Mountain Lion (OS X 10.8.1) Update Improves Battery Life; But Still Not Back to Lion (OS X 10.7.4) Levels

BY Rounak Jain

Published 24 Aug 2012

Apple’s Mountain Lion OS X release saw record adoption numbers in the initial few days of launch, but it also brought with a few bugs, the most noticeable of which was a substantial decrease in battery life of MacBooks.

According to tests conducted by MacObserver, OS X 10.8.1, the newly released maintenance update for Mountain Lion, does improve upon the drop in battery life, but not enough to bring it to pre-Mountain Lion levels.

MacObserver tested battery life on MacBooks running OS X 10.7.4 (Lion), OS X 10.8 and OS X 10.8.1. Their testing process was:

  1. Open TextEdit, pause 10 seconds.
  2. Open Safari and navigate to a content-heavy website (, pause 20 seconds.
  3. Navigate to a second content-heavy website (, pause 20 seconds.
  4. Open Mail, pause 10 seconds to allow any messages to download
  5. Close all open applications
  6. Log a time stamp to a text file
  7. Repeat

Their results:


Build 12B17 was the developer release of the OS X 10.8.1 update, while build 12B19 is the public release. Removing the Wi-Fi icon from the menu bar was a fix suggested by a MacObserver reader, which obviously didn’t work.

As the chart shows, there’s still a one hour difference in battery life between Lion and the newest release of Mountain Lion. Apple’s expected to continue improving upon battery life in the 10.8.2 update, which has already been seeded to a few developers.

Have you experienced improved battery performance after upgrading to OS X 10.8.1?