Battery voltage monitoring apparatus

A battery voltage monitoring apparatus monitoring a voltage of an assembled battery, the assembled battery including a plurality of battery cells, the battery voltage monitoring apparatus comprising;

• a first voltage sensor module that monitors voltages of a plurality of battery cells arranged at a high voltage side;
• and
• a second voltage sensor module that monitors voltages of a plurality of battery cells arranged at a low voltage side,
• wherein the second voltage sensor module comprises a voltage sensor that is connected to a terminal and detects a voltage of a battery cell connected to the terminal, the terminal being supplied with a power source potential of the second voltage sensor module,
• wherein the voltage sensor comprises a comparator including a first comparator terminal and a second comparator terminal, the first comparator terminal being supplied with a voltage according to the voltage of the battery cell, the second comparator terminal being supplied with a reference voltage, and
• wherein the comparator has a hysteresis characteristic and the hysteresis characteristic of the comparator is set according to an output of the comparator evaluated by comparing the reference voltage with a voltage of the terminal which is determined based on the voltage of the battery cell and the power source potential.