In the field of contactless power transfer for medical devices, more specifically, to contactless power transfer for intra-corporeal medical devices, a rechargeable power supply for an intra-corporeal medical device comprises an implantable power receiving means for wirelessly receiving power, and implantable power storage means. The implantable power receiving means is arranged and configured to receive power from an extra-corporeal power transmitting means for wirelessly transmitting power. The apparatus is particularly useful in the context of minimally invasive procedures.