A power system, for powering a surgical instrument including an end effector and a motor configured to generate at least one motion to effectuate the end effector, includes a primary power source configured to supply a first power to operate the surgical instrument, wherein the primary power source is detachable from the surgical instrument, a secondary power source configured to supply a second power to operate the surgical instrument when the primary power source is detached from the surgical instrument, wherein the secondary power source is rechargeable, and wherein the primary power source is configured to charge the secondary power system, and a power management circuit configured to selectively transmit the first power from the primary power source and the secondary power from the secondary power source to operate the surgical instrument.
