Todays converters are nothing more than glorified battery chargers. In reality, that's all they do. Some may view them as a power supply, that supplies the 12v power when plugged in to grid, and that is true to a certain extent. But its easier to view them as strictly a battery charger that is replacing any 12v power that you are removing from the batteries. So in reality again, you could say you never removed power from the batteries as long as Grid power is connected.
Unlike yesteryears converters, there is no switching that takes place when using Grid power. The converter is just monitoring the 12v system voltage, and keeps supplying whats needed. And this is why the house batteries will always be charged by the converter.
The chassis battery should also be charged by the converter, but that would have costs the MFG a few $s more, so most would never go for that, altho, some do.
