Patent ID: 8203306

Claim:
A battery pack comprising: one or a plurality of cell blocks in which one or a plurality of secondary battery cells are connected at least are of in series and in parallel; and a control section for measuring a voltage and a charge current of the one or the plurality of cell blocks to detect an abnormality of a cell block on the basis of a measurement result, wherein the control section calculates time differentials of the voltage and the charge current and second-order time differentials of the voltage and the charge current for the one or the plurality of cell blocks on the basis of the measured voltage and charge current; determines that a cell block is abnormal in a case where the time differential of the voltage is less than a prescribed value, the second-order time differential of the voltage is less than the prescribed value, and the second-order time differential of the charge current is not less than the prescribed value; and determines that a cell block is abnormal in a case where the time differential of the charge current is more than the prescribed value, the second-order time differential of the charge current is more than the prescribed value, and the second-order time differential of the voltage is not more than the prescribed value.