Battery Life Improves Dramatically in OS X Mountain Lion 10.8.2

Sep 20, 2012 - 36 Comments

Battery Life in OS X Mountain Lion 10.8.2 improved dramatically

OS X Mountain Lion has been a fantastic update for Mac users, but some of us on portable Macs discovered an annoying side effect of reduced battery life, often accompanied by a Mac that felt warmer to the touch. Those issues have been largely fixed with the OS X 10.8.2 update, making it a must-have update for MacBook owners.

The following observations are anecdotal and not scientific by any means, but findings thus far with OS X 10.8.2 include:

  • Dramatic improvements to battery life on three different MacBook Airs (2010, 2011, and 2012 models), each jumping by at least 2 hours to an average of 6 hours under normal use
  • Portable Macs running OS X 10.8.2 appear to run at lower temperatures and are noticeably cooler to the touch, perhaps suggesting the original battery life issue was related to power management or an errant background process

The largest boost was found on a 2011 MacBook Air 11″ model, which jumped from 3.4 hours to 6 hours on a full charge. This was shown by the Battery Time Remaining app and proved accurate while running a clock to observe battery drain under standard usage conditions at 70% display brightness.

Interestingly, the release notes of 10.8.2 make no mention of battery improvements, but if you have experienced any reduction in battery life with Mountain Lion then updating to the latest version will demonstrate very obvious increases. The difference in battery performance between OS X 10.8.1 and 10.8.2 is night and day and should give users who suffered under prior versions at least an hour or two longer while on the go.

If you have a MacBook, MacBook Pro, or MacBook Air running Mountain Lion 10.8 or 10.8.1, install the OS X 10.8.2 update right away through the  Apple Menu > Software Update, and enjoy the immediate battery boost.


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Posted by: Paul Horowitz in Mac OS, Tips & Tricks, Troubleshooting


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  1. noob_for_life says:

    I just put in a new battery, thinking that it was dying. I’m getting the same poor performance since upgrading to 10.8 (from Snow Leopard). Right now, Activity Monitor says I’m at about 90% idle and the display on my early 2011 MBP is below 70%. But, the system was predicting 2hr 40 min left in the charge. The charge has gone down 3% in five minutes.

    I easily got 3 – 4 hours/charge prior to this upgrade.

  2. Slawix says:

    After I add an 8GB memory instead of 4GB, live time for my MBP 2009 increased from 3-4 hours to 6 hours. I don;t shure it’s the reason, but the fact is.

  3. Rob says:

    My MBP early 2009 lost 2 hours going from Lion to Mountain Lion with no improvement seen on 10.8.2.

  4. John says:

    While my 2011 Macbook Pro did show some improvement after 10.8.2 update. I must say it did so only in web surfing and low resource tasks. When I play video like Hulu or Netflix I still get much less battery life then I would expect even for video playback. So while I think Apple did a good job improving a bad situation. I believe all Apple did was try and teak ML so as to better disguise the battery drain. I do not believe they really solved all of it. At least not with my Macbook Pro.

  5. NickM says:

    Battery life on my MBP Mid 2009 has reduced considerably
    and I’m getting a Service Battery message despite only 490 cycles !!

    Had been looking at a new MBP but now getting cold feet !

  6. brendonj says:

    I updated to this 10.8.2 on my 13″ early Macbook Pro and battery the time stayed between 4 and 6 hours. I had enough, I backed a few things and rolled back to osx lion after a battery calibration and update to 10.7.5 I’m back in business. Looking at 10:30 to 11:00 while surfing and 6:30 to7:00 while watching a movie. I will be staying with lion.

    • Tony says:

      Life in OS X Lion is the best! and on Mountain Lion it has gotten more worse, Death of Steve Job it made Apple worse :( During Steve Jobs era was good and i bet Steve doesn’t like to disappoint people when there is issues and Steve puts pressure on Tim Cook to fix the issues much quicker.

      I hope Apple will continue to be like the day during Steve Jobs’ era!

  7. Maniraja says:

    My battery life was pants after the 10.8.2 even worse until did three of those battery reset things (which i’d tried to no effect on 10.8.1. Now back to how it was few, seeing the % drop like a stone even with everything off was doing my nut in. Hope it works for you.

  8. Daleok says:

    Early 2011 MBP. No change in battery life after 10.8.2. Carrying around my power cord more than usual.

  9. Positron says:

    late 2011 15″ i7

  10. Positron says:

    My battery life went up to 11:05 hrs. However, I installed it using a USB stick with 10.8.2 on it. I erased my SSD using disk utility. Then installed on a clean drive. When I started with 10.0, I had 8 hrs. I’d did the above process when10.8.1 came out and battery life went up to 9 and a half. Now, after 10.8.2, I have 11:05 hrs. Not bad apple. Who knows what that means in the real world though. We’ll see …

  11. Shawn says:

    MB Air 2011 11″.

    Updated to 10.8.2 and battery life is still awful.

    Have Safari open as well as MS Word 2011.

    Battery life at 90% says 2hr 39mins.

  12. Brian says:

    Battery health has definitely decreased from 98% to 90% losing a total of 658mAh with this update. iStat pro and Coconut battery are both reading the same cycles, charge and health read outs though the os x battery read out is giving me a charge remaining time inconsistent with its percentage or that of the above applications. That said some 10mins after a reboot the readings of iStat pro and the inbuilt os x start to change, I now have 5hrs 22mins remaining at a 78% charge, how wonderful, no wait… wait 4hrs 53mins, no 4hrs 11mins and thats 5hrs again. Has a macbook battery ever exploded???

  13. Brian says:

    Olds ghosts have returned to haunt the MBA Late 2010. I’ve see a significant drop in battery life. Quite hard to tell really where I stand as it keeps changing. At worst health dropped to 16% with a 2hr life fully charged and at the time of writing, after resetting the SMC its now at 90% health with battery life performing normally. This is changing as I go along, after the 10.8.2 update it stated that I had a service battery, fixed after a SMC and fixed permissions reset though no health/life increase, though now it seems that the life has jumped up enormously after my second reset. Second reset and nothing happens, check osxdaily for conversations and boom, battery returns to normal. I’ll repost what dark and strange journey my battery is taking with this damned bloody lion pursuing its ass. Oh I see, percentage likes to go down, time remaining likes to go up then???

  14. Rullator says:

    No improvement on my MBP (early 2011, 2.2Ghz i7 8Gb) battery. I´m turning back to Lion….I´m pis… angry!!

  15. Mark Evans says:

    Has Apple released any information about how this update ACTUALLY WORKS? Closing misbehaving threads? Reducing CPU clock cycle? Automatically dimming screen? Other? Yes, it’s great to have more battery life, but that’s like saying your food will last longer if you only have one small meal a day. (OK, maybe not that level, but you get the idea.)

  16. Winski says:

    No, it didn’t… for me…. MBP mid-2009 – SAME…AWFUL…

  17. Janichsan says:

    I see no improvement at all. On my brand-new Retina MBP I had only about 4 hours battery life before the update and after updating I still have only about 4 hours battery life.

  18. finn says:

    Do I need to do some kind of battery calibration to see the full effect of the update? Or should it just show the increased battery life right after the update?

  19. andy says:

    wait does this +2 hours work when upgrading from lion to this version of mountain lion as well?

  20. Kr00 says:

    My late 2009 MacBook Pro began giving me a battery warning, to replace the battery, after the 10.8.1 update. Now in 10.8.2, its gone. Now I don’t have to worry about replacing the battery, just yet. Whew!

  21. ramz says:

    It’s a great update! My MBP has been working for 6 hours perfectly. Before that I could not use it for more than 4:30 hours.

  22. Mike says:

    It fixed mine but now Chrime won’t load and if it does it gets stuck and freezes. Only way to fix it is to force it to shut down.

    • BrianM says:

      I’ve seen this happen with Chrome if Plex is running on the computer (the client specifically, the server doesn’t cause it). Safari & Firefox were not affected.
      There may be other apps running that affect Chrome like this as well

  23. unixgeek80 says:

    I have a mid 2010 MBP and everything is working like a champ im loving it

  24. Niladri Haldar says:

    With my mid-2010 MBP, a victim of the non-ending Kernel panic issue with Graphics card switching, I am seeing NO improvement.

    Plus now I have Wifi connectivity getting worse. God knows what had He bestowed upon me with this MBP. Am I the odd one out?

    • Niladri Haldar says:

      No improvement in battery, and worse Wifi reception.

    • Josh says:

      Niladri – take in in to apple quick smart! there was an issue with the mid-2010 models (15′ MBP) were the graphic card caused what your experiencing. Apple then extended the warranty for an extra year for these issues, mine was outside the extra year but they made an exception – its worth a shot.

  25. Si RyAaann says:

    I have a macbook pro 2007 and it looks like im only saving 30 minutes. before 100 is 2 hours now its 2:30 remaining

  26. Nicholas Sanders says:

    I’m happy for those who are seeing improvement but it isn’t universal – my late 2010 Air is showing just 3 hours on a 100% charge.

  27. Marcus says:

    1:30 to 2 hour boost here on MacBook Pro, HUGE improvement! This is awesome!

  28. norbs says:

    Haha nice I have the 2011 MBA, i think I already got used to the battery life.

  29. john says:

    I have definitely seen a better life battery on my MBA or mid2011.
    What is this application on the screenshot, displaying battery cycles, temperature, etc?

    • Nicko says:

      It looks lke an App called “Battery Time Remaining”.

      My 2011 MBP show about a 2 hour boost.

      • Chris says:

        They linked “Battery Time Remaining” in the article. It’s a nice app. You could also try Coconut Battery, which provides even more information about the battery

        • john says:

          sorry, read the article in a hurry.
          I already use coconut, but this app looks nice since it’s integrated in the battery icon.
          but thanks for the help.

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