Energy changes from one form to another by transferring through things. When it is still in the battery it is called stored chemical energy. When it transfers through to something it is called electrical energy. When my teams rechargeable battery was dead, we charged it. So that we would not get electrocuted, we unplugged it before we put the two battery's in. After we charged our battery for three minutes we put the two battery's in the flashlight and the light stayed lit for six minutes and five seconds.