Things You'll Need
Instructions
Purchase a 7.2 volt battery charger. The appropriate kind will be listed for use with RC cars and airsoft guns. They're available for from $6 to $30 online.
Remove the battery pack from the gun. Slide it out from the handle and unhook the plastic plug.
Plug the battery into the corresponding plug on the charger. The male end should fit into the female end and lock.
Take the power cord from the charger and plug it into the wall. Wait two to three hours, depending on the model you purchased.
Unplug the device from the wall. Disconnect the battery and attach it securely to the gun once again.