Patent ID: 8049509

Claim:
A battery information acquiring apparatus that acquires battery information of a battery cell in a battery pack including a plurality of the battery cells connected in series or in parallel and transmits the battery information to a management unit that manages a state of the battery pack via an antenna, comprising: a voltage acquiring unit configured to acquire an inter-terminal voltage of the battery cell; a battery information acquiring circuit configured to acquire battery information of the battery cell, the battery information acquiring circuit being supplied with the inter-terminal voltage acquired by the voltage acquiring unit as a first power supply voltage; a radio circuit configured to transmit a signal of the battery information to the management unit via the antenna, the radio circuit being supplied with the inter-terminal voltage acquired by the voltage acquiring unit as a second power supply voltage; a rectification circuit configured to receive a radio signal from the management unit via the antenna and rectify the received radio signal to generate a DC voltage; and a control circuit configured to control supply of the first and second power supply voltages to the battery information acquiring circuit and the radio circuit, the control circuit being supplied with the DC voltage generated by the rectification circuit as a third power supply voltage, wherein the control circuit includes: a first command receiver configured to receive a first command signal indicating whether or not to supply the first power supply voltage to the battery information acquiring circuit, from the management unit via the antenna; a second command receiver configured to receive a second command signal indicating whether or not to supply the second power supply voltage to the radio circuit, from the management unit via the antenna; a first controller configured to control supply of the first power supply voltage to the battery information acquiring circuit according to the first command signal; and a second controller configured to control supply of the second power supply voltage to the radio circuit according to the second command signal.