I left my Model S in Florida garage two days ago. I'm in NY until January. I thought I left it plugged in, with 50% charge limit, at 20A. However, it's not communicating now. The App thinks it's communicating but it's not. It shows an empty battery with ---% (Dashboard app says "Not Charging"). I've never seen this before. Anyone know what it means? I'm concerned for battery drain over 2 months. It appears the car is completely shut down. Is that possible? At this point, it should still have near 50% and no reason not to respond. Any thoughts?