Patent ID: 8489347

Claim:
A battery pack monitoring apparatus for monitoring a battery pack constituted of battery blocks connected in series and each including battery cells connected in series, comprising: cell monitoring circuits provided respectively for the battery blocks, each of the cell monitoring circuits including a cell voltage detection circuit to detect cell voltages of the battery cells included in a corresponding one of the battery blocks, and a block voltage detection circuit to detect a block voltage of the corresponding one of the battery blocks; and a control circuit configured to detect states of the battery cells based on the cell voltages and the block voltages transmitted from the respective cell monitoring circuits, wherein a first frequency at which the cell voltage of each of the battery cells is detected is variably set in the cell voltage detection circuit of each of the cell monitoring circuits, and a second frequency at which the block voltage of the battery block is detected is variably set in the block voltage detection circuit of each of the cell monitoring circuits.