While most trailers, motorhomes, or RV owners install solar panels and battery systems to produce their electricity to run microwaves, refrigerators, and ACs, a decent-sized RV generator comes in handy during emergencies or when there are clouds and solar is not working correctly.
Even the most advanced and luxurious recreational vehicles need generators for emergencies and to run high-load appliances. However, if you have access to shore power, you should have more than enough power and shouldn’t necessarily need an inverter generator.
But before buying a generator, you might be wondering what size generator I need for RV? What size generator is big enough to run AC in my RV? How much power do I need to run my fridge? Can I power my entire with it?
Let’s find out some answers.
Let’s start by discussing wattage.
Generator size for an RV depends on the size of your vehicle, the number of appliances you want to run, and starting and running watts of those appliances.
A typical class C RV with 1 AC unit requires a 2500 to 3500-watt generator, a class A RV with two AC units requires a 6000 to 8000-watt generator, and a fifth wheel with two AC units requires a 5500 to 7000-watt generator.
Sure, it would be nice if there were a RV generator size calculator, but the truth is that every camper is different and with that the RV generators will be different as well.
Common generator sizes for different RVs.
These vehicle sizes can change based on your needs, but I have mentioned the most common types that most campers are using, including me.
| RV Type | AC Units | Generator Size in Watts |
| Class B Van | One | 2,500 to 3,500 |
| Class C RV | One | 6,000 to 8,000 |
| Class A RV | Two | 5,500 to 7,500 |
| Class A RV | Three | 10,000 to 12,000 |
| Fifth Wheel | Two | 5,500 to 7,500 |
How do you calculate wattage for RV Generator?
To calculate the wattage of your appliances, you need to multiply volts into amperes.
Watt = Volts x Amps
Most information on watts, volts, and amps is mentioned on the sticker inside your fridge. For example, for an old fridge, 115V and 6.5 amps are standard.
Volts x Amps
115 x 6.5 = 747.5
What wattage to typical appliances use in an RV?
Many appliances energy consumption is rated in BTU.
BTU stands for British Thermal Unit, which is the unit of energy used to measure power and heat output from different sources.
A BTU is the amount of heat required to raise one pound of water one degree Fahrenheit at sea level. This unit is often used when looking at efficiency ratings for appliances such as air conditioners or furnaces, or when calculating energy consumption in a building or home.
| Appliance | Running watts | Surge watts |
| RV AC Unit (10,000 BTU) | 1600 | 1000 |
| RV AC UNIT (15,000 BTU) | 3300 | 2000 |
| RV FRIDGE | 600 | 180 to 190 |
| Laptop | 250 | 250 |
| TV | 120 | 120 |
| Incandescent lights | 60 | 60 |
| A standard fridge | 1200 | 200 |
| Microwave oven | 1000 | 1000 |
| Coffee maker | 600 | 600 |
| AC (10,000) BTU | 4400 | 3000 |
| Electric blanket | 200 | 200 |
| Computer | 250 | 250 |
| Incandescent lights | 300 | 300 |
| Dishwasher | 1800 | 1300 |
| Electric Stove | 1000 | 1500 to 2000 |
| Blender | 800 | 300 |
| Curling Iron | 00 | 1500 |
Before diving into the topic, learn the difference between starting and running watts.
What is the difference between starting and running watts?
Starting, peak or surge watts means a brief surge in power required to start a motor-driven device. Running or rated watts refer to continuous power necessary to run a device.
Motor-driven devices such as a refrigerator require a brief surge in power to overcome inertia and start. Shortly after it is started, the refrigerator settles down to its original power requirement (running watts).
What is the difference between 30 amp and 50 amp in an RV?
A 50-amp plug can handle a bit more power than a 30-amp service. A 50 amp plug has four prongs, two 120V hot wires, a neutral wire, and a ground wire that supply two separate 50amp, 120V feeds. A 50-amp service can handle as high as 12,000 watts.
A 30-amp plug is used for lower load requirements. It has one 120V hot wire, a neutral wire, and a ground wire. It can handle as high as 3600 watts. Even with an adapter, a 30-amp service is limited to 3600 watts.
What size of generator do I need for a 30 amp and 50 amp RV?
A 30-amp connection with 120V equipment can handle up to 3600 watts. A 4000 – 4500-watt generator would be an ideal choice.
A 50-amp RV plug can handle up to 12000 watts with its two separate 50 amp feeds, but it doesn’t mean we have to lug around a huge 12000 to 15000-watt portable generator with us. That’s the size of a generator for fifth wheels that have multiple air conditioning units and plenty of appliances.
You’ll need plenty of power output to handle all of that.
A typical 6,000 to 7,500-watt portable inverter generator will do the job because we have to save space and reduce weight in our vehicle.
What size of generator is needed to power an RV’s AC unit?
| AC | Running watts | Starting watts | Generator |
| 7000 BTU | 600 | 1700 | 2000 watt |
| 10,000 BTU | 700 | 2000 | 2500 watt |
| 13,500 BTU | 1250 | 2700 | 3000 watt |
| 15,000 BTU | 1500 | 3500 | 4000 watt |
So, what is the best generator for an RV?
Based on my expertise and experience, I would suggest getting a Portable RV Generator with inverter technology over a conventional generator based on the following reasons:
- Inverter generators are significantly quieter.
- They provide clean power with minimum harmonic distortion. You can charge and power your sensitive appliances like laptops, drones, cellphones, coffee makers, etc.
- They are built to be highly compact and portable, so campers and RV users can lug them around without any problem.
- Inverter generators have excellent fuel efficiency.
- 90% of the inverter generators have eco-mode to increase fuel efficiency and reduce noise when not in use.
The best part of inverter generators is that they are very quiet, which is one of the essential things for camping. Make sure you look at the portable RV generator options to get the best one for your needs.
Some of the quietest portable generators for RV are:
- Honda EU2200i = 1800 running watts, 2200 starting watts.
- Westinghouse iGen 4500 = 3700 running watts, 4500 starting watts.
- Champion 4500W = 3500 running watts, 4500 starting watts.
- Generac GP3000i = 2300 running watts, 3000 starting watts.
Many of these RV generators we listed are small enough that you should have no problem coming up with generator storage ideas. Keep in mind, you’ll have to have a place to store it while it’s running and while you’re on the road.
