Thanks for the information Fish. I do have a charger with which I will try to charge the battery.
Did you charge it thru the trunk or the engine compartment? The condition is most likely caused by a combination of my not putting enough millage on the car and the cold weather. However, this is my second winter with the car and I did not have any issue last year. Perhaps there is a problem with the battery. I will charge it and see.
2011 550iX GT, 2011 MB C300 sport, 2003 Porsche C2 Cab (turbo conversion)