Some applications will cause a clean OSX install to switch to the discrete graphics card, even while you are running on battery. For me the tipping point was Ch

Some applications will cause a clean OSX install to switch to the discrete graphics card, even while you are running on battery. For me the tipping point was Chrome - as soon as you hit a site with flash, the discrete graphics is enabled, and doesn't get disabled until you kill Chrome entirely (there was a bug about this that was WONTFIX at one point, not sure what happened). Your choices at that point are either disable flash, live with having your batter life cut in half, or install GfxCardStatus to enforce a saner policy. Edit: Here is the bug I mentioned: http://code.google.com/p/chromium/issues/detail?id=43706 http://code.google.com/p/chromium/issues/detail?id=43706