Reading online/offline

Let me start by saying that I am very thankful for the effort the development team is putting into the Android App.  Having a large chunk of my Library available on my HTC Evo 4G was something I was dreaming about from the first day I got the phone, and the implementation has not disappointed! 

As for feedback that may prove useful to the team, I have noticed some behavior that could probably use some optimizing.  I've read 3 books cover-cover on the app so far, and one thing I have noticed is that battery drain is significantly higher when reading online vs offline.  Without knowing what's going on behind the scenes, I can understand how that might be inevitable if a resource is being downloaded piecemeal while reading (downloading each page at a time or something to that effect).  What bothers me though, is that even if I am reading a resource that is downloaded locally while my internet connection is active, it still seems to give this increased battery drain.  If I shut off my internet connection, I don't see nearly the same amount of drain while using the app. (I would say the battery drain is easily 1.5-2x as fast while online vs offline reading) 

I don't think this behavior is caused by my phone, as I use it rather heavily, and am familiar with the drain caused by 3g/wifi and the various applications I run.    If need be, I can try to scrounge up some cold hard data to help with testing.