| | Re: VERY unusual battery drain.....what happened?
If you have let the battery rundown past 20% on a somewhat regular basis, more than a few times, then you might have damaged the battery. lithium batteries do not like to get down past 20%. Keeping them topped up seems to make them work better and last longer.
So my guess is that it is a battery problem, unless you had open apps that kept hitting the web, such as Facebook and Twitter.