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macOS Mojave 10.14 Sleep

Introduction

I purchased my shiny new 2018 MacBook Pro, my first Mac, in February 2019. After getting familiar with it, I noticed I was not at all impressed with the battery consumption while sleeping. After just a few hours sleeping with the lid closed, I noticed a significant portion of the battery capacity was gone. That really defeats the entire purpose of sleep mode. After a bunch of searching, I discovered two surprising things that are terrible for battery life:

The constant cycle of auto wake, performing some action, writing RAM to disk, and going back to sleep just eats battery. I also discovered that not all power-related settings are exposed in System Preferences. So I set out to try to fix things and I came across a few articles discussing the pmset command-line utility.

macOS Mojave 10.14



DarkWake

In the "pmset -g log", automatic waking without user interaction is called DarkWake. You can see events related to this discussion with "pmset -g log | grep -i 'sleep\|wake'". This shot shows the periodic and frequent wake/sleep cycle just to check for updates. My mission is to eliminate DarkWake events.



System Preferences Changes



pmset Changes

These settings, set with "pmset -b" and "pmset -a", along with the System Preferences seemed to do the trick.


A couple more tweaks set hibernatemode, standby, and autopoweroff to 0, which prevents RAM from being written to disk during sleep. This may not be the desired behavior for everyone, but that is what I want for my sleep/wake behavior and minimal battery consumption.