Battery Charge whilst Towing

I have a 13 foot 2022 Scamp with electric only Refrigerator.

My tow vehicle is putting out around 12.4 volts which is not sufficient to fully charge the AGM (?) battery I have. (This is the standard battery upgrade from SCAMP).

I had a friend turn me on to the idea of a special battery charger that sits between the tow vehicle and the scamp battery. It takes power from the tow and up-voltages it to a voltage and charge profile that is correct for the kind of battery that you have.

To complicate things a little bit, I wanted to be able to charge with Solar and/or Tow; sometimes both at the same time (perhaps). I found a device from Renogy that says it will do this.

The final install. The top is the right camper wall.

I got it and installed it in the well below the forward closet where the break-out box for the tow cable resides. It appears to work great. Some specific Issues:

1) The 12V from my tow vehicle is direct from the battery. It is ALWAYS on. I don't want my fridge discharging my car battery if I have it parked at a hotel or something overnight (and I forget to disconnect the tow power cable). The Renogy solves this by requiring a "Ignition" connection. I hooked up this low current line to my running lights line on the tow cable breakout box. That worked great. (I tow the trailer with running lights on because that also powers the look behind camera).

2) The Renolgy box I got is very large. It is also way over-powered for the little 13 foot scamp electrical. This is not bad, per-se, but means it is more expensive and harder to hide that it needs to be. So.... if someone finds another solution....

3) I drilled a hole out the bottom of the floor and put in a cable connection so I can plug in a portable solar panel that goes right to the Renogy and provides additional power. On a sunny day I can run the fridge and charge the battery for the night, no problem.

4) Don't trust the wire connection ordering on the Tow Cable Break-out box. It is not standard. I advise you to confirm the connection of each wire with a ohm-meter or something.

I am not claiming this is the end all, but I have used this hook-up for a couple of trips and it is working just fine.