A mobile robotic system includes a charging device and a mobile robot. The charging device is provided with a light emitter and a set of first charging contacts for supplying a charging signal. The mobile robot has a first side provided with a first light sensor, a second side provided with a second light sensor and a set of second charging contacts corresponding to the first charging contacts, a rechargeable battery unit, and a control unit. When charging of the battery unit is intended, the control unit enables movement of the mobile robot until the first light sensor detects light emitted by the light emitter, subsequently enables rotation of the mobile robot until the second light sensor detects the light from the light emitter, and then enables movement of the mobile robot toward the charging device until the first and second charging contacts come into contact.