A battery pack of one aspect of an embodiment of the present disclosure comprises a battery, a control unit, a pair of external terminals, a first current cut-off unit, and a second current cut-off unit. The control unit determines whether the first current cut-off unit and the second current cut-off unit are normal or abnormal when neither charge nor discharge of the battery is performed. When the first current cut-off unit and the second current cut-off unit are both normal, the control unit turns the first current cut-off unit and the second current cut-off unit to an energized state. When at least one of the first current cut-off unit and the second current cut-off unit is abnormal, the control unit turns the first current cut-off unit or the second current cut-off unit to a cut-off state.