Battery is one of the plant workers. Unlike the other workers, he actually volunteered at the plant for the opportunity to tinker with the unique machinery. He's a little bored now, but he doesn't have any real incentive to leave. The other workers, who are not there voluntarily, think Battery is weird and stupid for sticking around. Then again, he is a tribal.
Battery has not appeared nor is he mentioned in any published game. He was to appear only in Van Buren, the canceled Fallout 3 by Black Isle Studios. It is not certain if he will appear in any future Fallout game.