A surgical instrument (1), comprising a surgical end effector (60) having an actuator (180) to effect a surgical procedure when actuated; an electric motor (120) being operationally connected to said end effector (60) to operate said actuator (180); a power supply (600) electrically connected to said motor (120) and actuating said actuator (180) when said power supply (600) powers said motor (120), said power supply (600) having at least one battery cell with a given rated power for an operating period of greater than 15 seconds; and said motor (120) and said power supply (600) being configured to utilize said battery cell at a power greater than said given rated power.