After a long day of splicing wires I finally have the entire setup installed. The Victron inverter/charger is both inverting and charging. Thanks everyone for the help in determining the right setup.
It was not without more hiccups today though. The batteries were again dropping to near zero voltage. I called Battle Born, who said the battery management system could be causing this, but they didn't know why. They suggested that the switch (Blue Sea Systems 350A on/off switch) could be bad. I completely removed the switch from the circuit, and that fixed the issue (at least for now). Maybe the switch was falsely tripping the BMS. I may experiment some more with different configurations for the switch.
