The current beta of OS X 10.8.1
may substantially improve MacBook battery life for some users, an anonymous developer indicates. The person says
that before installing v10.8.1, his MacBook was only displaying a battery life of four hours and five minutes on a full charge. Afterwards, however, that number shot up to over eight hours, more than what Apple advertises for any MacBook model.
Since Mountain Lion's release, some users have complained about losing battery life after making the upgrade. Apple staffers have allegedly reached out to customers posting in the company's support forums, trying to gather system data in order to address the problem. At the same time, some people have actually had their reported battery life increase after installing the OS.
Battery life is not listed among the areas Apple is asking developers to concentrate testing for v10.8.1. Instead, developers are being asked to focus on areas like Microsoft Exchange support, and using a Thunderbolt Display. It's uncertain when the final version of the update might reach the public.