Background:
I've installed a new Orion XS 12-12/50 in my travel trailer. My tow vehicle is a 1 year old Ram 2500 with dual alternators, with a max output capacity of 380A (so there's no shortage of power). These alternators are controlled by the truck's ECU, so are for all intents and purposes are "smart alternators".
The Orion is fed via a 30' long 2 AWG run from the truck battery (the original wiring was done for a larger and less efficient DC-DC charger), and then reduced (and fused) to an 8" long 4 AWG feed to go to the Orion.
The problem:
Once the truck batteries are charged the voltage from the alternators drops to about 13.6v. I've calculated the voltage drop (50A at 13.6v for 30' one way) over my run to about .5v, which matches the ~13.15v that the Orion is reporting seeing on input. This causes the Orion to reduce charging from the max of 700w down to about 250-300w, because the "Shutdown voltage" setting defaults to 13.10v when you select "Smart Alternator" as the Alternator Type. I had to set the shutdown voltage all the way down at 12.8v to get about 500W out of it. I'm hesitant to go much lower, as the resting voltage of my truck batteries (as detected by the Orion) is 12.63v. There's way less voltage loss since the draw is effectively nil.
The trailer battery bank (412Ah of LiFePo4) was between 45 and 70% SoC during all of this testing.
What should I be setting my engine shutdown detection voltages and lock-out voltages at?