My retina MacBook Pro, running 10.12.6, has an annoying habit.
If I close the lid on 50% battery, the next time I open it, it wakes, I log in, and then a few seconds later the screen goes black and it shuts down.
Pressing the power button enough brings up the 'flat battery' logo.
My assumption was that the battery is reporting 50%, but is in fact flat.
If I plug it in to charge, it then resumes where it left off, but if I unplug the power, it will continue to work for another couple of hours. So it's not actually drained, it just temporarily thinks it is.
What can I do, other than replace the battery?