Patent ID: 7668571

Claim:
A speaker system for a mobile device comprising: a first audio processing unit and a first speaker for reproducing an audio signal and outputting the reproduced audio signal, wherein the first speaker is embedded in a main body of the mobile device; a second audio processing unit and a second speaker for reproducing the audio signal and outputting another reproduced audio signal; a first battery embedded within the main body and a second battery within a battery module releasably connected to the main body, wherein the second speaker is embedded in the battery module; a controller positioned in the mobile device and configured to perform operations comprising: determining if the battery module is connected to the mobile device; in response to a determination that the battery module is not connected to the mobile device, controlling the first audio processing unit to transfer the audio signal to the first speaker and controlling the second audio processing unit not to transfer the audio signal to the second speaker; and in response to a determination that the battery module is connected to the mobile device, controlling the first audio processing unit to transfer the audio signal to the first speaker and controlling the second audio processing unit to transfer the audio signal to the second speaker.