A method is employed by an electronic device for managing power used by an associated accessory device attached to the electronic device. The method includes applying a current to the accessory device and in response to the applied current, at least one of first and second identifier resistances are identified in the accessory device. The method determines whether the accessory device is connected to a power supply in response to the at least one of identified first and second identifier resistances and applies power to the accessory device in response to a determination the accessory device is not connected to the power supply.