A battery control device having a plurality of cell controllers which are provided corresponding to respective cell groups, are mutually connected in accordance with a predetermined communication order, and detect a state of each unit battery cell of a corresponding cell group, a control circuit which starts or stops a plurality of cell controllers, transmits a communication signal to the highest-order cell controller in a communication order among the plurality of cell controllers, and receives the communication signal from the lowest-order cell controller in the communication order among the plurality of cell controllers, and a first insulating element provided between the control circuit and the highest-order cell controller.