Battery/generator needs for boondocking, solar not an option.

[SolarPoweredRV]

I am interested in converting over to Lithium (LiFePo4) battery but will need to change out my WFCO Converter/Power Panel. I currently have the WFCO 35 amp model WF-2735-PB converter and the WF-8735-PB Power Panle (I think based on the Data Sheet that came with the 22MLE. Any recommendation on a converter/power panel? I found one RV store - WFCO WF-8735-AD for about $230. Seems reasonable but I want to be able to to run 2 - 200ah lithium batteries down the road for boondocking.

The WFCO 8735 AD Converter you are considering is only 35 amps. If you install 200ah of Lithium batteries it will take a long time to charge your batteries if you ever need to charge them from a generator. I would recommend at least a 55 to 70 amp Lithium Converter, I also would recommend a Progressive Dynamics Converter over WFCO as I haven't heard any positive things about the WFCO AD Converters.

You might need to switch to a stand-alone Converter to get the higher amperage, you can just disconnect the old WFCO Converter and leave it in place (if you want to).

[SolarPoweredRV]

How much charging current can realistically be realized from the 7 pin 12V line? Adding a second alternator/charger would be limited by built in wiring. Just wondering if that is cost effective or run the second alternator and a separate wiring harness?

Not specifically questioned to your goals, just a general question.

When you have a battery bank that is 200 to 400 ah or more, a ~ 30 amp, 7-pin connection is not going to contribute an much in the way of charge your battery bank.

To realistically charge from your truck, you would need to install a DC to DC Converter in the truck along with heavy duty cables.

In my situation I originally disconnected the charging from the truck to the camper, however I recently decided to install a DC to DC Converter in the truck because there have been a few days where I felt we did not get enough Solar charging and I would have liked to have had a bit more charge to start our evening with (usually, I ran the A/C too much during our lunch stop).