I'm just curious, but can anyone tell me what I can expect from one of the newer macbooks battery wise from a blindness perspective? IN other words, turning the screen brightness down, deactivating bluetooth because I won't need that, and any other unnecessary things? The web site I think estimates around 5 hours, but I think that's with everything on. Not sure. But I will be getting my macbook soon, and am wondering if I will need an extra battery or not for it. Thanks in advance, Jerry