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vett93

macrumors 6502
Original poster
Jul 27, 2014
279
40
California
I have a new M1 MBP with 16GB RAM and 512GB SSD. It sleeps fine when nothing is attached to it. But if I attach an external monitor via the Apple USB-C to HDMI/USB-A connector, it would drain the battery completely while sleep in about 24-30 hours.

This M1 MBP runs 11.4 OS. I searched the net and it seems to be a common problem. I can't find a solution for it. Anyone knows?
 

vett93

macrumors 6502
Original poster
Jul 27, 2014
279
40
California
Why are you leaving your Mac on battery while connected to an external monitor?
Do you disconnect everything from your laptop when you are done working for the day? I certainly don't. I just put the MBP to sleep mode and turn off the power to the external monitor and Mac's power adapter, when I am done working for the day. Then I turn on the power the next morning and wake up the MBP to continue my work.
 
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Apple_Robert

Contributor
Sep 21, 2012
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In the middle of several books.
Do you disconnect everything from your laptop when you are done working for the day? I certainly don't. I just put the MBP to sleep mode and turn off the power to the external monitor and Mac's power adapter, when I am done working for the day. Then I turn on the power the next morning and wake up the MBP to continue my work.
I leave everything plugged in and running.

I have read of a few reports on the forum about losing battery while in sleep mode. I don't recall if it was also with an external monitor attached.
 

vett93

macrumors 6502
Original poster
Jul 27, 2014
279
40
California
There have been reports with both cases. I still have not seen a solution to the sleep problem with external monitor attached.
 

jdb8167

macrumors 601
Nov 17, 2008
4,780
4,504
I have a new M1 MBP with 16GB RAM and 512GB SSD. It sleeps fine when nothing is attached to it. But if I attach an external monitor via the Apple USB-C to HDMI/USB-A connector, it would drain the battery completely while sleep in about 24-30 hours.

This M1 MBP runs 11.4 OS. I searched the net and it seems to be a common problem. I can't find a solution for it. Anyone knows?
You can experiment with pmset to see if you can fix the problem. MacOS automatically puts your computer to sleep if it is in clamshell mode on battery but attached to an external display. You might have a conflict between this sleep mode, and PowerNap. To turn this mode off: sudo pmset disablesleep 1. Set it back to 0 when done experimenting. You might have to put your computer to sleep using the menu using this mode.
 

vett93

macrumors 6502
Original poster
Jul 27, 2014
279
40
California
I had tried 'pmset' in the past for other issues. I don't understand why you wanted to disable sleep though. I have tried a few other power settings but none of them helped. So I contacted Apple Support.

I have talked to 3 advisors, 2 sr. advisors, and 1 Level 3 support in the last few days. The first advisor said it was normal behavior and nothing to worry. (haha) Then my M1 Mac went through the regular SMC reset, NVRAM reset, new user, and safe mode through these advisors and sr. advisors. None of them helped.

They sent me to a Level 3 support today and the guy said others had similar problems too. The guy filed a ticket to their engineering team. I told the Level 3 support person that I had seen this issue raised in internet forum since Nov 2020. He told me that he had seen the same post as well.

I usually use my main computer, an almost 8 year old trashcan Mac Pro, for work items. IMO, the M1 Mac is over rated.
 

lcubed

macrumors 6502a
Nov 19, 2020
540
325
why are you turning off the power to the laptop power adapter
and the monitor?

i just put mine to sleep and walk away.
 
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vett93

macrumors 6502
Original poster
Jul 27, 2014
279
40
California
why are you turning off the power to the laptop power adapter
and the monitor?

i just put mine to sleep and walk away.
Mainly for cooling and energy conserving reasons. I have a MP, a M1 MBP, and a HP Elite laptop in my home office, along with 43", 32", 27", and 24" monitors. The room would heat up quickly if I keep them on.
 

xraydoc

Contributor
Oct 9, 2005
10,856
5,329
192.168.1.1
To me it sounds like something about the monitor and/or adapter is making the Mac think a display is connected and still powered on, thus the computer not staying in sleep mode.

I had a situation with my old laptop, a Microsoft SurfaceBook 2 with the Surface Dock, where my LG monitor connected via DisplayPort would go into low power mode, then immediately back on when the laptop was either asleep or powered off. The monitor would cycle between low-power sleep and back on, then see there's no signal and go into low-power mode, only to come right back on again. If I removed the Dock from the setup or connected the monitor via USB-C instead of DisplayPort, it would properly stay in low-power sleep mode. So something weird about the dock was causing it. I had to power the monitor OFF to stop it from cycling. It was a bit of a hassle because I need to turn it back on manually each time instead of allowing it to wake from low-power mode automatically. BUT there were no such problems with a different Dell monitor. So go figure.

Basically what I'm saying is that it may not entirely be the fault of the MacBook in this case, but a weird combo between the MacBook, that particular monitor, and that adapter.

Try changing around how it's connected and see if it persists (different USB-C adapter, different connector type - HDMI vs. DisplayPort vs. native USB-C if available, etc).
 

macsound1

macrumors 6502a
May 17, 2007
829
857
SF Bay Area
Does the same thing happen if you unplug the power cable from the mac instead of turning off what I'm assuming is a power strip?
What could be an issue is that whatever you're using to "turn off" the power to the laptop's power adapter is still allowing some electricity to flow through. So once the capacitors get energized in the transformer, it charges for a second, then stops. This could be happening once a minute and waking up the computer.
 

vett93

macrumors 6502
Original poster
Jul 27, 2014
279
40
California
There is no dock involved in this setup. The Dell monitor is connected to the M1 MBP via an Apple USB-C to HDMI connector. If I swap out this M1 Mac with my 2019 13" MBP, there is no problem

Interestingly, the M1 Mac appears to be sleeping on the Power History graph in the System Preferences. It would show that the M1 Mac is charged to 100% the night before. Then no power recording for 10 hours. Then it shows 50% power when it woke up.

I also tried an OWC TB3 dock in place of the Apple USB-C to HDMI adapter. There is no battery drain in this configuration.
 

vett93

macrumors 6502
Original poster
Jul 27, 2014
279
40
California
Does the same thing happen if you unplug the power cable from the mac instead of turning off what I'm assuming is a power strip?
What could be an issue is that whatever you're using to "turn off" the power to the laptop's power adapter is still allowing some electricity to flow through. So once the capacitors get energized in the transformer, it charges for a second, then stops. This could be happening once a minute and waking up the computer.
The power strip has a few other devices as well. These devices do get turn off when I switch off the power strip. Additionally, the battery icon on the M1 MBP would show no charging either.
 

Navvier

macrumors member
Aug 4, 2018
67
24
The same issue here.
I'm facing a 50% discharge after 12 hours of MBP sleeping with only monitor attached (via USB-C -> HDMI adapter)

MBP 2020 Intel 10th gen
 

vett93

macrumors 6502
Original poster
Jul 27, 2014
279
40
California
I finally gave up and used the powered OWC docking station between the MBP and monitor. I power off the OWC docking station and the power drain stops.
 

Chancha

macrumors 68020
Mar 19, 2014
2,140
1,931
I had a similar issue with an OWC/Akitio Pro Dock attaching to a 16", however my problem with it is not battery drain but with heat, the 16" despite lid closed would have heat build up even when it clearly slept overnight. There is an external monitor attached via the dock's DP port, during normal usage the MBP as we know gets hot easily which I am fine with, but it is puzzling to find it not cooling down when sleep.

My solution is to unplug the dock altogether and let the MBP sleep with nothing attached, may not be what some of you want to do but I couldn't carry myself to troubleshoot further.
 

WilsH

macrumors newbie
Nov 13, 2021
1
1
I'm running an M1 MBA and using a cheap USB-C dongle to connect via HDMI to a DELL external monitor. When I put the MBA to sleep overnight leaving the dongle plugged in the battery drains approximately 50% but if I disconnect the dongle then the battery does not drain at all overnight. The dongle also connects to a powered USB hub, but I power that off. I do not leave any applications open (such as Chrome, Mail, etc.). Think I'll try disconnecting the USB hub next to see whether it's the hub, the monitor or both that is causing the issue.
 
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Le0M

macrumors 6502a
Aug 13, 2020
882
1,223
2023, on my MBP M1 I'm still having this issue, and I'm using a dongle for an external mouse only.
I mean, how is it possible that it drains battery? It's a damn mouse, with an led light in it, and that's it!
It's so frustrating, and Apple hasn't fixed it yet.
 
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