I have a new MBP (replacement). Sometimes I have been closing my computer, setting it in sleep mode, only to find when I arrive at school that the battery is totally dead. Just 5 minutes ago I had 3+ hours on my battery. I closed it for a couple of minutes. I now have 14 minutes left. This occurred without any physical movement of the laptop, with the exception of closing the screen to activate sleep mode. Anyone have any suggestions? PS. When I first got this machine, I wasted down the battery, then fully charged it before use.