Neuromuscular stimulation assemblies, systems, and methods make possible the providing of short-term therapy or diagnostic testing by providing electrical connections between muscles or nerves inside the body and stimulus generators or recording instruments mounted on the surface of the skin outside the body or worn or carried by the patient. The assemblies, systems, and methods include an electrode sized and configured for implantation in tissue, a percutaneous lead electrically coupled to the electrode, a carrier sized and configured to be carried by the patient and to hold a power source, an electronics pod removably carried on-board the carrier and including circuitry configured to generate a stimulation pulse, and an electrode connection element carried on-board the carrier that is electrically coupled to the electronics pod. Instructions furnished by a clinician or caregiver or physician prescribe the release and replacement of a disposable battery according to a prescribed battery replacement regime.