One month ago a message appeared in my Model X that stated: 12V Battery Needs Service. Replace 12V battery soon. New England Tesla Mobile Service notified me that these 12V batteries are on back order. Tesla Service in Dedham, MA informed me that they do not have these batteries either. Does anyone know how long I can continue to drive my car confidently with such battery status? Am I at risk of getting stranded when I am on an extended trip? Are these batteries really on back order everywhere? Lastly, since this message has appeared, I cannot perform a software upgrade. Does the software upgrade rely on a well functioning 12V battery? Thanks.