When you say normal work, what would that entail? What types are you surfing, static information or Flash Based Games or Content? Are Videos Flash or HTML 5 rendered. I honestly get 9-12 hours of normal work (if I use my Surface 2 for many Conference Calls I lose around 2-3 hours of battery life). I mostly consume information via reading and spend way too much time on Tablet Forums.
What I do:
Surfing most of the time with 2-3 open Browsers. Most pages are just Content like that one here and some have Videos as well (e.g. nba.com, spox.com).
I also use Word, PowerPoint etc. and I´m switching between using the Internet and documents a lot.
Also Facebook, Outlook is used a lot with Outlook ready to load new E-Mail any time.
I think with that rather conservative using I should get out more than I do at the moment.
As I said, I made the video-Loop test and had to stop it after 9hrs because I needed my Surface but it had power for at least 3-4 more hours. So that was a pretty good result. Don´t know what´s going on with the battery when I normally use my S2.