I am posting because I currently have a 15'' Macbook Pro (Early 2011 edition) and have suffered from poor battery life since upgrading from Mac OS X 10.7 to 10.8.
Before the upgrade, I could use my MBP for around 7 hours when I turned off the discrete graphics card (using gfxCardStatus), dimmed the brightness and switched off the WiFi / bluetooth adapters. Using the same settings today, I can scrape at most 3.5 hours of battery life.
Some of this is due to the fact that my battery is 2 years old and has been through 475 charge cycles. That said, the Battery Health app says that my battery should still be able to carry up to 85% of it's capacity, so I would expect around 6 hours of usage at least.
I believe that the remaining decrease in performance is just linked to software changes in Mac OS X 10.8 that automatically turn on the discrete graphics card.
Any advice that can improve my battery life would be very much appreciated. That said, my questions are:
Is there a way to permanently turn off the discrete graphics card in Mac OS X 10.8.2? I used to be able to do this using the gfxCardStatus app in Mac OS X 10.6 and 10.8. Unfortunately, however, it does not work in 10.8. This is frustrating since the discrete graphics card turns on automatically whenever I run an app like VLC which uses OpenG. I hear this is to make sure that apps which use OpenGL run smoothly... but VLC already runs smoothly on computers with only integrated graphics cards... so what the hell?
Am I right in believing that the battery life issues are related to the way that Mac OS X 10.8 handles the graphics card switch? Another culprit could be that I replaced a few of my MBP parts myself a few months ago. In particular, I upgraded the RAM on the machine from 8 GB to 16 GB, installed a 512 GB SSD (which was supposed to be more energy efficient), and also removed the CD / DVD Drive (did not install anything in its place). Is there any way to tell?