Running trailer from tow vehicle inverter

rbpru wrote:
You can also do what I did to get an extra day out of my battery. I pulled the truck up to the TT and ran a set of jumper cables to the TT battery and charged it for 20 minutes off the truck.

You do what you have to do and while this is better than doing nothing the net gain will be minimal. It's the raison d'être for DC > DC chargers to even exist. ;)