A wireless charger system for inductively charging a rechargeable battery of an implantable pulse generator (IPG) implanted in a human body is provided. A charging coil in the charger is wirelessly coupled to a receiving coil of the IPG to charge the rechargeable battery. An end-of-charge (EOC) circuit continuously monitors the reflected impedance from a reflected impedance sensor and determines the end of charge when a predetermined pattern of the reflected impedance corresponding to an EOC signal from the IPG is received. Advantageously, receiving the EOC signal through the charging coil eliminates the need to provide a separate communication circuit in the IPG that communicates with the charger.
