gases can ignite and explode in the presence of sparks. While this is a rare occurrence, it can happen, so caution is recommended.
Open the hood. Place the battery charger in a safe place where it will not come into contact with any moving parts of the engine once it is running.
Put on the safety glasses. Do not plug the battery charger into the electrical outlet or the extension cord (if you're using one) at this time.
Attach the red clamp of the battery charger to the positive battery terminal. This is the red cabled terminal on the battery with the "+" insignia stamped on the battery housing.
Attach the black clamp of the battery charger to the negative battery terminal. This is the black cabled terminal on the battery with the "-" insignia stamped on the battery housing.
Adjust the dials and or buttons on the battery charger to accommodate the car battery. Choose 12 volts for auto battery if it's an option on your charger. Choose non-deep cell or non-deep cycle battery if there is an option for this on your charger. The amp setting is going to depend on how quickly you want the battery to charge. The lower the amp setting, the longer the charge will take. Many battery manufacturers recommend a low amp charge to effectively restore life to a battery, however, this is not always viable and many battery chargers come with a high amp or "start" setting to charge the battery quickly or immediately if you're in a hurry. The type of charger you have will dictate how many amp settings you have and what you'll be able to select. A low or medium selection is safe and will not overheat the battery.
Plug the battery charger into the electrical outlet or extension cord. Again, depending on the type of battery charger you have, power may start flowing when you plug it in or you may have to set a timer option on the charger. If you're using a timer, set it to coincide with the amp setting you chose. The charger will shut off automatically when the time expires.
Be sure that the clamp wires, the charger itself, and the electrical cord are away from any moving engine parts.
Try to start the car. If it does not start, it may need more time or a higher amp setting to charge more quickly. Make any necessary changes, but do not touch the clamps of the charger to the battery while it is plugged in. Once the car is started up, leave it running.
Unplug the battery charger or turn the timer switch to off and then unplug it. This kills the power to the battery charger and makes it safe to disconnect the charger at the battery post. Disconnect the negative clamp first and then the positive. Be careful with any dangling wires from the charger. Remove the charger and close the hood of the car.
