Patent ID: 8917059

Claim:
An inter-module voltage balance correcting circuit of a power storage system including a plurality of storage modules connected in series, each of the storage modules including a plurality of storage cells connected in series, the inter-module voltage balance correcting circuit comprising: a resistance voltage dividing circuit that equally divides a series voltage across a first storage module and a second storage module connected in series; a pair of transistors that are turned ON/OFF in a complementary manner based on a voltage that appears between an intermediate connecting point between the first and second storage modules and a voltage dividing point of the resistance voltage dividing circuit, the pair of transistors having commonly connected bases and commonly connected emitters; and a resistive element whose one end is connected to the commonly connected bases and whose other end is connected to the commonly connected emitters, the one end of the resistive element being further connected to the voltage dividing point, the other end of the resistive element being further connected to the intermediate connecting point, one of the pair of transistors being turned ON in a case where a dividing voltage that appears at the voltage dividing point becomes higher than an intermediate voltage that appears at the intermediate connecting point and causing a bypass discharge resistive element to be connected to a storage module situated at a positive side of the series-connected storage modules, the other of the pair of transistors being turned ON in a case where the dividing voltage becomes lower than the intermediate voltage and causing a bypass discharge resistive element to be connected to a storage module situated at a negative side of the series-connected storage modules.