SO, you are now an “official” RV’er cuz you got one.
The answer to the generator need question is IT DEPENDS. It depends on what you have as an RV. It depends on how you want to use the RV. It depends on where you use the RV.
What do you have?
If you have a small tent camper, you do not need a 15,000 watt, 120/240 volt, industrial level, diesel generator that would feed the average size house or small business. You may be able to get away with just the on board battery in the camper and recharge it while running down the road using the tow vehicle’s charging system. If there is no air conditioner, you can get away with just charging the battery/s and running the water pump. This usually will take a 1000 watt unit to do any charging within a reasonable amount of time. You might need up to a 4000 watt unit depending on what equipment is installed in the tent camper and how you intend to use it. Most tent campers with air conditioners will need a 2800/3000 watt unit to take care of the a/c unit and leave enough to charge the camper battery/s and run the water pump. Almost all units in this size range are gasoline fueled. If possible, go with a 4 cycle engine rather than a 2 cycle. The 4 cycle is heavier but it is easier on fuel, maintenance and air pollution. If you plan on ‘boondocking’ buy a ‘quality’ unit. You don’t want to be let down on the first day in the desert.
Lets step up to a van camper and see what we need. Most vans have a roof mounted air conditioner. If it has a ‘scroll’ type compressor, you might get away with one of the heavier constructed 2800 watt units but it won’t leave much left over for other things. A 4000 watt unit will let you do more ‘electrical things’ than a smaller one. You can get some of those awning lights and vie with the neighbors for the most garish awning in the campground; not to mention those under body lighting systems and holiday lawn decorations with animated reindeer and blow up figures. I, myself have a picture of an 8 foot ‘Grinch’ on top of my 38 ft fifth wheel. (I am writing all four of my grandchildren out of the will over it – but – I digress.)
If you have a travel trailer (one you pull behind the vehicle) the choices get more complicated. The air conditioner is probably 13,500 or 15,000 btu or you have two of them. In addition, there are different sizes of ‘converters’ to run the 12 volt stuff and charge the battery/s. A little NOTE here; If you have never owned a generator before, figure the maximum size you want and then get one the next size larger. Once you get used to the convenience of a generator you, or the spouse, will have a tendency to keep adding things like TVs, big reading lamps, hair dryers, washing machines, etc.
If you have a fifth wheel camper (where somebody put the hitch in the middle of the pickup bed), you might be in the market for up to a 6500 or 7000 watt unit depending on what you ordered or purchased in your moment of ecstasy with the sales person at the dealership. Hopefully, you ordered it “generator ready” so the cabling and control wires are already installed and the floor is reinforced to take the weight of the unit.
Today’s motorhomes usually have a generator built in but, if not, the skies the limit. The 15,000 watt diesel unit mention in the first paragraph is probably the largest you would ever need. Most likely you would be happy with a 7500 or 10,000 watt diesel unit if the coach has a diesel engine. If the coach has a gasoline engine, the largest unit is usually a 7000 watt unit. The 15,000 watt unit lets you run the washer, dryer and water heater at the same time and still have the dishwasher and hot tub in operation. (They call it roughing it – smoothly.)
Generator Jim