When my Grand Cherokee Trailhawk was setup for flat towing I had them install a dedicated line to charge the Jeep's battery as well as power the InvisiBrake. I have done some trips with three day tows and have never had a dead battery. As a note, on overnight stops I do not disconnect the Jeep and have gone without starting on some overnighters. Again, never had an issue.
If they did not install a dedicated charge line might be something to consider having done or do it yourself. Power for the supplemental brake alone is not enough.
I am not sure about Patriot, but the Road Master InvisiBrake has a charging circuit that charges the TOAD's battery when the Motorhome's parking lights are on. My dedicated line is a supplement to the InvisiBrake's charging capability.
US Army (Ret)
2020 Entegra Accolade 37TS
2019 Jeep Grand Cherokee Trailhawk TOAD