I've been trying to troubleshoot this problem on my friends Macbook, but I am not sure what to do next. Basically even on a full charge the Macbook won't even boot up. Sometimes you'll hear the boot chime, but it will just turn off. I ran Coconut battery and it shows the current battery capacity at 4885 or 97%. It has 699 battery load cycles and is 28 months old. I realize this is pretty old, but this problem just started happening. First thing I did was reset the SMC (turn off, disconnect AC, pull battery out, hold power button for 5 seconds, put battery back in, turn on). I tried this a couple times and it did nothing. I can't calibrate the battery since the system just dies when it doesn't have AC power, so the battery is fully charged right now. The system has Applecare, so I am wondering if they will just replace the battery. One thing I haven't tried is resetting the PRAM, although I don't think that has anything to do with the battery correct?