To provide a method for controling a battery pack, which is not abnormally heated due to failure of ohmic-resistance heating type fuse.

The battery pack A comprises: a switching element SWH which is switched from off to on when a battery pack A containing a secondary battery 1 comes into an abnormal state; a heating resistor R which is connected in series to the battery 1 and the switching element SWH and through which a current flows when the switching element SWH turns it on; and a resistance heating type fuse 10 which is arranged at a position where it is heated with the heating resistor R which the current flows, is connected in series to the battery 1, and comprises a fuse H that shields a current that flows the battery when fused and cut by the heating resistor R that becomes hot when the current flows. The switching element SWH is changed from off to on during a specified period of time when it comes into an abnormal state.