Abstract: In a battery exchange system for facilitating exchange at appropriate intervals of a chargeable battery with another fully charged chargeable battery for charging, a user device having characteristic identification information reads a serial number from a battery when the battery is installed and transmits to a control device correspondence information in which the identification information and the serial number have been placed in correspondence with each other. A charging device reads the serial number from a battery when charging of the battery has been completed and transmits the serial number to the control device. The control device calculates a scheduled charging time of the battery having the serial number that has been transmitted from the charging device based on the time of reception of the correspondence information that was transmitted from user device and, before the calculated scheduled charging time, carries out notification prompting battery exchange.