Remaining capacity equalizing device and method, and remaining capacity equalizing device set

A remaining capacity equalizing device is provided having an inductance connected to a reference node of a battery pack and first and second switching elements. A first closed circuit is formed through selecting sequentially a first switching switch from a first switching switch group that is connected to the high-voltage side of the reference node. A second closed circuit is formed by selecting sequentially a second switching switch from among a second switching switch group that is connected to the low-voltage side of the reference node. The first and second switching elements are turned ON/OFF alternatingly for each combination of first and second closed circuits so that, during a specific interval, the ratio of the conductive times of the first and second switching elements is the inverse of the ratio of the numbers of storage cells in the first and second closed circuits.