A recharging system and method for an implantable medical device includes: a secondary coil associated with the implantable medical device; an external power source including a primary coil and a modulation circuit operatively coupled to the primary coil, the modulation circuit being capable of driving the primary coil at a carrier frequency when the primary coil is in proximity to the secondary coil and of varying the carrier frequency in response to sensor data received from the implantable medical device; a first sensor associated with the implantable medical device and in communication with the modulation circuit, the first sensor capable of sensing a first condition indicating a need to adjust the carrier frequency during a charging process; and a second sensor associated with the implantable medical device and in communication with the modulation circuit, the second sensor capable of sensing a second condition which is affected by the carrier frequency.