I have a MacBook Pro (Retina, 13-inch, Late 2012) running OS X Yosemite 10.10.1 I'm frequently experiencing a weird behaviour in battery charging and discharging problem. All suddenly it goes from %50~60ish to %100 while connected to the charger, and while disconnected from charger goes from 100 to 50~60 at once. It's not something for all the time, but it happens frequently and each time of the same behaviour. I bring it to Apple store and they ran all tests on it, and told everything is OK with battery and charger, but I'm experiencing the same issue yet and unfortunately I have received no reasonable response from Apple technicians/engineers/genius-bar . I have uploaded complete screenshots and some discussion here: https://discussions.apple.com/thread/6791519 Is anybody else experiencing something like this? Is there anyway to ask for a replacement? Any suggestion is highly appreciated.