Originally Posted by The Solutor
You must get used with the battery indication curve.
Like on most phones the curve is not exactly linear. Most of the power is drained between 45 and 100%, so when you read 35% likely you have something like a real 15%.
Just use "battery monitor widget" for a week or so to realize what's going on.
I have widget that shows me battery usage. It calls "quick battery"