HTC EVO 4G
Is 4 hours the longest you're getting out of your battery???
I've seen it in my store, I see it in reviews here. Task killers and closing apps isn't going to help you. Proper setting will. I can get 6-8 hours of HEAVY usage out of my phone, 16-20 hours straight of moderate usage. It's still not phenomenal but far better than what some are experiencing. Here's how to fix your problem.
From the home screen, menu>settings>Wireless & Networks>4G settings, Uncheck the 4G box, Uncheck notify me when a 4g network is available.
Thank me later.