One of my tests a couple years ago was to have the truck idle and clamp an inverter to the battery and power a Vector portable charger from the inverter to charge the trailer batteries. (in case my generator wouldn't work)
It all worked great but I had to hang the inverter outside from the engine compartment. By the battery (truck hood up) it was too hot from engine heat and the inverter alarmed off. I can't imagine running an inverter there with the hood down.
One item for Mena in Death Valley would be some way to keep the inverter in the remote vehicle cool enough --which would cost some AH from the bank on top of everything else.
