Choosing the right generator for your RV can be a bit confusing, but don’t worry, in this article we’ll look at the type of generator you’ll need based upon your RV’s size and the amount of electrical load your RV needs to supply to needed components that rely upon electricity. I’ll also share some of my thoughts on how best to maximize your RV generator during the times you will need to rely on it while boondocking or being off the grid.

Understanding wattage

To purchase the proper generator for your RV, you’ll need to understand the amount of wattage you will be suppling to its components. First, you should understand the theory of “watts law”, which is used when determining the amount of wattage needed to power your components by multiplying the amount amps needed with the amount of volts needed. In algebraic terms this is what would be known as P (wattage) = I (amps) x E (volts). In other words, the size of your generator is directly correlated with the amount of wattage your RV may draw at any given time.

For example, if your refrigerator requires 540 watts, you have a water heater that needs 1,350 watts and you need additional wattage for lighting, a TV, computer and recharging batteries for cell phones, cameras, laptop computers or any additional device or tool you have, then you’ll need to add on some additional wattage if you are thinking about buying a smaller size generator such as a 2,000 watt model.

Another thing to consider when choosing the proper generator is whether you will be using it to power your air conditioning units. To do this, you’ll need to understand what a British Thermal Unit (BTU) is and how it applies to what size generator you will need. A BTU is an international measure of energy that is the amount of heat needed to raise one pound of water by one-degree Fahrenheit. In the HVAC industry, BTU’s measure the quantity of heat an air conditioning unit can remove from a room per hour. Basically, the higher your BTU requirement, the more wattage your generator will need to produce.

Motorhome 5th Wheel and Camp Trailer Roof Top Air Conditioners Watts Required for start up Average wattage once running
7000 btu RV air conditioner 1,700 600
10,000 btu RV air conditioner 2,000 700
13,500 btu RV air conditioner 2,750 1,250
15,000 btu RV air conditioner 3,500 1,500
Household Items Running Wattage Requirements Additional Wattage Required for Starting
Coffee Maker 1,750 0
Dishwasher (Cool Dry) 700 1,400
Electric Frying Pan 1,300 0
Electric Range (8 Element) 2,100 0
Microwave Oven (625 Watts) 625 800
Refrigerator or Freezer 700 2,200
Automatic Washer 1,150 2,300
Elec. Clothes Dryer 5,750 1,800
Lights As indicated on Bulb 0
Radio 50 to 200 0
Color Television 300 0
Computers Running Wattage Requirements Additional Wattage Required for Starting
Desktop 600 to 800 0
Laptop 200 to 250 0
Monitor 200 to 250 0
Fax 600 to 800 0
Printer 400 to 600 0
Tools Running Wattage Requirements Additional Wattage Required for Starting
1hp Air Compressor 1,500 4,500
8″ Bench Grinder 1,400 2,500
1/2″ Hand Drill 600
High Pressure Washer 1 Horsepower 1,200 3,600
Circular Saw Heavy Duty 7-1/4 Inches 1,400 2,300
Electric Chainsaw 14″, 2 Horsepower 1,100 0
Table Saw – 10″ 1,800 4,500
3/8″ Drill, 4 amps 440 600
1/2″ Drill, 5.4 amps 600 900
Air Compressors Running Wattage Requirements Additional Wattage Required for Starting
1/2 Horsepower 975 1,600
1 Horsepower 1,600 4,500

In this graph, I have outlined what the wattage need is for most appliances or tools you may have or use as you travel. Obviously, unless you have a high dollar class A motorhome, you’re not going to be traveling with a dishwasher, full size freezer and electric dryer. However, my 5th wheel is equipped with a stackable washer and dryer, as well as a standard full-size refrigerator found in most sticks and bricks homes. So, it’s not unusual to find to find high wattage appliances in larger RVs although some are designed specifically for RV use and require less wattage as in the case of my clothes dryer which requires 2,750 watts to start and 1,250 watts to operate per hour.

This is also the case for my two rooftop air-conditioning units. You’ll notice in this graph that some tools or appliance require a higher amount of wattage when they start up, as opposed to when they are operating normally. This is because the motors or generators in some appliances are starting from a static or off position at the same time requiring more wattage.

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Champion Power Equipment 76533 4750/3800-Watt Dual...
  • Dual Fuel: Operate your 3800-watt portable generator right out of the box on either gasoline or...
  • Electric Start: Power up the 224cc Champion engine with the handy toggle switch, battery included

Personally, I recommend using a Champion 3,800-watt model that has a dual fuel supply option. This is a great added feature when dry camping because it allows you to power the unit with propane which is much safer to travel with than gasoline.

Another great feature of this generator is that it has an electric start and a manual pull start. It also has output outlets for 120v, 15-amp and 30-amp which give you a wide range of wattage and amperage to supply power to various sizes of RVs.

While this model is not large enough for me to operate both of my air conditioners, clothes dryer, microwave, TV and computer all at the same time, it can run what you want it to without overloading its supply. For that, you’ll need to consider the best way to reduce the power load from your generator.

Read about more of our recommendations in our guide on the best RV generators.

How do I reduce the wattage use in my RV?

In most RVs, it’s standard for the manufacturer to install your water heater and refrigerator to operate on electric and propane. Occasionally, you’ll find an RV that that has been specially ordered or modified because the original equipment failed. One of the best ways to save wattage is to have a water heater, and refrigerator that operate using propane gas. This greatly reduces the load from your generator’s hourly power draw, but more importantly its start-up load which puts the most stress on your generator.

You should also consider limiting your air conditioning. As I said before, I have two rooftop AC units that each require 2,750 watts to start and 1,250 watts to operate per hour. If both of them were to start at the same time, it would blow a breaker in my RV or one on the generator.

Avoid using multiple high wattage appliances at the same time. I have two air conditioners in my RV. One is in the bedroom area and the other is in the living kitchen area. I have never used both of them at the same time and neither should you. I also make sure to avoid using a coffee maker, microwave oven or any other appliance that requires more wattage than your generator can supply while the high draw appliances are powered.

In other words, always understand the amount of power you will need at any given time and make allowances for that. As always, my friends, stay healthy, stay safe, and I hope to see you out on the road soon.