A battery management device comprising: a first integrated circuit that is provided corresponding to a first battery cell group electrically connected to one side of an interruption mechanism for interrupting an electric connection, and is configured to measure respective voltages of a plurality of battery cells constituting the first battery cell group; a second integrated circuit that is provided corresponding to a second battery cell group electrically connected to the other side of the interruption mechanism, and is configured to measure respective voltages of a plurality of battery cells constituting the second battery cell group; a signal transmission path configured to transmit a communication signal between a transmission terminal (TxD) of the first integrated circuit and a transmission terminal (TxD) of the second integrated circuit; and a connection circuit that AC-couples a coupling target terminal (GND, Vcc) of the first integrated circuit, which is electrically connected to any of the battery cells of the first battery cell group, to a coupling target terminal of the second integrated circuit which is electrically connected to any of the battery cells of the second battery cell group, through a capacitor, characterized in that: an electric potential of the coupling target terminal (GND, Vcc) of the first integrated circuit, being a reference electric potential of the transmission terminal of the first integrated circuit, is configured to be used as a reference electric potential of the communication signal that is transmitted as the signal to the second integrated circuit through the signal transmission path, and an electric potential of the coupling target terminal of the second integrated circuit is a reference electric potential of the receiving terminal of the second integrated circuit that receives the communication signal transmitted from the first integrated circuit through the signal transmission path. a first integrated circuit that is provided corresponding to a first battery cell group electrically connected to one side of an interruption mechanism for interrupting an electric connection, and is configured to measure respective voltages of a plurality of battery cells constituting the first battery cell group; a second integrated circuit that is provided corresponding to a second battery cell group electrically connected to the other side of the interruption mechanism, and is configured to measure respective voltages of a plurality of battery cells constituting the second battery cell group; a signal transmission path configured to transmit a communication signal between a transmission terminal (TxD) of the first integrated circuit and a transmission terminal (TxD) of the second integrated circuit; and a connection circuit that AC-couples a coupling target terminal (GND, Vcc) of the first integrated circuit, which is electrically connected to any of the battery cells of the first battery cell group, to a coupling target terminal of the second integrated circuit which is electrically connected to any of the battery cells of the second battery cell group, through a capacitor, characterized in that: an electric potential of the coupling target terminal (GND, Vcc) of the first integrated circuit, being a reference electric potential of the transmission terminal of the first integrated circuit, is configured to be used as a reference electric potential of the communication signal that is transmitted as the signal to the second integrated circuit through the signal transmission path, and an electric potential of the coupling target terminal of the second integrated circuit is a reference electric potential of the receiving terminal of the second integrated circuit that receives the communication signal transmitted from the first integrated circuit through the signal transmission path. an electric potential of the coupling target terminal (GND, Vcc) of the first integrated circuit, being a reference electric potential of the transmission terminal of the first integrated circuit, is configured to be used as a reference electric potential of the communication signal that is transmitted as the signal to the second integrated circuit through the signal transmission path, and an electric potential of the coupling target terminal of the second integrated circuit is a reference electric potential of the receiving terminal of the second integrated circuit that receives the communication signal transmitted from the first integrated circuit through the signal transmission path.