I've been using mine solid since 9:00am this morning Robin- and it still reports 35% battery left. That's 11 hours and counting! The LiPo batteries in the new MacBook and these units are phenomenal, so I don't think that it's a design omission. I don't think that I'd ever need more than this.
Gee, I really am on the defensive today aren't I? LOL !!
I guess that I can speak first-hand of it now, so please excuse my enthusiasm.