Abstract: A portable digital player-battery includes a digital media player (e.g., an MP3 player) and a battery combined in a single device, in which the device is also designed for use as a power source (e.g., battery) for a wireless communications device like a cellular phone. The portable digital player-battery can operate as a stand-alone MP3 player when separated from the cellular phone, and when connected together with the cellular phone it can operate to stop digital media playback for the duration of a communications session.