A robot cleaner system and a method for the robot cleaner to return to an external recharging apparatus. The robot cleaner system has an external recharging apparatus including a charging stand having a charging terminal, and a plurality of transmission parts for sending signals having different codes and strengths; a robot cleaner including a rechargeable battery, a connection terminal for connection with the charging terminal to supply power to the rechargeable battery, a receiving part for receiving signals from the plurality of transmission parts, and a control part for controlling a movement of the robot cleaner using the signals received by the receiving part, so that the connection terminal is connected to the charging terminal.