So I got my Surface Pro last weekend. Loving it, but the obvious shortcoming is the battery life. Out of the box I get 4 hours give or take a half hour. (projected by the battery icon in the taskbar, I haven't sat down to record actual times)
But I've found this:
Start>right click computer>properties>advanced>click settings button in performance tab>visual effects tab>
click 'adjust for best performance' then check 'show window contents while dragging' (personal preference)
Also, creating a power plan, and then put display dim at 1 min, display turnoff at 1 min, and pc sleep at 3 minutes.
Also be sure to change everything in the advanced section to battery saving, and you can also goto the cpu power state section, and change cpu min to 0% and cpu max to 10%.
This isn't exactly correct from my testing as the cpu won't drop down past .78Ghz..... This might be a hardware requirement to run the W8 kernel? Until I get some answers from the wonder microshaft reps in the forum, it's all speculation... could be a bug..
Otherwise after the above adjustments, I have seen projections from the power icon from 6.5-8 hours.
I also don't notice the reduction of cpu max doing general things, the times I HAVE noticed a difference, it was a difference of a few seconds..
Oh, and if anyone else has any suggestions on a way to get better battery output please do post here...
I guess I forgot to include, I've been running with display brightness from 15-25%, at least for my saved more battery profile