I am using the ac300 with 2 b300 batteries in my class C motorhome. I snaked a 30 amp cord from my rv cord storage to the compartment where the Ac300 is. So the motorhome is plugged into the ac300.
The AC300 has a 30 amp RV receptacle, but only supplies 25 amps (3000 watts), it will shut down if you try to use the full 30 amps. It will handle the 30 amp surge but not for long.
I also snaked a 20 amp extension cord through the same route as the 30 amp cord. At locations that provide electric I use the 20 amp extension cord, and plug into the 15 or 20 amp outlet and the ac300 is plugged into that cord. The ac300 will still provide the 25 amps if necessary (as long as there is a charge on the batteries), if I am using under 15 amps it will charge the batteries if necessary. The ac300 allows you to adjust the charging amperage from an ac outlet (1-30 amps).
I added 825 watts of solar on the roof. I will have to wait to see the solar production as it has been cloudy and I haven’t had a lot of sun since it is November.
I also added a dc to dc step up boost converter 12v - 48v, this is powered off the alternator and puts out 480 watts into the ac300.
My onboard Onan RV generator was used a few times to do partial charges. For the ac300 to take power from the generator I have to add a load to the generator first. I unplug the RV cord from the ac300, start my generator, then power up an electric heater (1000 watts), then I plug the ac300 into a n outlet. Without the load the ac300 sense an overvoltage fault, or the cycles are too high/low.
I will update this post when I do future trips.