I have a mid-2012(non-Retina) 15" Macbook Pro that I have been having a strange problem with the last few days. I'm running 10.9.5 as the primary OS(although I have El Capitan installed on a secondary partition). In any case, when I'm finished with it in the evening I generally put it to sleep just by closing the lid. The computer stays plugged in all night. When I access it the next morning, it will seemingly wake from a "deep sleep" as if the battery had run down. I will get a grayed out screen along with a progress bar showing the "wake" process. I bought the computer used, but it had the battery replaced under Applecare right before I bought it(i.e. it showed 1 cycle the first time I started it). It's currently at 37 cycles, and gets what I'd consider "healthy" charge/discharge cycles(i.e. down to 40-50% at some point most days, and an occasional discharge down to 10-20%). This seems to only happen overnight when plugged in. The computer goes to work with me every day, but usually is put away and unplugged-it's sometimes 8-9 hours before I access it again, and it will wake right up as normal. Similarly, I don't have a problem with the computer plugged in or unplugged when it's put to sleep for a few minutes or a few hours. Any ideas about what could be going on?