Cordless energy-based surgical instruments including reusable and disposable portions

A surgical instrument, comprising:

• a housing including a sealed compartment and an exposed shell, the housing configured to withstand autoclave sterilization and configured to releasably engage an elongate assembly including an end effector;
• electronics sealed within the sealed compartment of the housing, wherein the sealed compartment protects the electronics to enable autoclave sterilization of the housing without damaging the electronics;
• and
• an activation assembly operably coupled to the exposed shell of the housing, the activation assembly including an activation button movable relative to the housing between an un-activated position and at least one activated position, and one or more electrical switches configured to detect activation of the activation button and, the at least one electrical switch electrically coupled to the electronics and configured to transmit the detected activation to the electronics,
• wherein, with the elongate assembly engaged with the housing, the electronics, in response to receipt of the detected activation, are configured to energize the end effector of the elongate assembly to treat tissue with energy.