Edit: After half day, my wife’s Mac started having the same problem. I have then applied the solution that I found in the Apple
Mountain Lion Users Reporting Battery Draining Issues
After resolving the wide spread WIFI issue we have heard from a couple of Macbook Pro and Macbook Air users who are telling us that the OS X Mountain Lion upgrade has had a dramatic effect on the battery of the Macbook’s
Eric got in touch with us to let us know that he thought he was all set to go when he had fixed the WIFI issues on hit late 2011 15″; Macbook Pro but he was then faced with a massively accelerated battery drain since the upgrade. Within just an hour his Macbook Pro’s battery had lost around 30% from a 100% charge. The Macbook Pro was only running Google Chrome, the official Mail application and activity monitor which showed that the CPU was 96% idle and also the fan were not running. This means it could only be a bug / leak in OS X Mountain Lion its self.
There has also been a lot of people getting in touch about similar problems with Macbook Air’s
We are hearing of quite a few bugs / issues with in OS X Mountain Lion and we are expecting these to be fixed within the OS X 10.8.1 update coming soon
@MacReviews New Mountain Lion is killing my new MBP Retina…..fan is constantly on and you can watch the battery drain away…
— Adrian Cunningham (@Crafty_B) July 28, 2012
@MacReviews my 2009 macbook is now useless, I’m lucky to get 20 minutes out of a full charge, and it’s overheating !
— chris (@chrisbates65) July 28, 2012
If you are having any issues with OS X Mountain Lion be sure to let us know
OS X Mountain Lion