An apparatus includes a power adapter having a housing and a circuit at least partially disposed in the housing. The housing is configured to be coupled to an implantable device for disposition in a body. The circuit is configured to be electrically connected to a power circuit of the implantable device when the housing is coupled to the implantable electrical conductor. When the housing is coupled to the implantable electrical conductor and implanted in a body, the circuit is configured to (1) receive, transcutaneously from a power supply, a first energy, (2) convert the first energy to a second energy, and (3) transfer, to the implantable device, the second energy such that the second energy powers the implantable device.