Voltage monitoring apparatus

A battery system comprising:

• a battery pack that is configured by at least one battery cell;
• and
• a voltage monitoring apparatus that includes:
• a capacitor circuit including at least one capacitor;
• an input-side switch group that includes a plurality of input-side switches connected to at least one pair of electrode terminals of at least one battery cell, the input-side switch group applying voltage to a pair of terminals of the at least one capacitor;
• a voltage detection circuit that includes at least one pair of voltage sensing terminals connected to each of the terminals of the at least one capacitor, the voltage detection circuit detecting a potential difference across the at least one pair of voltage sensing terminals;
• an output-side switch group that includes a plurality of output-side switches connected to the terminals of the at least one capacitor, the output-side switch group applying voltage across the terminals of the at least one capacitor to the at least one pair of voltage sensing terminals;
• switch control means for controlling each of the plurality of input-side switches and each of the plurality of output-side switches;
• failure detecting means for detecting, on the basis of the voltage detected by the voltage detection circuit when one of the output-side switches is turned on, an on-failure of at least one of the remaining output-side switches which should not be turned on;
• an impedance circuit that is connected to each of the at least one pair of voltage sensing terminals;
• and
• a stabilizing power circuit that is connected to each of the at least one pair of voltage sensing terminals via the impedance circuit and stabilizes voltage of each of the at least one pair of voltage sensing terminals.