I started with 4.5 hours and after the tweaks including the batter driver and some other settings I am now around 6-6.6 of regular browsing. I would really like to see about 8 hours. Perhaps an update will fix this. I disabled cortana but also notice it still runs in the task manager somewhat. I am hoping that some windows update tweaks in the future will grab us another hour or so at least like they did with the SP2 and SP3 about a month after they came out. I did alot of browser testing yesterday for an hour each and checked the battery drops. IE was the worst at about 20 percent an hour, Chrome was next at about 16 to 18 percent an hour, and Edge/Firefox were around 14-16 percent and the hideous Apple Safari was about 12-14 per hour. The browser definately makes some difference.