hias9 said:
Are they any chargers available that can output something around 80-100VDC?
Yes of course many dozens, but largely designed for hard wired and stationary EV use, portability is a pretty unique requirement for such hefty power territory.
> Or lighter and more compact 42-58V 1500W-1800W chargers?
The Delta unit I just posted brags about power density, and Delta is a global leader in telecom / industrial class power. See the data sheet for the units they use in order to do comparisons apples to apples.
> Cannot draw more than 16amps at 230VAC, so two 3000W chargers would not make sense.
My strategy is to use multiple units of 1000-1200W each, to give flexibility on inputs, ability to tap into multiple separate AC circuits,
then concurrently parallel the DC outputs together to get up to 3kW (when possible) from regular household or older campground circuits, or ones with other loads running. When / where such big feeds aren't available, make do with fewer units and amps, but keep voltage output within spec.
I need "global / universal" AC compatibility too 115/230V 50/60hz, which narrows choices as well.
Another approach, if you don't need to service loads while charging, is to create quick-disconnects between packs and charge each separately at lower voltage, since 12V and 24V rack-server PSUs from IBM, HP and Dell put out very clean power and are very robust, reliable and available very very cheaply.
Some are even quiet and relatively compact (energy dense).
Don't look at everything you need coming in one unit, it may be out there but likely not a bargain. Paralleling multiple units to me makes more sense, both for flexibility and redundancy if the use case is a mission critical one. Of course need to research and test for Common Reference / Return issues, not to mention true Earth, usually lacking in a mobile / Floating context.
Finally, you can put DC-DC chargers between your high-amps but less-adjustable 48+V PSUs and your battery packs with various voltage needs.
iCharger 4010-Duo and FMA Powerlab-8 come to mind.
As do Victron & Sterling's BB series, more robust / reliable but less flexible.