3. (Mil.) (a) Any place where cannon or mortars are mounted, for attack or defense. (b) Two or more pieces of artillery in the field. (c) A company or division of artillery, including the gunners, guns, horses, and all equipments. In the United States, a battery of flying artillery consists usually of six guns.

Maybe we've got it all wrong. Maybe his reference to charging a battery is really a means to replinish spent shells.