A method includes: (a) receiving identification information of a power storage device that is connected to a charging device, and a value indicating the state of a storage battery included in the power storage device, from at least one of the charging device and the power storage device; (b) associating to each other and storing the identification information of the power storage device and the value indicating the state of the storage battery; (c) prior to charging of the power storage device by the charging device being started, determining the possibility of charging the power storage device by comparing the received value indicating the state of the storage battery with a value indicating a past state of the storage battery that is stored and corresponds to the received identification information of the power storage device; and (d) transmitting information indicating the determined possibility of charging the power storage device to at least one of the charging device and the power storage device.