A battery monitoring and control integrated circuit is connected to a cell group having a plurality of series-connected single cells for monitoring and controlling the single cells, and includes: a first start input terminal for connecting to a DC signal generation circuit which generates a DC signal based on an AC start signal input from the outside; a start detection unit which detects the DC signal and activates the battery monitoring and control integrated circuit; and a start output unit which outputs the AC start signal to the outside after the activation of the battery monitoring and control integrated circuit.