Besides the processor, battery life is dependent on other hardware options in the computer. In regard to the i7, I've seen reports of battery life from a little over an hour to 3 hours, so it varies. I would assume that the i3 is along the same lines, i.e. same technology, but may potentially last longer. You might as well snag the laptop with the i7 and gt240, as that isn't a bad deal at all.