I've recently run into an unusual problem. my MBP is powering down, without warning at around the 45% charge region. It quite simply gives up, doesn't tell me i'm running out of power, shuts down and refuses to boot unless it's plugged in. My question therefore is, is my battery completely screwed? Why does OS X think it's 45% full when there's blatantly f*all charge remaining and, will applecare cover a replacement? i've got 2 years remaining..