A control circuit for controlling a supply of power to an external electronics module for controlling an implanted device of the user, the control circuit electrically coupled to a switching circuit for controlling an electrical connection between an external power source, a battery, and an external electronics module, the control circuit further electrically coupled to a sensor for sensing at least one from the group consisting of a voltage and a current received from the external power source, the control circuit being configured to control the switching circuit to electrically disconnect the external electronics module from the external power source and electrically connect the external electronics module to the battery in response to a sensed fluctuation of at least one from the group consisting of voltage and current and electrically connect the external electronics module to the external power source and electrically disconnect the external electronics module from the battery when the fluctuation is not sensed.