Either I was unclear in what I wrote, or you misunderstood - it is probably the former than the latter. Let me explain. When I run the battery report, the HTML file that it throws out says that I get 8.30 mins of battery life since the day I bought the SP3 (June 20th). However, I use the SP3 on an average of 10-11 hours on a typical work day. But my typical work day does not involve the use of the machine continuously. It does mean that my SP 3 is both working and when not actively being used is always on Connected Standby (or whatever it is called) for 10-11 hours a day. Also, I never shut down the device. When on Connected Standby, the machine is polling three email accounts of which two are Outlook accounts (one set to poll continuously and the other every 15 minutes) and the other is my work mail account (set to poll every 15 minutes). The brightness level is at 38%. I have 12 notifications on including Mail, Calendar, Flipboard, News, among others. Since I work in academia, I am usually using Word and Powerpoint. Occasionally, I use Excel. On the MUI side, I use IE, OneNote (I use the Pen extensively), Mail, Calendar, Weather and Contacts (IE usually has 3 tabs open), Book Viser, among others). I am careful to close apps (waiting for the Live Tile to flip) if I don't use it. BT and WIFI are on all the time.
Based on this usage, at the end of the day I end up with around 35% of the battery left. My personal estimate is that I probably use the device for around 6-7 hours per day of continuous use.