We decided to also run tests on our 2012 15-inch MacBook Pro with Retina Display (rMBP). We privately tested each beta build of 10.8.3 on both MacBooks as they were released and, starting with build 12D76, we saw a noticeable jump in battery life on the rMBP. Running time went from 398 minutes, which was roughly the same as the public release of 10.8.2, to 421 minutes, a change that persisted with the final build. These are averaged results that we ran three times to confirm.
The site also tested other MacBooks including the 2011 MacBook Pro and 2011 13-inch MacBook Air; however, neither machine saw a similar increase in battery life.
Read More [via CultofMac]