A surgical instrument, comprising: a surgical end effector (50, 60, 1060) having at least one actuation assembly to effect a surgical procedure when actuated; a handle mechanically coupled with the end effector and having a shell in which there is disposed: an electric motor (120, 210, M) disposed within the shell and having a drive train operatively coupled to the at least one actuation assembly to actuate the at least one actuation assembly when the motor (120, 210, M) is supplied with power; characterized in that the end effector (50, 60, 1060) is a stapling end effector (50, 60, 1060); and the surgical instrument comprises a battery power supply having at least two battery power sources and being disposed within the shell; and a selective switching connection disposed within the shell and electrically coupling the motor (120, 210, M) to the at least two battery power sources to power the motor (120, 210, M) selectively, the switching connection having: a first powered state wherein the motor (120, 210, M) is powered with a first set of battery power sources of the at least two battery power sources to supply the motor with a given power during a first part of a stapling/cutting stroke; and a second powered state wherein the motor (120, 210, M) is powered with a second set of battery power sources of the at least two battery power sources, the second set of battery power sources comprising the first set of battery power sources, to supply the motor with a power greater than the given power during a second part of the stapling/cutting stroke. a surgical end effector (50, 60, 1060) having at least one actuation assembly to effect a surgical procedure when actuated; a handle mechanically coupled with the end effector and having a shell in which there is disposed: an electric motor (120, 210, M) disposed within the shell and having a drive train operatively coupled to the at least one actuation assembly to actuate the at least one actuation assembly when the motor (120, 210, M) is supplied with power; characterized in that an electric motor (120, 210, M) disposed within the shell and having a drive train operatively coupled to the at least one actuation assembly to actuate the at least one actuation assembly when the motor (120, 210, M) is supplied with power; the end effector (50, 60, 1060) is a stapling end effector (50, 60, 1060); and the surgical instrument comprises a battery power supply having at least two battery power sources and being disposed within the shell; and a selective switching connection disposed within the shell and electrically coupling the motor (120, 210, M) to the at least two battery power sources to power the motor (120, 210, M) selectively, the switching connection having: a first powered state wherein the motor (120, 210, M) is powered with a first set of battery power sources of the at least two battery power sources to supply the motor with a given power during a first part of a stapling/cutting stroke; and a second powered state wherein the motor (120, 210, M) is powered with a second set of battery power sources of the at least two battery power sources, the second set of battery power sources comprising the first set of battery power sources, to supply the motor with a power greater than the given power during a second part of the stapling/cutting stroke. a battery power supply having at least two battery power sources and being disposed within the shell; and a selective switching connection disposed within the shell and electrically coupling the motor (120, 210, M) to the at least two battery power sources to power the motor (120, 210, M) selectively, the switching connection having: a first powered state wherein the motor (120, 210, M) is powered with a first set of battery power sources of the at least two battery power sources to supply the motor with a given power during a first part of a stapling/cutting stroke; and a second powered state wherein the motor (120, 210, M) is powered with a second set of battery power sources of the at least two battery power sources, the second set of battery power sources comprising the first set of battery power sources, to supply the motor with a power greater than the given power during a second part of the stapling/cutting stroke. a first powered state wherein the motor (120, 210, M) is powered with a first set of battery power sources of the at least two battery power sources to supply the motor with a given power during a first part of a stapling/cutting stroke; and a second powered state wherein the motor (120, 210, M) is powered with a second set of battery power sources of the at least two battery power sources, the second set of battery power sources comprising the first set of battery power sources, to supply the motor with a power greater than the given power during a second part of the stapling/cutting stroke.