A method for controlling an implantable medical device is disclosed. In one embodiment, a voltage of a power source within the implantable medical device is monitored. If this voltage is above a first threshold, the implantable medical device enables the following functions: it listens for a first type of telemetry from a first external component; it listens for a second type of telemetry from an external charging component; and it provides stimulation to device electrodes using the power source. By contrast, if the power source voltage falls below the first threshold, the implant discontinues listening for the first type of telemetry from the first external component and discontinues providing stimulation to device electrodes using the power source, but continues to listen for the second type of telemetry.