A battery and control module to which a powered surgical tool is releasably attached. Internal to the module there is: a cell for energizing the tool； a sensor for monitoring an operational state of the tool； a sensor for monitoring a trigger external to the module； and a control circuit. Based on the signals output by the sensors, the control circuit selectively applies energization signals from the cell to the power generating unit internal to the surgical tool. In some versions of the invention, the trigger is attached to the module.
