Why is My Mac Draining Battery While Sleeping?
Some MacBook Pro, MacBook Air, and MacBook users may have noticed their computers are draining battery even when the Mac is sleeping and not in use. This seems like a peculiar issue, but it turns out there there may be an explanation.
A simple way to diagnose this issue is by going to Apple menu > System Preferences > Battery, then choosing “Usage History”. When you see the battery level drop but the ‘Screen On Usage’ is nonexistent, you know the battery is draining when the Mac is not in use. The screenshot above demonstrates this in a severe case, where a MacBook Air drained the entire battery when not in use.
Fixing MacBook Pro Battery Draining When Sleeping
Usually this happens because the Mac is not actually sleeping, the screen is just off, or the Mac is being woken up. Or, a feature called Power Nap is turned on the Mac laptop. Let’s look into this with a variety of troubleshooting tricks.
Find Apps/Processes Preventing Sleep
Some apps and command line tools specifically prevent sleep, so determining which and why is important. You can use the command line and pmset to figure this out, or Activity Monitor, which easier for most users.
- Open Activity Monitor from Spotlight by hitting Command+Spacebar then typing ‘Activity Monitor’ and hitting return
- Pull down the “View” menu and go to “Columns” and check the “Preventing Sleep” column on
- Now you can sort by “Preventing Sleep” to see what, if any, processes or apps are preventing the Mac from sleeping
If you a specific application is preventing sleep, simply quitting the app usually resolves the problem.
For example, sometimes the OpenEmu emulator will prevent sleep on a Mac, so if that app is open and running you may not be able to actually put the Mac to sleep, as you see in the screenshot above.
Command line processes like caffeinate are designed to prevent sleep so if you see something like that running, that’s certainly the cause.
Disabling Power Nap
Some MacBook Pro and MacBook Air laptops support a feature called Power Nap, which allows the Mac to check email and get notifications while it should be asleep. Turning this off may resolve some battery draining while sleeping issues, particularly if you get a lot of emails and notifications.
- From Apple menu go to “System Preferences” and choose “Battery”
- In the Battery tab, uncheck the box for “Enable Power Nap when on battery”
Disabling Enhanced Notifications
Some Macs also use a feature called Enhanced Notifications to deliver notifications when the display is sleeping, you can turn those off which may ameliorate battery draining when the Mac should be sleeping as well.
Advanced: Finding out exactly why the Mac waking from sleep
If you’re more technically inclined and comfortable with the command line, you can follow this guide to see exactly why a Mac is waking from sleep. Often you’ll see things like AirPort (wi-fi) activity, lid opening, or keyboard/mouse activity shown, but because it’s using system logs to determine this it is not particularly in a user friendly format.
There are a few helpful commands to refer to that may lead you to discover the reason, process, or app that is causing the Mac to wake from sleep. You can refer to these as needed, and it may be helpful to run each command separately to investigate the Macbook battery draining issue.
Run these commands from the Terminal application.
Using log to discover wake requests on MacBook laptop:
log show | grep -i "Wake Request"
This may reveal something like the following, where ‘powerd’ is waking the Mac with an “RTC” request which is often an automated behavior, whether it’s waking on schedule or on network request:
2021-11-03 22:02:38.472928-0700 0x5cb1b Default 0x0 76 0 powerd: [powerd:wakeRequests] Selected RTC wake request:
Using pmset to find wake requests on Mac laptops:
pmset -g log |grep "Wake Request"
May return something like, where the ‘process’ is the reason for the wake request:
2021-11-30 13:33:36 -0800 Wake Requests [*process=SuperUpdaterPro request=Maintenance deltaSecs=7200 wakeAt=2021-11-30 15:33:36 info="upkeep wake"] [process=powerd request=TCPKATurnOff deltaSecs=99481 wakeAt=2021-12-01 17:11:38]
Using log again to discover wake reasons for MacBook laptops
log show |grep -i "Wake reason"
May return something like, where ‘AppleTopCaseHIDEventDriver’ indicates the lid of the Mac laptop was opened:
2021-10-26 00:48:13.953155-0700 0x12174 Default 0x0 0 0 kernel: (AppleTopCaseHIDEventDriver) [HID] [ATC] [Error] AppleDeviceManagementHIDEventService::setWakeReason Error setting wake reason (reportID = 0xc5, Return Value = 0xe0005000)
Rebooting, resetting SMC, disconnecting peripherals and USB devices, and miscellania
Sometimes users can stop mysterious inability to sleep or power draining issues by simply rebooting the Mac.
Also, disconnecting peripherals like USB devices or other gadgets may resolve the issue.
Another common troubleshooting trick for mystery power issues is to reset the SMC on the Mac (this only applies to Intel Macs, as Apple Silicon does not have SMC), which can often resolve issues if a Mac won’t sleep.
It can also be generally useful to how long your MacBook battery actually lasts for, which you can check in Activity Monitor as well.
Have you experienced any issues with your MacBook Pro, MacBook Air, or MacBook draining battery while the computer is sleeping, or otherwise not in use? Did you find a solution? Did the tips mentioned here help? Share with us your own experiences in the comments.