I have a mid-2012 MBA that is almost two years old. I remember that when I first got my MBA I could sit on my couch for hours and the laptop never got hot. When I now use the MBA while sitting on my couch the base / bottom gets hot to very hot quickly...the battery health is 83% with 92 cycles. Would appreciate feedback as to what this means...is my battery dying to the point where the MBA will only work when plugged in (as has happened to my friends' older MBP), etc. TIA.