MacBook Air 2012 with Sierra 10.12.6

Something is draining my battery overnight.

The pmset -g assertions Assertion status system-wide:

BackgroundTask                 0
   ApplePushServiceTask           0
   UserIsActive                   1
   PreventUserIdleDisplaySleep    0
   PreventSystemSleep             0
   ExternalMedia                  0
   PreventUserIdleSystemSleep     0
   NetworkClientActive            0
Listed by owning process:
   pid 117(hidd): [0x00052d7300099bbd] 02:56:54 UserIsActive named: "com.apple.iohideventsystem.queue.tickle.4294976712.3" 
    Timeout will fire in 1440 secs Action=TimeoutActionRelease
No kernel assertions.
Idle sleep preventers: IODisplayWrangler

Turned off WiFi and anything that would wake it up or keep awake, problem remains. Battery is down to 5-10% in 8 hours of sleep time. Battery is new (6 months old)

Charge Information:
  Charge Remaining (mAh):   7334
  Fully Charged:    Yes
  Charging: No
  Full Charge Capacity (mAh):   7340
  Health Information:
  Cycle Count:  15
  Condition:    Normal
  Battery Installed:    Yes

Following was active at lid closing time: Mail, Skype, Chrome (with 10 tabs)

Found a suggestion to address the:

 Idle sleep preventers: IODisplayWrangler

by removing/resetting Printers and other stuff https://discussions.apple.com/thread/7275550?start=0&tstart=0 No help.

Update: Running log show --style syslog | fgrep "Wake reason" shows noting in the hours of interest!

Manual method: Review Console system log ... Found huge activity from Google Chrome reporting errors

Aug 16 01:22:29 myMBA Google Chrome[18176]: objc[18176]: __weak variable at 0x600001228a50 holds 0x2121212121212121 instead of 0x600000c279a0. This is probably incorrect use of objc_storeWeak() and objc_loadWeak(). Break on objc_weak_error to debug.

and Google Software trying to do update on repeated basis?

Aug 16 01:40:11 myMBA GoogleSoftwareUpdateAgent Closed Chrome overnight, still the same.

More investigation (and it repeats following every 30 second all night long):

pmset -g log

UUID: C67362CF-C70A-4AC3-AB1E-EC803FD0563F
2017-08-18 04:53:46 -0700 Notification          Display is turned off                                                                 
2017-08-18 04:53:46 -0700 Assertions            PID 117(hidd) Summary UserIsActive "com.apple.iohideventsystem.queue.tickle.4294968070.3" 07:57:39  id:0x0x90000926c [System: DeclUser kDisp]          
2017-08-18 04:53:46 -0700 Assertions            PID 50(UserEventAgent) Summary BackgroundTask "com.apple.mds.3" 36:06:15  id:0x0xb00008082 [System: DeclUser kDisp]          
2017-08-18 04:53:46 -0700 Assertions            Kernel Idle sleep preventers: -None-          
2017-08-18 04:53:46 -0700 Assertions            PID 62(powerd) Created InternalPreventSleep "com.apple.powermanagement.darkwakelinger" 00:00:00  id:0x0xd0000937e [System: PrevIdle DeclUser SRPrevSleep kCPU kDisp]          
2017-08-18 04:53:47 -0700 Assertions            Kernel Idle sleep preventers: IODisplayWrangler          
2017-08-18 04:53:47 -0700 Notification          Display is turned on                                                                  
2017-08-18 04:53:49 -0700 Kernel Client Acks    Delays to Sleep notifications: [AppleBacklightDisplay driver is slow(msg: SetState to 0)(984 ms)] [AppleIntelFramebuffer driver is slow(msg: SetState to 1)(420 ms)] [AppleHDADriver driver is slow(msg: SetState to 1)(409 ms)] [AppleHDADriver driver is slow(msg: SetState to 1)(441 ms)] [AppleIntelFramebuffer driver is slow(msg: SetState to 2)(1027 ms)]           
2017-08-18 04:54:01 -0700 Assertions            PID 62(powerd) TimedOut InternalPreventSleep "com.apple.powermanagement.darkwakelinger" 00:00:15  id:0x0xd0000937e [System: DeclUser SRPrevSleep kCPU kDisp]          
Sleep/Wakes since boot at 2017-08-16 16:47:11 -0700 :0   Dark Wake Count in this sleep cycle:1

Problem remains, something is draining the battery. How can I prevent this drain from happening?

  • 1
    While I may guess what your question is, can you please add it for clarification? :) (What causes my battery drain? / How can I prevent my battery to drain while sleeping?)
    – oa-
    Commented Aug 16, 2017 at 12:35
  • @oa- just did for OP :))
    – owlswipe
    Commented Aug 16, 2017 at 17:24
  • Close Chrome and try again next night?
    – nohillside
    Commented Aug 16, 2017 at 20:37
  • Sorry, forgot to say, I did close Chrome last night :( still the same.
    – Ruskes
    Commented Aug 16, 2017 at 21:02

2 Answers 2


Finally, I got it to obey when I say sleep !

The battery remained at 100% charge after 8 hours of sleep.

This is what sleep should look like between 1AM and 10AM. That's it, no other activity as it should be.

Aug 19 01:05:19 myMBA com.apple.usbmuxd[4793]: notice    Idle, stopping.
Aug 19 01:05:19 myMBA com.apple.usbmuxd[7126]: notice    usbmuxd-374.913 on Mar 17 2017 at 17:43:50, running 64 bit
Aug 19 01:05:54 myMBA com.apple.xpc.launchd[1] (com.apple.xpc.launchd.domain.user.501): Service "com.apple.xpc.launchd.unmanaged.loginwindow.113" tried to hijack endpoint "com.apple.tsm.uiserver" from owner: com.apple.SystemUIServer.agent
Aug 19 01:06:24 --- last message repeated 3 times ---
Aug 19 02:16:35 myMBA syslogd[51]: ASL Sender Statistics
Aug 19 09:52:58 myMBA syslogd[51]: ASL Sender Statistics

So what did I do? First it killed the pesky GooleSotwareUpdate (as described here) Pesky Google acting up .. that was active all night long and completely ignoring my sleep request. Then I shut down all apps (especially the Google Chrome that was misbehaving). Then I Left the Lid open and used the Sleep now command (in Apple top left) The reason for Lid open was to see if monitor comes on after a while, and it did ! I had to use the Sleep command 3 times, since it came back on about 3 seconds after ?


Ok so you want to find out what's eating 5-10% battery in 8 hours. Well first we need to go over how computer hardware works.

Following was active at lid closing time: Mail, Skype, Chrome (with 10 tabs)

Note that software kept in the memory during sleep mode (when closing the lid) will use electricity because current day NAND Flash memory uses electricity to retain the information. This is a problem with NAND, unlike your Hard Drive or other technology currently under experimentation such as Milipede Memory or CBRAM, which all use permanent forms of data retention, DDR Memory requires electricity to exist.

For example, my 2008 MacBook hand-me down is still working find in 2017 albeit it will go from 100% to 25% in 24hrs due to the cycle count of the battery and the drainage caused by the memory and occasional wake-ups from LAN pings or whatever else. It's the second battery we've installed but I'm happy with the dual core on the go. If you were to plug an electric meter into your wall outlet and then plug an iMac into that, you would note even on sleep or "Hibernate" you will see minute amounts of power usage. The laptop actually shuts down it's cooling system with the lid closed unlike older iMacs that will often keep their cooling system powered.

Your "Activity Monitor" app in the Utilities folder will allow you to see what software is using the most power, but a good practice is to shut down non-essential software before closing the lid. Do not plug in the laptop overnight IF it has a Lithium Ion battery, those batteries prefer micro-charges and keeping them "topped up" will stress them out, similar to your phone battery. Check your battery type for proper maintenance or "treatment" of the battery for the best battery life. :)

  • thank you for your response, however, I did a experiment and it slept all night, with battery still showing 100% charge in the morning. The way it should be. As for NAND and RAM; RAM cells need constant refreshing, however NAND FLASH cells can retain data for years together.
    – Ruskes
    Commented Aug 19, 2017 at 19:28
  • NAND Flash storage cells yes that is true. As you know with limited writes. Thank you for adding that information. Also that's excellent that your laptop held it's charge, hopefully it didn't drop 5-10%, my laptop occasionally does that after a few moments.
    – Tmanok
    Commented Aug 20, 2017 at 18:28

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .