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?

  • reset your System Management Controller (SMC) that controls the battery.
    – Ruskes
    Oct 18, 2018 at 8:04
  • @Buscar웃 I successfully reset the SMC controller yesterday, but this morning the same thing happened.
    – mdarwin
    Oct 19, 2018 at 8:05
  • Resetting SMC can be tricky to do and not always successful, to make sure you did it, watch the magsafe light, it should briefly change color. Also I need more details from you, like how long do you close the lid, how old is the battery, what is the cycle count on it.
    – Ruskes
    Oct 19, 2018 at 15:56
  • The SMC reset was successful. Lid is closed for 8 hours or so, battery age 4 years and cycle count around 700
    – mdarwin
    Oct 22, 2018 at 20:25
  • so did the SMC reset do the trick, or is the battery showing signs of aging, If you open About this Mack (top left) > System Report > Power..then copy the battery information and paste it in your original post, so I can help you understanding it.
    – Ruskes
    Oct 22, 2018 at 20:55

2 Answers 2


To verify your problem I need you to post the Battery status in detail.

Click About this Mack (top left) > Syst report > Power

then copy the battery information in your original post.

To preserve some power consumption, open syst pref > Energy and disable the Power nap in Battery mode.

To verify is some process is keeping your Mac awake (dark mode) and consuming power open Terminal and paste following

pmset g and post the info here

also run pmset -g assertions and post it here

Under normal (perfect) condition the battery should last 1,000 cycles, but that is not always the case, so your are getting close with your 700 cycles


The condition of the battery on my 2014 Macbook Pro is poor and it shuts down regularly when turned on if I'm not connected to power. However if I'm running Windows on Bootcamp I have no problems. Windows 10 carries on and tweaks it's own power settings at around 20%.

This suggests that the problem is software related.

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