A system for supplying energy to an implantable medical device when implanted in a patient's body can comprise an internal charger arranged to be implanted in the patient's body, the internal charger comprising a first coil. The system can further comprise an external charger arranged to wirelessly transmit energy to supply power to the internal charger, using a second coil. The system also comprises a wireless feedback system arranged to transmit feedback information from the internal charger to the external charger. The feedback information is based on information from at least one Radio Frequency Identification (RFID) transmitter. Hereby a user of the system can optimize the position of the external power supply in relation to the internal power supply based on the received feedback information. This in turn will result in a better and more robust energy transfer to the implanted medical device.
