I've been speaking with the folks at Navitas... what I did not realize, is that LFP batteries with integrated electronics cannot be hooked up in series, as there would be no way to equalize between batteries without external chargers/monitors. So I'll be getting one 24V battery for each FLU right soon, then another for each FLU in the future, and installing step-down converters for their trailer plugs. 12V or 24V, these batteries cost $4K per. Cheaper 6T LFP options exist, but can't be submerged. This is more than I intended to spend, but should also be the only batteries I ever need to buy for my FLUs, plus they'll integrate nicely with the master wind/solar plan for my homestead -- all my battery capacity will be vehicle-mounted. The GMC will have two NATO receptacles to extend the house-battery bank, if they're all more or less the same chemistry things become much simpler to integrate.
The GMC will also have two shore-power receptacles. One will be dedicated 120/240VAC @60Hz for the inverter-charger. The other will connect to a standalone charger (or bank of chargers) capable of automatically handling either 50 or 60Hz at any AC voltage from 85-265 for international compatibility. The GMC should be mission-capable for driving to Tierra Del Fuego, my research identified NINE different power standards between here & there. That Quattro unit also acts as my grid-tie inverter, but that capability will be limited to North America.
(If I can get it to Europe, it'll be mission-capable to invade Czechoslovakia despite only being the civvy version of the EM-50 Urban Assault Vehicle, honorary "Steel Soldier" status?)
The other cool thing about the Quattro are the three integrated programmable relays. Say my battery bank drops too low, the Quattro can be set up to start the Onan generator automatically. Just an amazing-looking product, on paper. LFP compatible, unlike most inverter-chargers; Victron's ahead of the adoption curve, there. The 2000W Newmar inverter-charger on the Dodge cost $2,750; the 5000W Quattro (thanks to a favorable currency exchange rate w/ the Euro atm) will run me $3,500. Also, it has two DC charger outputs, one high-amperage for the house bank, another 4A @24VDC out for the start battery. I'll need a step-down converter mounted next to the start battery, acting as its charger, because the "motor" part of my home will still be 12VDC. I'll update all the dash wiring and such to run off *that* instead of the + terminal of the start battery, such that the battery's only directly connected to the alternator and the starter motor. This is a boat-wiring practice I think makes a whole lotta sense for my land yacht!
From a North American standard 120/240/60Hz, 50-amp receptacle, every conceivable adapter & Y-cable is available to plug power into the standalone international charger. With my setup (not that I've quite pulled the trigger on it, I like ordering after-hours on Fridays as mentioned above), an adapter can be plugged into the receptacle wired to the Quattro. I'd be able to run all of my sub-contractors' power tools better than their own gas-powered generators, with my own 6KW Onan on standby if the sun isn't shining. But, with a FLU plugged into the GMC I'll probably be able to power two days of construction on the home I'm about to start building, just from the batteries.