Green’s Dictionary of Slang

1. (Ling. Fr./Polari) to knock, to strike; thus battery carsey, to knock on a door.

1876		C. Hindley Life and Adventures of a Cheap Jack 832: Occasionally it would happen that the one man who first opened out his masked battery for the purpose of disabling the other, would be the first to fall in the action by a random shot, in the shape of a quartern or two of gin made hot to mix in with the grog instead of water.
2019		P. Baker Fabulosa 289/1: battery to knock down.

2. (W.I.) for two or more men to have sex with the same woman.

1995

Francis-Jackson Official Dancehall Dict. 4: Battery 1. two or more men having sexual intercourse with one female: u. dem battery de gal.