I'm trying to figure out my battery too, as i think it's draining quicker than it should. When i went to sleep at 1 am last night it was on 72% and this morning, at 7am, it was on 24% (it seems to be losing 4% every 30 minutes). I have Juicedefender enabled to data connect every 3 minutes. Background sync is on. Other than that the phone is on idle. This morning when i woke up, wi-fi was connected for some reason, and according to Juiceplotter, it had been connected for 30 mins.
Seems to me, 8% per hour is way too much, according to some of the above posts in this thread.
Another question: i used to charge my phone overnight, but since my phone is set to silent, i don't know when it's fully charged. I wonder if that killed the battery somehow, since i left it on 100% charge for a few hours?