I just purchased a 15" mid-2012 MBPr. It's been working wonderfully so far, but I'm concerned about the battery. I've had it for 3 days and when it's "charged," it is listed at 99% battery. This morning, after charging it/letting it sleep all night, the "charged" battery is listed at 97%. Should I be concerned, and if so, what can I do? I'd hate to have to take it in for a battery replacement so soon after I got it. I'm letting it run off the battery for now to see if I can recalibrate it. But I'm a bit paranoid, especially since I just got the computer.