To address the statement about the battery minders getting hot. I went out and checked mine (only 3 running at this time) and the Deltran ones that I have are basically running at the ambient temperature of were they are at. They are showing a full charge. This prompted me to get my rear in gear and get the new MH set up. I had to do some fancy work on the Sprinter chassis to get it all hooked up but it is done and charging as we speak. Glad I got that done instead of waiting till it was cold out and then have to fumble around tearing the front apart t get it done. The chassis battery is in a compartment under the drivers seat so you have to take some trim off and the pull the floor out covering out and then take a panel off and there is this big long battery.
Anyway it is done, thanks to the OP as it got me going.