Hitting the open road in your travel trailer offers unparalleled freedom, but that sense of adventure often comes with the need for a reliable power source. Whether you're boondocking in the wilderness or simply want to run a few appliances off-grid, a generator is an essential piece of equipment. However, choosing the right one can be a daunting task. The question "what size generator for travel trailer?" is one of the most common and important decisions an RVer will make.

what-size-generator-for-travel-trailer
Picture: campgroundviews.com

The answer isn't a one-size-fits-all solution. It depends on a variety of factors, from the size of your rig to the specific appliances you plan to run. This comprehensive guide will walk you through the key considerations, helping you calculate your power needs and choose a generator that's perfect for your unique travel style.

Understanding the Basics: Watts, Amps, and Volts

Before you can size a generator, you need to understand the fundamental electrical terms. Don't worry, this isn't a college physics class—just the basics you need to know to make an informed decision.

  • Watts (W): This is the most important number for you to know. Watts measure the total power that an appliance consumes. Think of it as the total "work" being done. When you look at a generator's specifications, you'll see two wattage ratings: running watts and starting watts.
  • Running Watts: This is the continuous power an appliance needs to operate.
  • Starting Watts (or Surge Watts): Many appliances, especially those with electric motors like air conditioners, refrigerators, and microwaves, require a brief but significant surge of power to start up. This starting wattage is always higher than the running wattage. Your generator must be able to handle this peak demand.
  • Amps (A): Amps measure the flow of electrical current. Most travel trailers and RVs in the U.S. are wired for either a 30-amp or 50-amp electrical service. This rating tells you the maximum amount of current your RV's system can handle.
  • Volts (V): Volts measure the pressure of the electrical current. In the United States, most travel trailer appliances operate on 120-volt AC power, just like in your home.

The relationship between these terms is simple: Watts = Amps × Volts. Knowing this formula can help you calculate your total power needs if your appliances are rated in amps instead of watts. For a 30-amp RV, the maximum wattage is 30A×120V=3600W. For a 50-amp RV, it's a bit more complex. A 50-amp service actually has two 50-amp legs, giving you 50A×120V×2=12,000W of total power available.

The Most Important Step: Calculating Your Travel Trailer's Power Needs

This is where the real work begins, but it's the most critical step to ensure you don't buy a generator that's too small or, conversely, waste money on one that's too large.

Step 1: Make a List of Your Appliances. List every appliance and device you plan to use with the generator. This includes everything from the big-ticket items like your air conditioner and microwave to smaller electronics like your coffee maker, TV, and laptop.

Step 2: Find the Running and Starting Wattage for Each Item. This information is usually found on a sticker or data plate on the appliance itself, or in the owner's manual. If you can't find it, you can use average wattage charts (like the one below) as a good estimate. Remember to note both the running and starting watts for each item.

The Most Important Step: Calculating Your Travel Trailer's Power NeedsThe Most Important Step: Calculating Your Travel Trailer's Power Needs

Step 3: Calculate Your Total Wattage. First, determine the maximum surge you'll need. Identify the appliance with the highest starting wattage. This is your most demanding piece of equipment. Then, add the running watts of all other appliances you plan to run at the same time.

Formula: (Highest Starting Watts) + (Sum of all other appliances' Running Watts) = Total Starting Wattage Required

Example Scenario: Let's say you want to run your 13,500 BTU air conditioner, the RV refrigerator, and a few lights.

  • Highest Starting Watts: Air Conditioner = 3,000 W
  • Other Running Watts: RV Refrigerator (180 W) + Lights (50 W) = 230 W
  • Total Starting Wattage Required: 3,000 W + 230 W = 3,230 W

Your generator will need a starting wattage capacity of at least 3,230 watts.

Now, calculate your total running wattage. Add the running watts of all the items you will use simultaneously.

  • Total Running Wattage Required: Air Conditioner (1,500 W) + Refrigerator (180 W) + Lights (50 W) = 1,730 W

Your generator will need a running wattage capacity of at least 1,730 watts.

Based on this calculation, a generator with a running wattage of around 2,000 watts and a starting wattage of 3,500 watts would be a good fit.

Pro-Tip: The 80% Rule. Always choose a generator that has at least 20% more capacity than your calculated needs. Continuously running a generator at its maximum capacity can shorten its lifespan and increase the risk of damage. For our example, a generator with a running wattage of around 2,000 watts would be perfect, giving you a comfortable buffer.

Popular Generator Sizes for Travel Trailers

Based on the size of your travel trailer and your typical power usage, here’s a breakdown of the most common generator sizes and what they can power.

  • 1,000-2,500 Watt Generators:

    1. Best for: Small travel trailers, pop-up campers, and minimalist campers who only need to run essentials.
    2. What they can power: Lights, a laptop, phone chargers, a small fan, and a coffee maker. They are generally not powerful enough to start and run an air conditioner.
    3. Ideal for: Boondocking or overnight camping where power needs are low.

  • 3,000-4,000 Watt Generators:

    1. Best for: Medium-sized travel trailers (20-30 ft) with a 30-amp electrical system.
    2. What they can power: This is the sweet spot for many RVers. A generator in this range can typically run a 13,500 BTU air conditioner and a few other small appliances simultaneously, like a TV, refrigerator, and lights.
    3. Ideal for: Campers who want to be able to use their air conditioner on hot days and power most of their essential appliances.

  • 5,000-7,500 Watt Generators:

    1. Best for: Larger travel trailers and fifth wheels with 30-amp or 50-amp service.
    2. What they can power: These generators can handle a much larger load. They can easily power a 15,000 BTU air conditioner, a microwave, an electric skillet, and other heavy-duty appliances at the same time.
    3. Ideal for: RVers who want to run multiple high-wattage appliances and have a true "home away from home" experience.

  • 8,000+ Watt Generators:

    1. Best for: The largest travel trailers, fifth wheels, and toy haulers with 50-amp service, especially those with multiple air conditioning units.
    2. What they can power: A generator of this size can handle almost anything you throw at it, including two A/C units, a washer/dryer, and a residential-sized refrigerator.
    3. Ideal for: Full-time RVers or those with luxury rigs that require a significant amount of power.

Other Factors to Consider When Buying a Generator

Sizing is just one part of the equation. To make the best choice, also consider these factors:

1. Inverter vs. Conventional Generators

This is a critical distinction.

  • Conventional Generators: These are the traditional, open-frame generators you often see on job sites. They are typically louder, produce "dirty" power (unstable voltage), and are best for powering tools or appliances that aren't sensitive to voltage fluctuations.
  • Inverter Generators: These are a more modern, advanced option for RVers. They are significantly quieter, produce "clean" sine wave power that is safe for sensitive electronics (laptops, TVs, smartphones), and are more fuel-efficient because they can adjust engine speed to match the load. While they often have a higher price tag, the benefits of lower noise and clean power make them the preferred choice for most campers.

2. Fuel Type

Generators run on a variety of fuels.

  • Gasoline: The most common and widely available fuel type.
  • Propane: Cleaner-burning than gasoline, it's often more convenient for RVers who already use propane for other appliances. Many generators are "dual fuel," allowing you to switch between gasoline and propane.
  • Diesel: Typically used for larger, more powerful generators found in big motorhomes. Diesel engines are known for their durability and fuel efficiency.

3. Noise Level

Generator noise is a major concern, especially in campgrounds and at boondocking sites. Noise is measured in decibels (dBA). Inverter generators are the clear winner here, often operating in the 50-60 dBA range, which is comparable to a quiet conversation. Conventional generators can easily exceed 70 dBA, which can be disruptive to you and your neighbors.

4. Portability and Weight

Consider how you will transport and store the generator. A 2,000-watt inverter generator might weigh less than 50 pounds and can be carried by one person. A 5,000-watt conventional generator can weigh well over 100 pounds and may require a hoist or two people to move.

Final Thoughts: The Right Generator for Your Travel Trailer

Choosing the right size generator for your travel trailer is a crucial step in ensuring a comfortable and worry-free camping experience. Start by honestly assessing your power needs, listing all your appliances, and calculating both your running and starting wattage requirements. Once you have those numbers, you can confidently narrow down your options.

For most small to medium-sized travel trailers, a quiet, portable inverter generator in the 2,000 to 4,000-watt range will provide more than enough power to keep your adventures running smoothly. By doing your homework and choosing the right generator, you can enjoy the freedom of the open road without ever having to sacrifice the comforts of home.