摘要:
Each of a battery charger and a battery pack has a microcomputer. The respective microcomputers mutually perform data communication while the battery pack is being charged by the battery charger, and confirm an operational state of the microcomputer of the communication counterpart (mutual operation confirmation) based on a result of the data communication. When an abnormality of one of the microcomputers is detected, the other microcomputer executes a predetermined process for stopping charging.