US Patent 10039529 Power control arrangements for surgical instruments and batteries

A surgical system is disclosed. The surgical system comprises a surgical device comprising a battery dock. The surgical system further comprises a battery unit comprising at least one battery cell and a battery drain. In a first state, the battery drain is not electrically coupled to the at least one battery cell. In a second state, the battery drain is electrically coupled to the at least one battery cell to discharge the at least one battery cell. The battery drain transitions from the first state to the second state upon attachment of the battery unit to the battery dock.