Try the Rezound Standard Battery
http://www.amazon.com/HTC-Rezound-ADR6425-Standard-BTR6425B/dp/B0079Q67IC
The price of this battery is less than $10 on Amazon and it has done amazing things for me. I had the same crummy 6 hour life until I put this one in my Bolt. WOW what a difference! Usually lasts all day unless I am really using it heavily.