Ive seen this problem on other forums mentioned from almost year ago (on other HTC phones) to as recently as a few weeks ago with no fixes. Rather than join a half dozen new forums i figured i will post here.
using the wall charger that came with my phone, i plug my thunderbolt in overnight while the phone is on and the orange charge indicator comes on as it should. in the morning, the green charge complete light is on and the battery icon shows it is full and no longer charging.
now the problem is, once i unplug it, the battery icon drops either instantly or within a minute, sometimes its about 3/4, sometimes half, and on a few instances it went straight to yellow, and on one instance the battery was completely dead, wouldnt turn on at all, even while still plugged in and green light on.i suspect this might have something to do with the random sut downs i was expreiencing back in may, and even after the update early this july.
I have noticed that even once the green charge complete light comes on, i can immediately plug it back in and the orange charging light will come on for anywhere from 15 minutes to an hour. then the green charge complete light comes back on, and once again i can unplug it, plug it back in and it will accept a charge a few more times for another 15 minutes or so without me using the phone.
i dont see what ungodly comnination of apps running in the background would cause the phone to lose 15 minutes worth of charging time during the few seconds it is off the charger. i have read that the phone supposedly stops charging the battery once it is full. but why would it give up when there is still another hour or two of battery space to be charged?