Sorry if this thread has been done to death, but I'm too lazy to search My 2012 MBA is getting really bad battery life and I don't know why. It's only like 9 months old. I can just be web browsing and my estimated battery life with drain to less than 4 hours within like 30 minutes of unplugging it (half brightness). When I open up Battery Health it will tell me my current usage and it will be substantially lower than "Web Browsing" even though that's all I'm doing. I mean I have some apps open like Mail or Twitter in the background but they aren't even active. Activity Monitor shows nothing with high CPU usage either I remember watching the video a while back where they showed "App Nap" or something like that? How much does it actually help?