HELP 700mi From Home Carging system wont charge

Hello i am in Baggs WY on a snowmobile trip. I have a 2015 RAM 2500 6.7 tuned/deleted. Drove all the way down from ND truck was fine. Truck was fine yesterday morning got back to the truck after i rode sleds all day and the battery light was on and was showing low voltage. Drove 30mi to the hotel did what i could as far as testing. Thought the batteries were shot. I was able to drive another 40mi to an oreillys bought new batteries. Still isnt charging so i bought a alternator aldo. Left O'Reilly's and my alternator started whining and got very hot and started smoking. Changed the alternator in a Walmart parking lot started the truck a heard the new alternator make a whine noise and noticed it was getting hot also. Shut it down right away no smoke or any excessive heat b4 shut down. Then let it cool and started again no whine no crazy heat or smoke but the system is still not charging. I drove back to my hotel 40mi away. When i started going back to the hotel the voltage on the batteries was at 12V when i got to the hotel it was down to 11.8V. anyone have any ideas im kinda stuck in a bad situation i need help.