Earlier this month we conducted extensive testing on OS X battery life from Snow Leopard through the developer builds of Mountain Lion 10.8.2. The results of our tests showed that both Lion and Mountain Lion decreased battery life upon their release, with Mountain Lion notably causing a painful 30 percent reduction in running time that persisted through 10.8.1.
The developer builds of 10.8.2 showed a dramatic improvement, restoring all of the lost battery life and even adding a few minutes of running time. We were hopeful that this improvement would persist to the final release but, with all beta software, nothing can be guaranteed.
On Wednesday, Apple released the final builds of 10.8.2 and 10.7.5 to the public. We anxiously fired up our test MacBook Pro and ran tests on both updates. Here are our results (new tests highlighted in red):
Users will be happy to see that both 10.7.5 and 10.8.2 maintain, and even slightly improve battery life. We now feel confident recommending that users concerned with battery life upgrade to Mountain Lion, with all other considerations being equal. We hope that Apple won’t release future builds of Mountain Lion that negatively impact battery life, but we’ll keep our eyes peeled for 10.8.3 and test it and future updates as they are released.
For a full description of our testing methodology and hardware, check out our original report on battery life.