Hello. I have a brand new MacBook ( < 1 month old ). I usually leave it plugged in and sleeping on my desk, and open it up to use it. After about a day of this, it will still say the battery is fully charged, and the light on the MagSafe is green, but the batter display shows 99% (or 98%, 97%, 96%). If I unplug it and use it for a bit, and the plug it in again, the battery will charge back up to 100% (and then the whole process will begin again). I love my MacBook, and want to make sure this behavior is normal. Thanks!