Apparatus for supplying energy to a medical device implanted in a mammal patient, the medical device comprising an electric circuit adapted to handle different tuned frequency supplies of energy, and an energy supply, the apparatus comprising: a first coil system external to the patient's body for wirelessly transmitting energy for powering the medical device, and a second coil system adapted to, when implanted in the patient's body, receive the wirelessly transmitted energy for powering the medical device, supplying energy to the medical device, when implanted in the patient's body, wherein at least the second coil system comprises two or more, i.e. a plurality of individual coils (60, 61) which in terms of frequency tuned energy supply are adapted to operate at different frequencies and independently of each other, said individual coils comprising electrically conducting wires, wherein at least one of the second coil system's coils includes a toroidal coil having a toroidal axis having the shape of a closed curve, characterized in that at least one of the electrically conducting wires in one of the coils is intermeshed with or entangled with a wire of another of the coils, wherein the at least two coils comprise the same toroidal axis with toroidal helical windings, wherein each of said individual second coil system's coils are supplying energy for powering the medical device, being connected to the electric circuit, said electric circuit handling the different tuned frequency supplies of energy for the energy supply to power the medical device, thereby reducing an amount of energy field the patient has to tolerate at each frequency span, thus allowing higher energy transmission by improving energy transmitting capacity, when implanted and powering the medical device. a first coil system external to the patient's body for wirelessly transmitting energy for powering the medical device, and a second coil system adapted to, when implanted in the patient's body, receive the wirelessly transmitted energy for powering the medical device, supplying energy to the medical device, when implanted in the patient's body, wherein at least the second coil system comprises two or more, i.e. a plurality of individual coils (60, 61) which in terms of frequency tuned energy supply are adapted to operate at different frequencies and independently of each other, said individual coils comprising electrically conducting wires, wherein at least one of the second coil system's coils includes a toroidal coil having a toroidal axis having the shape of a closed curve, characterized in that at least one of the electrically conducting wires in one of the coils is intermeshed with or entangled with a wire of another of the coils, wherein the at least two coils comprise the same toroidal axis with toroidal helical windings, wherein each of said individual second coil system's coils are supplying energy for powering the medical device, being connected to the electric circuit, said electric circuit handling the different tuned frequency supplies of energy for the energy supply to power the medical device, thereby reducing an amount of energy field the patient has to tolerate at each frequency span, thus allowing higher energy transmission by improving energy transmitting capacity, when implanted and powering the medical device.