htc mogul battery, help me !!!

[rbags]

my htc mogul battery/charger has been killing me. it will claim to be fully charged. after about any hour of little use, the battery dies and says 0%. I plug it in the charger, car or wall, and it says "state: charging..." however i could leave it on the charger for 2 hrs and it will still say "charging..." but remain at 0%. then randomly it will jump to 100% and the whole process will repeat: maybe 1 hr. of use, die, charge, etc... I took the battery to get tested and they said it is good. I have done several hard resets thinking there might be something I can't find that is draining the battery. so far that hasn't helped. any suggestions. I'll take anything. I'm about to lose it.