摘要 |
For the measurement of the voltage of each block which constitutes a battery pack with different timings, a voltage (V) and current (I) every block the current of which is measured at the same timing as the voltage is measured are read (S100-S108) and an inner resistance (R) is derived from the temperature (T) of the assembled battery (S110, S112). A value of the difference (IN - IN+1) of two currents corresponding to two voltages of respective blocks of a plurality of battery blocks multiplied by the inner resistance (R) of the battery pack is added to the difference (VN - VN+1) of two voltages to calculate the voltage difference DELTA V (S116). When the maximum value DELTA Vmax of the calculated voltage difference DELTA V exceeds the threshold value Vref, the state is judged to be an overdischarge (S122, S124, S128). <IMAGE> |