Okay. Some of the 2013 MBA say they last 12 hours, some 15 and some only 7-8 hours. I found this in another thread and it works! First my MBA is an i7, 8gb ram, 256 and the battery indicator only read 7-8 hours, not 12+ like others. Here's the solution. Charge the battery 100% full. Unplug Restart computer (at this point, the battery life should read higher) drain the battery to 0% Leave it for 2-3 hours. repeat above again. Do this 1-3x and next time your battery is full 100%, you can right cilck it and it will say 12+ hours! I havne't tested it to see if it lasts 10+ hours...i'm doing that now... Currently lasted 2.5 hours and it went from 100% to 77%. So looks like it's on its way to 10 hours. (with youtube music), 2 clicks on keyboard brightness, and half full on screen brightness.