Charging APEX 300 if Charger 1 is connected to deep cycle RV batteries and not engine battery

I recently acquired the APEX 300 to power my RV. The unit will be placed inside the RV and my 30 amp plug will be plugged into the Apex 300 the entire time.

I need to charge the APEX 300 while driving and see that I can use the charger 1 to connect to my engine battery to charge it. My question is, can I connect the charger 1 to my deep cycle RV batteries (Not the engine battery) to charge the APEX 300 while driving? Currently the deep cycle batteries are charged when the engine is running or when onboard generator is on.

Second, if the charger one can be connected to the deep cycle batteries, will it also charge the APEX 300 when the generator is on?

Lastly, does the convertor in the RV need to be turned off to prevent the APEX 300 from charging the RV deep cycle batteries while the APEX 300 is on?

Thanks.

The charger 1 will charge the Apex as long as the input voltage to it is high enough. So yes, I would think it will charge from the deep cycles as long as they are being charged by either source. As far as the converter, I would think that would need to be off while the Apex is charging from the charger 1, or you would just have a loop going. If I am understanding correctly, that is how it should work. Also, if you get a 30 or 50 amp charging cable, you can charge from shore power when it is available.