This is the first time my phone has done this after about 2 months of owning it. I took it off the charger this morning at 100%. The Android OS has been running fairly high for a couple weeks, but not the 53% it's at today. The phone felt a little warmer than usual and is sucking battery life like it's going out of style. I'm even in 3G and have barely used the phone at all today yet it's down to 43% in under 7 hours.