I have a MacBook Pro (Retina, Mid 2012) What seemed to be a one-off has happened more frequently and now occurs around once a week: Using computer unplugged, will shut off/sleep. If I hit the power button to turn it back on/wake it up it will either: Flash the low battery/plug-in adapter sign or Do nothing I plug in the adapter and it press the power button, it comes back to life. It always has plenty of battery life left, 25%, 37%, etc. once it comes back up. I have made sure to do all the updates (still on El Capitan, downloading Sierra as we speak) I have reset the SMC Energy saver is set to Automatic Graphics Switching, Computer Sleep @ 1.5 hrs, Display Sleep @ 1 hr, Put hard disks to sleep when possible, Slightly dim the display when on battery bower. This has happened during various activities, just surfing the web, viewing full-screen video, playing games, using iTunes... has happened on a countertop, a wooden table, and on my lap. No magnets/cases around either. Coconut Battery says that I am running 76.5% of design capacity, and have had 729 loadcycles It's a four year old computer, so no AppleCare or anything still on the computer, and I'm just wondering if there are any other things to test before I set up a Genius appointment.