Taking in all the factors - usage/screen etc etc how an earth are you managing to get 8-8.5 hours of battery life! please do share your tips/setup. Also does this include any video/movie viewing.
Nothing special really. On battery, the screen brightness is 39% (45% when on mains), I don't watch any movies/ video on it when on battery. Most commonly, I am working in Word with OneDrive open, MUI IE with one or two tabs open, Mail app open polling three accounts (two Outlook accounts and my work account - mails to be received and displayed as they come in and notifications on), Drawboard PDF open usually with 2 documents. In addition to this, I have Flipboard, Tweetium, Calendar, Next Gen Reader, Skype, Redditt2Go, the MS Store, Viber and Photos set to show notifications. I assume, therefore, that they are also running in the background. BT and Wifi are always on. Camera is off. That's about it really. On some other battery-related threads here, I have posted some recent battery reports, which also show the 8-8hr 30 min timeframe.
Having said that, I found that after the most recent firmware update, I was getting around 6 hrs to 6 hr 30 mins. This was irritating me enough to have posted a query on one of the threads here. Someone noted that they had reset their device and they had experienced improved battery life. So, I did the same - though I did not reset (don't have that much patience). Rather, I refreshed the device (which was also a pain, but a lesser pain). And, I noticed better battery life immediately (after all the indexing etc. and update-installations etc. were done).