A hand held power tool, comprising: a power tool body: an electric motor held in the power tool body; a universal controller in the power tool body in communication with the electric motor, the universal controller having or being in communication with an electronic component of the power tool that defines a tool type identifier in the power tool body; a battery pack releasably attachable to the power tool body, the battery pack having an on-board electronic identifier; and a trigger switch in communication with the electric motor, characterized in that the trigger switch comprises the universal controller, wherein the electronic component that defines a tool type identifier comprises a resistor held by or in communication with the trigger switch, wherein the universal controller has a plurality of different operational control modes for a plurality of different power tool types in which said battery pack is mounted and a plurality of different battery packs having an on-board electronic identifier with different battery characteristics, and wherein the controller automatically selects an appropriate control mode based on the tool type identifier and the battery pack identifier. a power tool body: an electric motor held in the power tool body; a universal controller in the power tool body in communication with the electric motor, the universal controller having or being in communication with an electronic component of the power tool that defines a tool type identifier in the power tool body; a battery pack releasably attachable to the power tool body, the battery pack having an on-board electronic identifier; and a trigger switch in communication with the electric motor, characterized in that the trigger switch comprises the universal controller, wherein the electronic component that defines a tool type identifier comprises a resistor held by or in communication with the trigger switch, wherein the universal controller has a plurality of different operational control modes for a plurality of different power tool types in which said battery pack is mounted and a plurality of different battery packs having an on-board electronic identifier with different battery characteristics, and wherein the controller automatically selects an appropriate control mode based on the tool type identifier and the battery pack identifier. an electric motor held in the power tool body; a universal controller in the power tool body in communication with the electric motor, the universal controller having or being in communication with an electronic component of the power tool that defines a tool type identifier in the power tool body; a battery pack releasably attachable to the power tool body, the battery pack having an on-board electronic identifier; and a trigger switch in communication with the electric motor, characterized in that the trigger switch comprises the universal controller, wherein the electronic component that defines a tool type identifier comprises a resistor held by or in communication with the trigger switch, wherein the universal controller has a plurality of different operational control modes for a plurality of different power tool types in which said battery pack is mounted and a plurality of different battery packs having an on-board electronic identifier with different battery characteristics, and wherein the controller automatically selects an appropriate control mode based on the tool type identifier and the battery pack identifier.