An exemplary sound processor apparatus included in an auditory prosthesis system includes 1) an interface assembly that includes at least a first contact, 2) a first switchable current source having an output coupled to the first contact of the interface assembly by way of a first data line, and 3) a control module that detects a connection of a battery module to the interface assembly by way of the first contact, enables the first switchable current source while the battery module is connected to the interface assembly, detects a logic level of the first data line while the first switchable current source is enabled and while the battery module is connected to the interface assembly, and identifies, based on the detected logic level of the first data line, a battery type associated with the battery module. Corresponding sound processor apparatuses, systems, and methods are also described.