I've got a 2019 Touring with tow package and understand from other posts that this has a 190a alternator. I'm considering adding either a 40a or 20a DC to DC charger, either from Redarc, or Renogy to charge my RV Travel Trailer batteries while I'm towing. Could the vehicle support up to 40A load being sent to a trailer? Or, would it be best to stick with a 20A? Also, any suggestions on circuits to use, or if there is existing wiring that runs to the back I could tap into? I'd like to avoid running more wire if there is something I can leverage. Thanks for any tips.