What is your signal strength? If it's less than 4 bars, I've found it does drain battery. Also, do you have 4G enabled? Even worse battery drain especially if not at full signal strength.
The low signal strength drain is the biggest problem Sprint has, I think. I've had this problem on every Sprint phone. I wish someone would make the "use all available power to search for better signal" algorithm a bit less aggressive. In fact, if I have poor signal AND am doing data over 3G, the phone gets hot! Turn on WiFi if you do this (if you can). That's been my solution for years.
I get 16+ hours on my phone, now, with push mail on four accounts, 15-minute updates on other accounts (twitter, some email, etc.) <10 minutes of voice, a few texts and 1+ hours of web use (not downloading that whole time, of course). At this point, I'm a bit under 30% charge, on average... extrapolating (which is not quite valid, but whatever...) that's 22 hours. I'm not playing online games or watching movies, but I do watch a youtube video occasionally, for example. I'm not trying to save battery, but using the device as I think I should.
Finally, here are some screen shots clearly showing what others have said (including me but now I have photos):
1) Notice what happens as you get to 100% charge:
2) Here's my last three days of usage to "prove" what I'm saying, above:
My battery lfe is very good
