That is good to hear. Mine crappy lead acid battery did fine with the temperatures, but I also have a smart charger on it. Now handling the draw from my amp is a different story.
I know similar questions have been asked but all I could find was around -20 to -30 degrees., but -50 is a whole different animal. I just want to make sure. From what I have found I feel pretty comfortable with the performance ability of the xs power batteries but I just want to make sure.