The present invention provides a battery that includes a plurality of serially connected battery cells. The battery includes an upper housing and a lower housing. The battery comprises: a wire harness assembly; a middle housing that includes a plurality of cell chambers for accommodating the top sections of the plurality of serially connected battery cells. The lower housing includes a plurality of cell chambers for accommodating the bottom sections of the plurality of serially connected battery cells 102; and the middle housing has a top surface for installing the wire harness assembly (1106) and the plurality of cell chambers beneath the top surface (1102) of the middle housing.