Since the first complaints surfaced in an Apple Support Communities thread started on July 25, the day Mountain Lion launched, the number of reportedly affected MacBook Pro and MacBook Air owners has grown to the point where Apple has supposedly initiated an investigation. As of this writing the thread, titled "Battery life dropped considerably on Mountain Lion" now stands at 15 pages.
While most users are seeing battery life drops of about one to two hours, some cases claim performance has fallen to less than 50 percent as their machines are only capable of staying on for a little over two hours.
Community members have been trying a variety of methods to remedy the issue, from re-installing the software to turning off some of Mountain Lion's new features like Power Nap, but the attempts have yet to produce a fool-proof solution. Some members have seen limited success in resetting the machine's system management controller (SMC), though the battery issue crops up again after continued use.
Many users are reporting heightened CPU temperatures even when the machine is at idle, possibly pointing to a backend program management problem, while others are seeing battery drain when the system is sleeping.
The troubles with Mountain Lion mirror those seen when OS X 10.7 Lion was released last year. In that case, a huge 176-page thread was created regarding MacBook Pro battery issues and the problem is still unresolved for many Lion users.
Apple has taken notice of the most recent complaints and, according to one community member, sent out a questionnaire on Friday in an attempt to pinpoint the problem.
OS X Mountain Lion launched last week, bringing with it over 200 new features including tighter iCloud integration, the Messages app, Notification Center, Facebook integration, Dictation, AirPlay Mirroring and Game Center.