1. The act of borrowing fresh batteries from one working device to power that of another. 2. The act of swapping the good batteries from a working device with the dead batteries of another device in order to use the device that originally contained the dead batteries.
Most often practiced with AA or AAA batteries in remote controls. 9 volt battery cannibalism is extraordinarily cruel due to the expense and lack of extra 9 volt batteries in the home.
When Kyle swapped the good batteries from the living room TV remote with the dead ones from his bedroom remote, he was practicing Battery Cannibalism.