A voltage detection device for accurately correcting detection errors with
voltage greater than an internal reference voltage. The device includes a
first switch group of switches for obtaining the voltage across a battery
block in a battery pack. A charge-discharge unit has two or more
capacitors connected in series or in parallel. A voltage detector detects
discharge voltage of the capacitors. In a first period, the capacitors
are series-connected and charged with the voltage of the battery block.
In a second period, the capacitors charged in the first period are
series-connected and discharged, and the voltage detector detects the
discharge voltage. In a third period, the capacitors are
parallel-connected and each capacitor is charged with an internal
reference voltage. In the fourth period, the capacitors charged in the
third period are series-connected and discharged, and the detection error
is corrected using the discharge voltage as a reference.