Abstract: A power tool includes a battery-operated power supplying unit adapted to be connected to a battery unit and to generate battery status information, a driving unit adapted to be coupled to a tool bit, a protection unit for making and breaking an electrical circuit between the power supplying unit and the driving unit, a user-actuated unit for enabling operation of the protection unit to make the electrical circuit, and a control unit for enabling operation of the protection unit to break the electrical circuit when the control unit detects an abnormal condition from the battery status information.