PURPOSE: To provide a battery system and a battery pack in which a using condition of a battery can be confirmed.

CONSTITUTION: Every time a battery pack 10 is fitted to an unillustrated charger, a fitting detection switch is turned on, a counting circuit 13 takes a charged number of times N up to the present from a memory part 14, it counts the number as N+1, and it stores the number in the memory part 14 again. When this battery pack 10 is fitted to a video camera 30 and a key 39 is operated, an integrated value of the number of charged times of the battery pack 10 is displayed in an electronic view finder 31 of the video camera 30 through a display generator 34.