Improved assemblies, systems, and methods provide a stimulation system for prosthetic or therapeutic stimulation of muscles, nerves, or central nervous system tissue, or any combination. The stimulation system includes an implantable pulse generator and a lead sized and configured to be implanted subcutaneously in a tissue region. An external controller includes circuitry adapted for wireless telemetry and a charging coil for generating the radio frequency magnetic field to transcutaneously recharge a rechargeable battery in the pulse generator. Using wireless telemetry, the pulse generator is adapted to transmit status information back to the external controller to allow the external controller to automatically adjust up or down the magnitude of the radio frequency magnetic field and/or to instruct a user to reposition the charging coil, the status information adapted to allow optimal recharging of the pulse generator rechargeable battery.