I bought my MBP 15 in August of this year. For the first month or so I was charging the battery and then unplugging when full. I then decided to just leave it plugged in all the time. I've been running coconut Battery since the beginning. Until I began leaving it plugged in all the time, the current capacity was increasing above the 6900 mAh design capacity. For two weeks I left it plugged in, and now my current capacity is at a meager 6759 mAh or 97%. Age of Mac 15 weeks. Battery load cycles 31. At this point it doesn't seem to make much sense to worry about the capacity and to just leave it plugged in. I've calibrated the battery since and it doesn't increase the current capacity.