I've been fiddling around with charging procedures, since I don't have shore power where I store my RV. I'm now on a regimen of visiting my RV every 3 weeks to check the voltages of all batteries. I run the generator and turn on the Magnum charger panel inside to watch the charge setup. The chassis battery switch is on, and the house battery switch is on to run the generator.
On my last visit, for one hour, the charger delivered a 100 amp bulk charge. Then it dropped to absorb charging. I went for an errand and came back 3 hours later and it was on float.
Both sets of batteries were charging (they were reading a voltage from the charger and not an internal voltage). Indeed, I had a smart charger (which does bulk, absorb and float) connected to the chassis batteries while I did this -- I plugged it into the 110v port in the middle electrical bay that is designed for the engine block heater. The smart charger read a voltage, but no amps. I believe that is because the smart charger was seeing too high a voltage on the chassis batteries from the charging process from the generator -- I've checked the smart charger and it does charge batteries when there is no other charger hooked up.
This leads me to confident that the generator was charging both sets of batteries.
It is reasonable to expect the same to happen when on shore power.
Gordon Sick, Calgary
2015 Berkshire 34QS
2005 Acura EL (aka Honda Civic)