I have two of
these.
This is the
controller I use.
Battery bank is two 12 volt group 24.
When towing, I don't know how a person would tell how much power was coming from solar and how much was coming from tow vehicle, unless the tow vehicle provided no charging at all.
Length of time a person could expect for boodocking, depends on power usage, hours of sunlight, angle of sunlight, size (and condition) of battery bank, size and type of panels, type of controller, and wire size used to hook it up.
All my interior and exterior lights are LED, and my television is (low watt) 12 volt. No inverter to run any 120 volt appliances. We have boondocked for up to 5 days, with no noticeable drop in battery power. The solar panels kept up with a couple hours (daily) lights and television, and, all the parasitic draws from gas detector, refridgerator, etc.
I also have a panel on my TC. It is a single 135 watt with PWM controller.
Just out of curiosity, one sunny day, I disconnected the battery and connected the cables from the controller, directly to the converter. I was able to watch television and turn on a couple lights (also LED), with nothing but solar power.
