Disclosed herein is a battery. The battery includes a contactless communication control block configured to execute contactless communication as a transponder and a reader/writer which are based on electromagnetic induction. The battery further includes an antenna configured to execute the contactless communication as the transponder; and an antenna configured to execute the contactless communication as the reader/writer. The battery further includes a battery control block configured to control a charge operation of a cell block. The contactless communication control block communicates, in a contactless manner, a charge state of the cell block supplied from the battery control block.