Yesterday we started using it on battery at noon. Sat and used Word for a few hours, a little browsing. Each time I got up to do something, I'd put it to sleep. Worked more, put it asleep during dinner. Then went back to work. When I stopped at 11:30 PM the battery was down to 3%. I didn't keep track exactly of hours of use, but I swear I'm getting at least 8 hours of use on a full charge. Simply amazing.