[citation][nom]GiveMeADay[/nom]As a HTC Vivid owner, I couldn't disagree with HTC more! My stupid phone doesn't even last a day. I am actually looking at a replacement battery now, but I have to sacrifice a modified back. That's OK with me! Just give me a solid day of use![/citation]
It is possible that you could extend your battery life dramatically. When I got my phone, the battery lasted 4 hours. When I got done updating, it lasted 8ish hours. After installing Juice Defender and Watch Dog, the battery lasted a full day unless heavily used. After installing LTE OnOff, my batter lasts 2 days (This utility required rooting).
Better batters are one way to improve things, but software and utility changes can dramatically help you as well. If you like your phone, other than the battery life, you might want to look around for help.