Patent ID: 8174237

Claim:
A battery module comprising: one or more single cells; a voltage detection unit that detects voltages respectively of the one or more single cells; a module monitoring control unit that outputs a signal when each voltage detected by the voltage detection unit becomes equal to a predetermined value; and a communications circuit through which the battery module communicates with a different battery module, wherein the communications circuit comprises: a first series circuit including a first resistor and a second resistor, one end of the first series circuit being connected to a signal input terminal, an opposite end of the first series circuit being connected to a negative electrode of the single cell whose potential is the lowest in the battery module including the communications circuit; a first switch element configured to turn on when a signal of the different battery module is input into a first control terminal from the signal input terminal through the first resistor; a second switch element configured to turn on when the signal of the battery module including the communications circuit is input into a second control terminal; and a second series circuit including a third switch element and a third resistor, the third switch element configured to output a logical sum of the signal of the different battery module, which is output from the first switch element, and the signal of the battery module including the communications circuit, which is output from the second switch element, wherein one end of the second series circuit is connected to a positive electrode of the single cell whose potential is the highest in the battery module including the communications circuit, and an opposite end of the second series circuit is connected to the signal input terminal of the different battery module.