MacBook Pro M5 Pro: DarkWake causing overnight battery drain

<< I haven't [...] installed any weird programs... >>

except these:

com.crystalidea.macsfancontrol.smcwrite.plist (Ilya Parniuk - installed 2026-03-12)

    Executable: /Library/PrivilegedHelperTools/com.crystalidea.macsfancontrol.smcwrite

 Share services:

    [Loaded] Ulysses - /Applications/UlyssesMac.app

NotANewUser wrote:

I'm having the exact same issue with a brand new MacBook Air Apple M5.

I'm currently running macOS Tahoe 26.4.

My battery routinely drains 30-40% overnight, even with apps closed. I've had multiple Mac products (two Macbook Pro's, one Macbook Air) and never experienced this before.

The current stable release of Tahoe  including bug fixes,  security updates  is macOS 26.4.1 - I would start there

Keep your Mac up to date - Apple Support

Keep your Mac up to date - Apple Support

NotANewUser wrote:

I'm having the exact same issue with a brand new MacBook Air Apple M5. I'm currently running macOS Tahoe 26.4. My battery routinely drains 30-40% overnight, even with apps closed. I've had multiple Mac products (two Macbook Pro's, one Macbook Air) and never experienced this before.

I suggest you create a new thread for your specific issue so it gets the attention it deserves especially if you would like our assistance for trying to determine the source of the problem. While you may have the same symptoms as the OP, the root cause could be completely different.

Make sure to include a complete EtreCheck report so we can examine it for clues.

How to use the Add Text Feature When Posting an EtreCheck Report - Apple Community

As always, the simple solution is to connect the power adapter to the laptop overnight. Another option would be to completely power off the laptop. These new Macs boot so fast even from a cold boot, that this latter option is not much of a hindrance to keep the battery charged, especially if it cannot be connected to the power adapter.

pragyat17 wrote:

Also, they haven't been really able to pinpoint the issue, and they have been blaming it on external applications, Chrome, maybe even Logitech, and also on some bug. It's kind of weird that Apple has not been able to pinpoint this issue.

The only way I have been able to figure out what app/process is draining the battery is by using the information I provided earlier in this thread here:

@HWTech's post for identifying time period causing battery drain - Apple Community

This will help you identify the time period where the largest battery drain is occurring. Or this will show you a relatively small consistent percentage drop at each wake period which would indicate a regular & likely normal event based on your Mac's custom settings & installed third party apps.

The second step after gathering the sleep/wake events showing the battery charge levels (best to start with the wake period showing the largest battery drain)..... you will need to sift through 100Ks of junk entries in the logs for the period between wake & sleep to see if you can identify the actual app/process involved. This is not easy to do since 99% of the information is noise (aka junk) & meaningless. It is only for the most desperate since it can drive people crazy looking at the macOS system logs even for a period of one minute, much less 15+ minutes.

Probably the easiest method for the average user would be to "Erase All Content & Settings" followed by reinstalling third party apps one at a time until you see the drain begin again. Same goes for customizing macOS settings and signing into your AppleID/iCloud. This is the easiest & only way to learn what may be the source of the problem for you.....this is definitely a long slow approach.

I would recommend against restoring anything from a backup until your troubleshooting tests are complete, but if you insist on restoring from a Time Machine backup, then you must only transfer the home user account and its data making sure to unselect "Applications" and "Settings" (both within & without the home user folder accounts so you need to click the arrows to expand & show the additional options to restore within each user account), plus "System & Networking". Hold off on signing into the AppleID/iCloud until after testing to confirm no or minimal battery drain.

There is no easy quick way to figure things out. It takes a lot of work & experimentation to figure these things out.

The easiest & guaranteed method is for people to either keep the power adapter connected, or to fully power off the laptop. For some reason people seem to refuse the simple guaranteed methods. To each their own.

Follow the excellent advice of Grant Bennet-Alder above. Plug in your computer whenever near a power source. If you will be away from power for some period of time, shut down the computer rather than just put it to sleep.

There is no need to uninstall Ulysses if it is something you want to use. Just be aware that it, along with other network-aware apps on your Mac, will be active over the network even while your Mac appears to be "sleeping" all night, so all you need to do is connect the charger at night. It's not a bug and I don't think anything is wrong with your Mac hardware. It's just that you have various software that "phones home," as designed and intended.

(If you replace your Mac with another one, it will do the same thing after you reproduce the setup you have on this one.)

Just connect the charger when leaving the Mac overnight.

You might not have seen this background activity when using the Mac, as you mentioned, because some of these softwares wait to perform this network activity until the Mac appears to be idle.

xpl0it wrote:

Yeah this is happening with me as well occasionally.

M5 MacBook Air.

And yes I checked the DarkWake entries. Most of them were network activity.

Hoping for a solution.

That will usually be associated with cloud file syncing services or possibly third party apps checking/performing updates, etc.

I know that iCloud will do a lot of file syncing overnight if a lot of changes were made during the day.

If you can plug in the laptop, then do so since it won't run down your battery, otherwise complete Shutdown the laptop overnight. The only other option is to reconfigure your settings to eliminate some of the online capabilities so that there is no more network activity overnight......of course that will likely impact some of those features you rely on. So the first two options seem to be the best options.

flash608 wrote:

Hi, please test your Mac with Wi-Fi and BT turned off manualy before you close the lid/put it into to sleep mode and see if you'll have any darkwakes after that. I'll bet it will sleep like a baby :)

Having read all the Gemini scripts and other acrobatics people are doing here, it's pretty clear that things have been installed that "call home" or otherwise connect, even while "asleep." and for different users, different items installed can cause this.

Isn't it easier just to connect the charger to the Mac when the lid is closed for the night (as recommended by Apple)? Then you don't need to switch this and that off and on every day, run scripts, kill processes, whatnot, and you can configure your Mac the way you want.

pragyat17 wrote:

I came back and didn't add my logitech mouse (as some people believed that the Logitech mouse caused this). My battery still drained (going from 32% at 3:30am to 14% to 1pm) which is an odd behavior. I will keep the community posted on what's happening here.

It would be of interest if you did the test on a machine that had been completely wiped and reset with nothing installed. Or, what did you bring back before you did this test? Did you migrate back your account and anything else?

My daughter frequently leaves her new MacBook Pro overnight with the lid closed and no charger connected (although I have advised her not to do that). When I let checked, her laptop lost only a few percent of charge sleeping like that overnight.

terriermind wrote:

Ulysses is a well known writing app that is recommended by the apple community and is not a dangerous app to install.

Ulysses for Mac web site has this:

Work Anywhere, Anytime

All your texts will be stored in Ulysses’ library, and seamlessly sync to all your connected devices. It doesn’t matter where you are or when inspiration hits: All of Ulysses’ tools, and all your texts, are always at your fingertips.

I don't own nor use Ulysses but from the above, it sounds like there is ongoing network activity and interaction with libraries over the internet. Perhaps this can be configured (or turned off) in the app's settings, I don't know. But it is consistent with regular network activity that uses energy (Battery) and that I believe you squelched when you disabled your Mac's WiFi in your experiment. Something like this can easily use up 25% or more of a battery overnight. Why on Earth don't you just plug it in overnight and resolve the issue?

I also noticed you have iCloud, that may also involve more over the air communications through the night.

Also ...

Top Processes Snapshot by Network Use:

Process (count) Input / Output (Source - Location)

...

exchangesyncd

rapportd

This exchangesyncd is some sort of syncing, it is using the network, that too will take energy (battery). And rapportd is an Apple system daemon (/usr/libexec/rapportd) in macOS that enables communication between Apple devices. It supports Continuity features like Phone Call Handoff, AirPlay 2, and Instant Hotspot, allowing secure connections between nearby devices.

These things are no doubt running in the background, including all night, using up your battery. When you turned off WiFi you probably disabled them and your battery usage went down.

Again, as suggested by others ... simply plug in the Mac when it won't be used for a while (overnight ... one week ...).

I'm having a similar experience. I have an M5 that's almost the same build as yours. While in sleep mode I experienced about a 20% loss in roughly 24 hours. I brought the laptop to Apple yesterday and they performed a diagnostic test on the battery and said everything looked normal. They said I could just swap it out because I'm within the 14 day window. I really don't think that's the proper solution. Have you gotten any new insight on this?

Just curious, I have been facing this exact same issue.

Could this be because of using a logitech wireless mouse? I currently use the Logitech LIFT and have heard the logitech mouse can cause these issues. Has someone here faced this issue without owning / using a Logitech mouse?