I must admitt, I havnt really wore down my battery yet. I usually put it back in the cradle with 70 - 80 % battery left. Today I had it play mp3s all day and ran it down to 15% and charged it back up only to have it read 2h 42m again. I'll run it down again tomorrow as maybe it'll take a few times for it to learn.
I went to their web site and it turns out this is a FAQ
http://www.omegaone.com/FAQ.html#BB1
Also learned they offer free alternate sound files:
-Alternate female voice
-Simpsons sound files
-South Park sound files
-Star Trek sound files
-Star Trek: The Next Generation sound files
go to
http://www.omegaone.com/PocketPC/BPSounds.html