A system and method for supplying energy to an implanted medical device is disclosed. The system comprises an internal charger having a first coil, an external charged arranged to wirelessly transmit energy to supply the internal charger with energy, the external charger comprising a second coil, and a wireless feedback system arranged to transmit feedback information from the internal charger to the external charger. The feedback information is based on information obtained from at least one radio frequency identification (RFID) transmitter.