I'm sure someone has made a post about this but i think it would be easier and better to have its own thread that people can look at.
So to obtain a full charge and make your battery last longer follow these steps:
1. Plug in the charger and charge until the light turns green.
2. Unplug the charger
3. Turn off the phone
4. Plug the charger back in (red light will turn on again) and charge until its green.
5. Unplug the charger
6. Wait 5 minutes (with phone still off)
7. Plug the charger back in (red light will turn on once again) and charge until its green again.
8. You are ready to go with a FULL battery and can now turn on your phone.
Hopefully this method is only temporary, this should be something HTC looks into fixing very fast!