Things You'll Need
Instructions
Order a 7.2-volt battery charger. Hobby and paintball suppliers sell several different varieties, as will some hobby stores. Prices vary, but you should be able to find one for $20 or less.
Take the NiMH battery pack out of the gun. Pull it out through the handle and unplug it.
Connect the battery to your charger. Press the two corresponding ends together until they click into place.
Plug the charger power supply into a wall outlet. Allow the battery to charge for several hours, or the amount directed by your charger.
Remove the charger from the wall. Disconnect the battery and plug it back into the gun.