Here in Minnesota we've had a snap of cold temperatures and then a snowstorm/turned blizzard. I decided, since I own a Jeep Wrangler, to use that vehicle for the past week. Since I did not want to leave my 500e sitting at 100% charge for several days, I did not charge it after its last use. I parked it in the driveway at 83% charge. Today, a few days later, I checked the charge and it was only 52%. Normally the car holds charge. My thought was several days ago the temperature dropped to -14F in the morning. Perhaps the car came out of hibernation and heated the battery pack? Does the car do this in extreme low temperatures? So... something to be aware of is to check the car often if not plugged in and the temperature gets extremely cold.