i guess it all depends on the number of page turns..
pilotbob:
from the kindle website:
http://www.amazon.com/dp/B00154JDAI
under tech details it clearly states:
Battery Life: Read on a single charge for up to 4 days with wireless on. Turn wireless off and read for up to two weeks. Battery life will vary based on wireless usage, such as shopping the Kindle Store and downloading content. In low coverage areas or in 1xRTT only coverage, wireless usage will consume battery power more quickly.
(god i love that chin scratch guy)