A system including a cordless device having device terminals, a battery pack detachably engageable to the cordless device, and a charger electrically connectable to the battery pack for charging the battery pack. The battery pack has a housing, at least one cell disposed within the housing, pack terminals connectable to the device terminals, and a movable member disposed within the housing. The member is movable between first and second positions to indicate a condition of the battery pack. At least one of the cordless device and the charger have a protrusion for moving the member between the first and second positions.