Residential refers require 110 volts AC. Not 12 volts DC and or propane.
To get that 110 volts you need a long enough extension cord to drive hundreds of miles.
Or you can run the onboard generator which eliminates the extension cord
Those are two of the 110 volt supply sources. If you are sitting with the engine of,f then your batteries 12 volts that is, can be used to convert/invert that DC voltage to AC voltage. At the same time it steps up the voltage to 110/120 whatever pops your corn term you like to use.
An inverter basically turns the DC on and off extremely rapidly thus creating a pulsing DC current and voltage. That quick change causes magnetic things to happen in transformers and they get excited and carry that excitement to the outlets.
The AC voltage in your house is like drinking pure water. The AC from an inverter is like drinking water that might be a bit cloudy. Drinkable but not the most pleasant. It may be good for cooking but just not palatable to drink.
So the term Pure Sine Wave inverter comes into play when discussing the magic boxes that take battery DC voltage and convert it to AC voltage.
Many appliances do not like the cloudy water and will get sick drinking it. They can let their internally stored smoke out and you need a new one thereafter.
The limits of this inverting systems is the size/capacity/and state of health of the buckets of marbles in the battery compartment. There are two banks of buckets. One to run the house side and one to run the normal engine/ car type functions.
The house batteries can only hold so many marbles before they do not like to play with the inverter and the inverter says go away and shut themselves off.
The more house batteries the more marbles you have to play with. Simple as that.
Before you say I have lost my marbles, hang in there a bit.
You need a way to get those marbles back into the batteries you lost playing keepsies with the inverter.
To refill the buckets you can use that same inverter/converter in many cases. That darn thing is pretty smart and has a split personality. Maybe because of all the lost marbles.
The converter portion of the crazy device can sense when you connect to shoreline. That is you have the fuel station plugged into the tank. That electron fuel comes in at 110 volts and feeds the converter. Watch carefully as I use the term converter and not inverter. They are confusing and often are used interchangeably.
The converter senses the 110 supply line and begins to produce marbles for the battery buckets. This production can fill the house batteries as well as the engine batteries depending on the design and state of repair of those systems.
The converter can be matched to various types of batteries and can often be adjusted to fill fast or slower depending on the fuel pump. (shoreline).
Ok, so the extension cord is just too heavy to haul and you drive off. There is that engine driven alternator just like any other vehicle you drive. It is like having an onboard fuel station, except it does NOT provide that pure 110 volts like the fuel station/shoreline does.
The alternator provides DC voltage. Ok, now all you techies out there do not admonish me for not being precise here. The DC supply from the alternator is just marbles the batteries like and you can fill those battery banks running down the road. Again, depending on the build of the chassis and status of it.
I have not mentioned solar but that is DC 12 volt option to fill those buckets as well.
Of course you can run the generator and the alternator running down the road and have lots of refill options.
To run a residential refer it takes 110 volts. How you get that has been explained. They like to use a fair amount so getting in flight refueling is a good thing. That is, the generator or alternator providing the refill.
As any good ice chest has insulation and can go hours more if left unopened you can drive for many hours without the refer turned on. They cool quickly and take the freezer down to subartic temps that requires a jackhammer to scoop ice cream.
The problem comes when you park without any refueling station available. You are now relying on just the batteries/buckets of electrons. You have a limited supply so how often you open the refer door (sounds familiar), how hot it is outside etc, will gauge how long it can keep things cozy until the batteries get too low to participate in the game.
If you boondock, then you either need to run a generator (a small one is often handy), to refill the batteries. A couple of hours in the am and pm for sure. You need to convert as many lights as possible to leds. You absolutely must become and energy manager.
Of course you can add all the batteries you can find room for but then you have to run the fuel station longer to fill them.
I used to use a Honda 1000 to keep my batteries up on our 42 footer. Turning the charger down kept the Honda happy and not overloaded. Quite and efficient.
If you do not boondock, and we do not any longer then you actually don't need as many batteries. I reduced my house batteries in half over a year ago.
I do NOT even have my refer on the inverter circuit, meaning I must run the generator for it to function or move the plug to the inverter in an emergency.
However, my inverter puts out the cloudy water type AC. It is not a pure sine wave model and could let the smoke out of my precious ice cream concrete maker. (I have to nuke the ice cream to scoop it)..
Inverters come in all sizes and shapes. They are only limited by your imagination and budget. Yes you could even run air conditioners but you would drain those battery buckets in just minutes for sure.
Thanks for listening.