I have a 2012 MBA with about 250 cycles on the battery. It has always lasted 6-8 hours and the battery health app said 83% until last night. I left the laptop in my car for about 2 hours in -15°F conditions. When I got it out and turned it back on it was very cold, and battery health said 63% life and the battery indicator said "Service Battery". It kept saying that even after the comouter warmed up to room temperature. I let the battery run down to 0 to calibrate it overnight then plugged the mac back in. The LED on the charger is now green. I haven't turned it back on yet to see if it will charge. Help? I would hate to have to send this in to Apple when it had a perfectly good battery up until yesterday. The nearest Apple store is 150 miles away.