Hello Rob, here’s my setup which could be used as a point of reference:
Tow vehicle: 2022 Jeep Wrangler 3.0 diesel
Trailer: 5’x10’ offroad
Trailer batteries: 2 x Relion LifePo4 100hr LT
Victron B2B charger: Orion XS
Tow vehicle to rear anderson plug: 6 awg with post fuse at 60 amps (approx 12’ run)
Trailer to Orion XS: 6 awg (approx 12’ run)
Orion XS to Batteries: 6 awg (approx 4’ run)
Charge profile: bulk=14.6, absortion=14.6, float=13.2
The Relion batteries have a BMS with low/high temp management, so settings for those are unnecessary in the Orion XS.
Because my jeep has a Euro 6 power plant, engine off detection settings were difficult to determine because the smart alternator varied wildly during operation. Ultimately I had to change the minimum charge voltage in the jeep system to 14V to get proper engine off detection.
The above system has worked extremely well for me. Again, this post is intended as a reference.