A cordless cautery and cutting surgical device includes a modular battery and a surgical handle. The battery has a cordless radio-frequency-signal-generation assembly generating an output radio-frequency signal and a first selectively removable connector part. The surgical handle has a first handle body portion with a bipolar cautery and cutting end effector. The end effector has jaws with bipolar contacts and a cutting blade disposed between the jaws. The handle has a second body portion connected to the first body portion, defines therein an aseptically sealable battery-holding compartment selectively exposed to the environment and removably holding therein the battery, and a second selectively removable connector part operable to removably hold the first connector part thereto. The second connector part has conductors electrically connecting the RF assembly to the bipolar contacts for supplying the radio-frequency signal to the bipolar contacts when the first and second connector parts are removably secured together.