Voltage measuring apparatus for assembled battery

A voltage measuring apparatus for measuring an output voltage of an assembled battery in which a plurality of unit cells are connected in series, the voltage measuring apparatus comprising:

• block voltage detection sections, each section measuring a voltage of each block of a plurality of blocks into which the plurality of unit cells are divided;
• a reference voltage output section provided in each of the voltage detection sections to output a reference voltage;
• a difference voltage calculating section which is adapted to calculate a difference voltage between a measured value of the reference voltage measured by one of the block voltage detection sections and a measured value of the reference voltage measured by another of the block voltage detection sections;
• a standard difference voltage storing section for storing therein a standard difference voltage as a standard of the difference voltage between a measured value of the reference voltage measured by said one of the block voltage detection sections and a measured value of the reference voltage measured by said another of the block voltage detection sections;
• a difference voltage determination section which is adapted to determine whether a difference between the difference voltage calculated by the difference voltage calculating section and the standard difference voltage stored in the standard difference voltage storing section exceeds a given threshold voltage or not;
• and
• an abnormality determination section which is adapted to determine that abnormality occurs in the voltage measuring apparatus when the difference is determined as greater than the threshold voltage.