I use a Curt Echo brake controller. When plugged into the vehicle 7 pin and trailer 7 pin, it works flawlessly.
In June I visited the Mother Ship. Cary, Craig, and Company installed a Lithium powered 12 volt system (Epoch Lithium battery) in my 2015 CampInn 560 and performed several other needed maintenance items.
I have changed my tow vehicle late in 2024 which had a four pin hookup. I jumpered the hookup with seven pin adapter without providing electrical connection for brakes or charging from the tow vehicle. My vehicle is rated to tow 5000 pounds, but I know my set up was illegal.
After returning from Wisconsin I installed a legitimate 7 pin on the tow vehicle. The Curt Echo trailer braking makes it street legal. Also, I can charge the 560 CampInn LiFEPO4 battery is possible from the tow vehicle, solar, and shore power.
In closing, at 78 I'm enjoying camping again. The Lithium conversion is the only way to go. The percentage of battery reserve is known with confidence. My unit 752 has over 50,000 miles, 333 nights, and travelled through 47 of the 48 contiguous states (missed Arkansas, somehow) and 9 Canadian provinces.