Originally Posted by JWA
Another guess is the majority of gas powered generators will be/are used in the AC form. Apart from marine applications DC-only generators would have limited use or appeal in the market segment serviced by gas powered equipment.
I agree that has been, and is still the case for the most part. Particularly for stationary power.
However, with large inverters becoming more affordable, to the point we can even run a camper's air conditioner off a 3000 to 5000 watt inverter, should it remain the normal design strategy? Why shouldn't the camper's inverter function in place of the inverter they incorporate in higher-end generators? The main reason for inverter generators is to allow the engine to run slower and thus more fuel efficient and quieter at partial loads. And we can't do that unless we have two inverters, or use DC charging, or else cycle generator on and off.
And as battery capacity also becomes lighter and less expensive, I think there is going to be a shift towards all-electric or mostly-electric RVs. If so, two scenarios jump out for auxiliary power. Either a very large capacity generator run off engine which can charge batteries in short order, or much smaller generator that can keep batteries charged over long periods of time -- much like has been discussed in fuel-cell thread.
I'd prefer the first, but not all vans have a second-generator option. And it would also add more cost due to needing more battery capacity to run AC overnight (like maybe 800 Amp-hours). On the other hand as long as batteries can supply starting surge, a small generator like the 55-Amp/800-watt unit linked above should be able to run a van AC without discharging batteries during night. Not suggesting that one -- would want a permanent generator tied to fuel tank.
Best of all the noise should be steady instead of generator surging every time AC compressor kicks in; which they may do a lot at night. That surging is what kept me from sleeping well with a 4 kW Onan I had. Steady background noise I can ignore easier.