Even if you could have a charger cord plugged in while driving,,,,
900 WATTS ??? 0.9kW ???
What will that do for the car. Try driving at an indicated 1kW.
And if you plan on stinking up and making noise at a camp ground (2 cycle),
900 watts is less than the Default L1 charge level of 8 Amps.
L1 @ 8A = 960 watts. L1 @ 12A = 1440 watts.
And as far as square wave, modified sine wave or 'pure sine' generators,,, I'm not experimenting. You first !!
Not sure what you are saying about a 24 V battery. You can plug in your camping 'deep cycle' battery to the car and charge it while you drive to the camp site.
But that doesn't make sense with an 80 mile BEV. I understand using a 12V battery while 'car camping'. A fan, a cpap and some lights makes for a good time!
There's an old thread here about someone with a 3500 watt generator in the back of a Spark EV....
Volts are getting very affordable if you really want a PHEV.