Using one dc/dc charger with several different trailers

[Ongeman]

I intend to mount this Orion XS 12/12/50 on or in my tow vehicle rather than at the battery locations as I have 3 trailers with coach batteries. Rather than buying 3 of these units $$$, one for each trailer. My question is this, is it safe to mount this inside the cab of the truck or does it generate too much heat for the interior? If mounted outside the interior, how much environmental protection does it require. (Under hood ok?) Also, it claims to monitor ambient temp when charging lead acid batteries. Is this the temp surrounding the charger or does it use a remote temp sensor? My lead acids could possibly be at a notably different temp than the location of the charger. I am using 4 awg wire and the longest run would be approx. 25 ft. Any input would be appreciated.