Well for me, it was at first 6 hours of light use and I felt a bit scammed. After prolonged uses (like 1 month or so), the battery became extremely better. I start school from 7pm - 3pm, and always have wi-fi connected. Generally in those hours I browse, type, take pictures of teacher's notes, download media and watch youtube. It lasted the whole school day (9 hours), and after coming home I still had 15% battery to fiddle around with more browsing and streaming for about an hour. So in total it was about 10 hours of moderate use. Be warned though when you first purchase the Surface 2, use it for a prolonged time for the battery to be able to live a long time.