A multi-series battery control system comprises battery cell groups each having a plurality of serially connected battery cells, a plurality of integrated circuits each disposed in correspondence to the battery cell groups and a battery control device that exchanges signals with the individual integrated circuits. The integrated circuits are sequentially connected with a transmission path, and a signal from the battery control device is then repeatedly input and output in sequence from the first to last integrated circuit. The signal output from the integrated circuit at the last position is transmitted to the battery control device. Each integrated circuit includes an address setting means that receives a message unique to the integrated circuit from the battery control device, writes over an initialized address of the integrated circuit with the message and alters the message to a message with which an initialized address of another integrated circuit cannot be overwritten in a step assigned with an ordinal number matching the position of the integrated circuit with regard to the connection order.
