Use the Proper Voltage
Most car battery chargers are rated for either 12-volt or 6-volt applications, with a button to switch back and forth between the two types. Check your golf cart batteries to determine what voltage they are before you begin. Adjust the car battery charger to the correct voltage.
Hook Up the Battery
Use a wrench to disconnect the battery cables from the battery and then lift the battery out of the golf car. Place the battery on a clear work bench and connect the positive (red) wire to the positive battery terminal and the ground (black) wire to the negative battery terminal.
Watch the Charge
Plug the battery charger into an outlet and then turn it on to begin charging the battery. Make sure to periodically check the charge meter on the charger to assure that the battery does not get over charged. In general, the battery should not sit on the charger for longer than six hours.