Patent ID: 8629656

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; a control section for measuring a voltage of each cell block of the one or the plurality of cell blocks to detect an abnormality of a cell block on the basis of a measurement result; and a charge and discharge switch directly coupled to the control section for controlling a charge and discharge current for the cell blocks on the basis of control performed by the control section, wherein the control section calculates a time differential of the voltage for the one or the plurality of cell blocks on the basis of the measured voltage; extracts a first time differential which is maximum and a second time differential which is minimum from the time differentials of the voltage for the one or the plurality of cell blocks; and determines that a cell block corresponding to the second time differential is abnormal in a case where a difference between the first time differential and the second time differential is less than a prescribed value, wherein the abnormality of the cell block includes a short-circuiting in the battery cells.