Hi trickedyj,
My 2004 E-450 came directly from Ford with a solenoid for charging the house batteries. I somehow doubt that they would take a giant leap backwards to a diode based system.
Mine was fused at 60 amps, and because I have a medium size inverter (2500 watts) I blew the fuse more than once. I had a 2nd charging path added and switched over to 50 amp automatic circuit breakers.
The OEM Ford solenoid lasted less than a year before it had burned contacts. I moved up to a much heavier duty unit and all is well now.
Good luck with the new charging device that you have chosen. Please let us know if you can charge at a high rate. I have to limit the rate deliberately sometimes. I can do so because I added manual switching for the solenoids. My stock alternator only does 130 amps.
An additional consideration is the duty cycle of the existing alternator. It may not "like" you drawing 180 amps. On the other hand, you are going with a tiny battery bank, so perhaps that is not really much of an issue.
