I agree with Doug on this
Point of inverter connection is the batteries
The alternator simply keeps the voltage ? and hence the current a little higher
If you remove the battery from the circuit and attach the inverter directly to the cables with out the battery, it isn't going to work in almost all RVs
Certainly will not work in mine, going to need an alternator that can maintain 100+ amps at idle speed at full voltage at the connection point, with instant full amps, otherwise the inverter is going to fault and shut off