A management device is provided with an acquiring unit for acquiring the amount of variation between the voltage of a power storage element when conduction of power is suspended from a state in which power is being conducted to the power storage element and the voltage when a period has elapsed, and a determination unit for determining whether the amount of variation is included in a second range that corresponds to a first range in which the voltage difference between each power storage amount-voltage characteristic during charging and discharging for the same power storage amount is less than another range.