I've been looking at color e-book readers for the past few weeks now, and the one thing I've noticed is that they all seem to have very low battery life. I just assumed many of these devices would get 6-10 hours of battery life when only reading e-books--don't laugh!

--but they all seem to be
much lower, more around the 2-3 hour mark from what I can tell.
Is there a color e-reader on the market priced under a $100 that
won't need a recharging after two hours of reading? I don't care about wifi, and I could care less about running apps and such. I just want to use it for reading the e-books I already own. Is this possible, or should I be looking at the black and white models like the Kobo? I really like the 7" color screens out there now, but if they're going to need a recharge so frequently I might have to reconsider the b&w models.
Thanks.