The battery run-time of the MID depends on how you operate your MID and your hardware settings.
 
Internet connection: Up to 3 hrs.
Video Playback: Up to 2 hrs.
Audio Playback: Up to 4 hrs.
3.5G connection: Up to 2 hrs.
Other applications: Up to 4 hrs.
Standby time: Up to 24 hrs.