Battery management device and power supply device

A battery management device comprising:

• a plurality of cascade-connected voltage detection ICs (Integrated Circuits) for detecting each voltage of a plurality of battery cells connected in series and constituting an assembled battery, through a plurality of voltage detection lines;
• power sources receiving power from the assembled battery, for supplying power to the plurality of the voltage detection ICs;
• communication lines connecting between the plurality of the voltage detection ICs;
• a controlling circuit connected to at least one of the plurality of the voltage detection ICs through a communication line;
• a dummy resistor connected to each of one or more of the voltage detection ICs which are not directly communicated to the controlling circuit out of the plurality of the voltage detection ICs:
• and
• a switch turning on or off current supply through the dummy resistor,
• wherein in adjacent two of the voltage detection ICs, a ground electric potential of the higher voltage side voltage detection IC and an electric potential of the power source of the lower voltage side voltage detection IC are connected, and the connected node and a node connected between the battery cells corresponding to the connected node are connected through the voltage detection line, and
• in the plurality of the voltage detection ICs, the at least one of the voltage detection ICs, which are directly communicated to the controlling circuit, is not connected to the dummy resistor and the switch turning on or off current supply through the dummy resistor.