An implantable medical device (IMD) is configured to provide stimulation therapy to a patient. The IMD includes a rechargeable battery, pulse generating circuitry powered by the rechargeable battery and an inductive coupling element including at least one inductor operative to accept radio frequency (RF) power from an external charger and generate a charging voltage. A temperature sensor is configured to measure a temperature of at least a part of the IMD and output measured temperature data. A waveform generating circuit for converting measured temperature data to a waveform signal for controlling a recharging current for the rechargeable battery. The inductive coupling element is configured to communicate the waveform signal to the external charger.