First of all, laptops and cell phones really are not sensitive to voltage or frequency anymore, as they run on 19 volts DC or other DC voltage. Laser printers do not like modified sine wave power, but ink jets do not care if it is MSW or pure sine wave inverters.
Solar panels are great, and probably less expensive to run than buying a noisy and heavy generator. Weight wise, they have the generator hands down, same with noise.
The Champion or any inverter found at Costco or Home Depot, they are considered 'contractor grade generator' and while they will make great 60 Hz sine wave power, they are NOISY - like 85 - 100 Db. A car at idle should be around 60 Db, while a really noisy diesel truck might be around 90 Db while on the freeway.
I would recommend a pair of Honda 47 pound generators and they are easy to carry, make 2000 watts each for a few minutes, and 1,600 watts all day long. They can be paired together when you want to run the A/C unit.
I have heard that a 3000 watt Honda will not 'restart' a rooftop A/C on a hot day, once the compressor has been running, and then shuts off for say 8 minutes, the start up draw was more than this size generator could handle. I guess on a 85F day the amps will be a bit less, but still it is taxing the generator.
I have not heard concerns about a pair of Honda 2000's restarting a rooftop A/C unit.
Inverter generators have another advantage. They can have a very compact high voltage alternator, and run at a low RPM, so they are very quiet. The high voltage alternator can make say 3 amps at 600 volts, so it will not require more than about 1 pound of copper windings. Compared to a 4,000 watt generator making 120 volts it must have wire rated at 40 amps (for that surge start) and is about 20 pounds?.
The typical Onan RV generator runs at 3,600 RPM, is air cooled, so the cylinders that are the noisy part of a generator have a fan blowing air across that into the surrounding area. This makes them really noisy. A Honda 2000 can run at 900 RPM under minimal load, and is really quiet.
Also that Champion generator rated at 4,000 watts will be 90 - 120 pounds. Not something that I can pick up on a regular basis.
http://www.mayberrys.com/As for solar, you can buy a pair of 140 watt solar panels at $229 each from this place.
SunElec.com Add a charge controller rated at 30 amps for about $35, and you only need to add wire, mounts, and install it.
Your RV consumes 35 AH daily just to run the CO detector, propane leak detector and refrigerator. That is about what one of my 120 watt solar panels can make in 1 day.
Fred.