Charging circuit for energy store of a portable electrical device has a first resonance switching circuit with a first receiver coil for receiving an alternating magnetic field which induces an electric voltage in the first coil, and an electrical component connected to a terminal of the first coil. The first coil and the further electrical component determine a resonance frequency (f0) of the first resonance switching circuit, A second resonance circuitry is also provided and has a second receiver coil and a further electrical component which determine a resonance frequency (f1, fn) of the second resonance circuitry. The resonance frequency of the second resonance circuitry is an integer multiple of the resonance frequency of the first resonance switching circuit. Receiver coils of the resonance circuitry are disposed such that during operation they are permeated by the same magnetic field lines of the alternating magnetic field.