My macbook air (13-inch, mid 2011) battery drains from ~100% to ~85% over night. The problem only started a few months ago. I'm currently running yosemite, but the problem started while on mavericks. My battery cycle count is ~130.

I tried completely discharging the battery and then re-charging, but that seems to have had no effect. I've also read through apple's battery documentation, but I can't find anything there either. Unfortunately, most of the forum posts I've found are about batteries going from 100% to 1% overnight -- I'm having trouble finding anything about losing ~15% overnight.

Results of pmset -g

Active Profiles:
Battery Power       1
AC Power        2*
Currently in use:
 standbydelay         4200
 standby              1
 womp                 1
 halfdim              1
 hibernatefile        /var/vm/sleepimage
 darkwakes            1
 networkoversleep     0
 disksleep            10
 sleep                10
 hibernatemode        3
 ttyskeepawake        1
 displaysleep         10
 acwake               0
 lidwake              1

Here are the results of syslog | grep -i "Wake reason" for the last 24 hours. I put my computer to sleep yesterday around 6pm and woke it this morning at 9:56am. Over that period, the battery went from 100% to 85%.

Nov 18 09:51:00 prime kernel[0] <Notice>: Wake reason: EC.LidOpen (User)
Nov 19 09:56:57 prime kernel[0] <Notice>: Wake reason: EC.LidOpen EHC2 (User)
  • 1
    We need a piece of information from you. in Terminal type "pmset -g" and paste the result here.
    – Ruskes
    Commented Nov 17, 2014 at 17:48
  • Added -- happy to add any additional info. Commented Nov 17, 2014 at 17:54
  • How about Power Nap, is that disabled too?
    – Shane Hsu
    Commented May 8, 2015 at 11:27

10 Answers 10


I have had the same problem occur to me after a completely new battery was installed in a MacBook Air from late 2011. From 100% I woke up the next day to find the battery at 28%.

So I dug up some research I had done and it comes to this command:

sudo pmset -a hibernatemode 25

From examining your setting I see yours is not 25 but 3, if you have not found a solution for your problem, this could be it.

Here is some additional read on this from the Apple Discussion Forums: https://discussions.apple.com/thread/4729695?start=0&tstart=0

You can see some pros and cons of doing this. I quote the documented differences:

hibernatemode = 3 by default on supported portables. The system will store a copy of memory to persistent storage (the disk), and will power memory during sleep. The system will wake from memory, unless a power loss forces it to restore from disk image.

hibernatemode = 25 The system will store a copy of memory to persistent storage (the disk), and will remove power to memory. The system will restore from disk image. If you want "hibernation" - slower sleeps, slower wakes, and better battery life, you should use this setting.

If I notice better results I shall do well to post them here as backing evidence. Good luck!

  • Thanks! I'll give this a shot. I ended up completely reformatting my machine to see if the issue would resolve itself -- unfortunately, the same thing continues to happen. Commented Jan 12, 2015 at 19:47
  • Hello again, I think I am due for a short update; with mine, now almost 7 months in, I am still enjoying the benefit of the sudo pmset -a hibernatemode 25. So I can testify it works and now I can happily travel and not run out of battery power between meetings.
    – LAK
    Commented Jul 29, 2015 at 12:13
  • 1
    To be honest the only option that fixed this problem for me was resetting the SMC. Of course I also disabled bluetooth, networking and notifications during sleep first.
    – andreszs
    Commented Jan 7, 2019 at 23:02

To better understand what is it doing during the sleep and what is consuming your battery:

Your system is set to absolute sleep (no activity at all) for 4200 seconds (that is standard)

You have the "womp - wake on ethernet magic packet" enabled.

Unless you need that, you can disable it with sudo pmset womp 0

You can look up the reason for wake by using the following in Terminal

syslog | grep -i "Wake reason"

More details are in the Console log.

Look for activity that happens after you initiated the sleep and it starts about 4 hours after sleep begins with message like:

kernel[0]: Wake reason: EC.SleepTimer (SleepTimer)

Now look what is it doing after that line.

  • Posted the output from syslog -- doesn't look like anything incriminating, however. Could it just be a bad battery? My (naive) guess ruled that out due to the battery maintaining full charge if I do a full shut-down vs. closing the lid. Commented Nov 17, 2014 at 18:58
  • It is a combination of Battery, but also the reasons it wakes up that consume battery. As you can see you have the "Wake reason: RTC (Alarm)" going about every 2 hours. That will add to battery drain.
    – Ruskes
    Commented Nov 17, 2014 at 19:35
  • RTC (Alarm) doesn't seem to happen when it's on battery-power, though. Is it possible for the battery to drain 15% overnight without waking from sleep? Commented Nov 17, 2014 at 19:39
  • Nope, if nothing is going on a good battery should not drain more than 5%. I am confused, are your logs from battery or from power or mixed?
    – Ruskes
    Commented Nov 17, 2014 at 19:43
  • 3
    NOTE: Most system logs have moved to a new logging system. See log(1) for more information. Commented Jan 19, 2017 at 23:57

I had the same problem with my MacBook Air. Tried different settings etc, didnt work. Then I noticed one pattern - If I had Chrome running, then this happens, but if I had quit chrome before closing the lid, then battery remains. So, thats what I am doing now. Making sure Chrome is not running when I close the lid.

  • very strange behaviour .. when you close the lid, the MBA should just keep memory alive. Having Chrome or any other tool should not change the battery drain. Or maybe it uses less energy if less RAM is used ?
    – Fredv
    Commented Jun 17, 2016 at 19:15

When any computer is asleep it still uses power to keep the ram fresh. Another thing that macs do is to occasionally check for new emails and notifications even while asleep. This feature is called power nap. To turn that off, visit https://support.apple.com/en-us/HT204032 for information.

Leslie's advice will help even more with using hibernate instead of sleep.


I had this issue with my new MacBook Pro once. I found that I had NoSleep enabled (even with the app closed). If you have NoSleep installed make sure you turn it off.


I had this problem with my MBP and iMac 5K (wake up in sleep mode automatically. It was actually the Google Drive app's fault; after I removed it, the problem was solved.


I had same issue, culprit was flux app. I disabled flux app and all os back to normal for me.


I add another important reason: macbook Pro will not hibernate if SSD start up disk is installed in the optibay (in those models that used to have one).

The "symptoms": MacBook just didn't hibernate, did not turn off automatically after autopoweroff minutes in pmset, nor turned off if scheduled. The consequence of this, a very important battery drain overnight (around 5% per hour) that I just wasn't able to solve applying any pmset setting combination / SMC reset / PRAM reset / macOS clean installation / previous macOS versions. I also spent several hours trying to determine if any startup process prevented deep sleep / hibernation... nothing seemed to work, so I almost gave up and attributed this to a hardware malfunction.

But... the culprit was a start up SSD disk installed in a case replacing the superdrive, that is to say, installed in the optic bay.

I simply changed the disks places, with the start up SSD connected to the native disk bay, and the issue was solved!

Hope it helps!!


I had the same problem with MacBook Pro 13in 2017 model. But the battery drain and laptop being warm happened only when the laptop was sleep and the charger was connected but turned off. I didn't observe the problem when the laptop was disconnected from the charger during sleep.

So, I guess it must be an electrical issue(earthing).


Basically, there are a number of apps, processes, settings etc that can prevent your mac from sleeping. I wrote a little function that I have added to batch_profile and run manually to sleep my computer. If sleep is being prevented the function will produce an audio alert.

(note, it automatically closes apps that I know always prevent sleep and it also turns off bluetooth which is also often a problem).

function slx {
  echo "...stopping any backups, closing any programmes known to cause issues"
  tmutil stopbackup
  pkill -x qemu-system-i386
  pkill -x qemu-system-x86_64
  pkill -x Music
  pkill -x VLC

  echo "...turning off bluetooth & ejecting external drive"
  blueutil --power 0
#  diskutil eject /Volumes/SanDisk512TimeMachine

  while true; do
    if [ $canSleep -eq 1 ]; then
      echo "success"
      if [ $retry_count -eq $max_retries ]; then
        pmset -g assertions
        blueutil --power 1
        say "cannot sleep"
        echo "cannot sleep"

      echo "...trying again"
      sleep 4

extractpmset() {
  pmset -g assertions | awk 'NR>=3&&NR<=10' | grep -v "UserIsActive" | grep -v "ExternalMedia"
  #pmset -g assertions | awk 'NR>=3&&NR<=10&&!/UserIsActive/'

isPreventingSleep() {
    if [[ $output == *"1"* ]]; then
        echo "1"
        echo "0"d


You can also read man pmset and run pmset -g to check all your settings. I went through every single one, changed a few and it seemed to do the job.

Also you can run pmset -g assertions to check if anything is preventing sleep. On my machine ExternalMedia says it prevents sleep but in actual fact I don't think it does so I've excluded that from the list of things that could be preventing sleep.

IMO, the function is what the mac should do automatically when you select sleep.

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