An exemplary cochlear implant system includes 1) a cochlear implant configured to be implanted within a patient, 2) a sound processor configured to be located external to the patient and to direct the cochlear implant to apply electrical stimulation representative of one or more audio signals to the patient, and 3) an implantable battery configured to be implanted within the patient and to provide operating power for the cochlear implant. Corresponding systems and methods are also disclosed.