I have an HTC Evo. It got to the point where it would only go 10 minutes on a charge. I got a new battery and that helped for a couple of weeks and then it went back to the same nonsense. Sometimes I guess phones just get old.
Your “new” battery was likely an old new battery that had been on the shelf discharged too long.
The original HTC Evo just had horrible battery life. I have the new 4G LTE model and it’s battery lasts what seems like forever.