A method and an apparatus for controlling transmit power of a CR device are provided. The electric tool includes a battery pack, an operator and a controller The battery pack includes a plurality of battery cells and a protection circuit module detects and controls a state of charge and discharge of a plurality of battery cells. Dynamic replay of a telephone conversation is automatically initiated when a conversation experiences insufficient call quality, an interruption to the telephone service is detected, the user is distracted, a displacement of the user’s phone is detected, or the user toggles between listening modes. The second-level cache stores the data for the memory request.