A power control loop is established between an external control device and an implantable device so that only the amount of power needed by the implant device to sustain its present operating conditions is transmitted across a transcutaneous transmission link, thereby reducing the amount of power expended by the external control device. In one embodiment, the power control loop is used with a cochlea stimulating system that includes an externally wearable signal receiver and processor (WP) and an implanted cochlear stimulator (ICS). The power control loop is provided between the ICS and the WP such that power delivered to the ICS is precisely controlled in a closed loop manner, with a variable amount of RF energy (power) being transmitted across the transcutaneous link between the WP and ICS. The transmitted RF energy is received by the ICS and is converted to a voltage that is used as a power source within the ICS for stimulating electrode contacts of the ICS. These contacts, when activated, require a certain amount of current that represents a power drain from the power source (i.e., from the voltage derived from the transmitted RF energy). By monitoring the voltage, and transmitting a signal back to the WP from the ICS indicative of the present voltage level, the WP may supply just enough energy to the ICS to maintain the ICS power source at a specified operating voltage level, thereby resulting is less energy expended by the cochlea stimulating system.