Sizing Your RV Generator to Match Your Specific Power Needs

There's nothing quite like the freedom of the open road in your RV, but that freedom can quickly turn into frustration if you're constantly tripping breakers or, worse, completely powerless. The secret to uninterrupted adventures? A perfectly sized RV generator. It's not just about having a generator; it's about having the right one that meets your specific power demands without excess, ensuring comfort, convenience, and peace of mind wherever you roam. Getting this right is crucial for a comfortable camping experience.

At a Glance: Key Takeaways for Sizing Your RV Generator

• Calculate Your Needs: List all appliances you might run simultaneously, noting both their running watts and crucial starting (surge) watts.
• Prioritize A/C: Your air conditioner is likely your biggest power hog, especially its starting watts. Size your generator primarily around this.
• Inverter vs. Conventional: Inverter generators offer clean, stable power for sensitive electronics and are generally quieter and more fuel-efficient.
• Consider Your Lifestyle: A small portable might suffice for basic needs, while larger RVs or full-timers will need more robust built-in or large portable units.
• Factor in the Future: It's often wise to choose a generator with a little extra wattage for future upgrades or unexpected power demands.
• Safety First: Always operate your generator outdoors, away from your RV, and with a carbon monoxide detector on hand.

Unpacking Your RV's Power Demands: Running vs. Starting Watts

Before you can pick the perfect generator, you need to understand what your RV needs to power. This isn't just about how many lights you want on; it's about the very specific electrical characteristics of your appliances. The two most important numbers you'll encounter are "running watts" and "starting watts."

• Running Watts (or Rated Watts): This is the continuous power an appliance draws once it's up and operating steadily. Think of it as the electricity needed to keep the lights on, the fridge cold, or the TV playing. Most appliances list their running watts right on their label or in their manual.
• Starting Watts (or Surge Watts): This is the brief, extra burst of power an appliance needs to kick on, especially those with electric motors. Your RV air conditioner, refrigerator, and microwave are prime examples. This surge can be two, three, or even four times the running wattage, lasting only a few seconds, but it's critical your generator can handle it. If your generator can't provide this initial surge, the appliance won't start, or it could overload the generator.
  You'll need to account for both when sizing your generator. Your generator's "peak" or "surge" wattage capacity must meet the highest starting watt requirement of any single appliance, while its "running" or "continuous" wattage must be able to handle the sum of all appliances you plan to operate simultaneously.

What's Eating Your Power? Common RV Appliance Demands

To help you get started, here's a look at the typical power requirements for common RV appliances. Remember, these are averages, and your specific unit might vary. Always check the labels on your appliances for the most accurate information.

Types of RV Generators: Finding Your Match

RV generators come in several forms, each suited for different needs and lifestyles. Understanding the distinctions will guide you toward the right fit.

1. Small Portable Generators (2,000-3,000W)

These compact units are perfect for minimalists, weekend warriors, or those who mostly rely on shore power but want a backup for basic needs.

• Ideal for: Charging devices, running lights, a small TV, and perhaps a coffee maker. They're typically not powerful enough for an RV air conditioner unless it's a very small unit or you're using a soft start kit.
• Pros: Lightweight, easy to store, relatively inexpensive, often quiet (if inverter type).
• Cons: Limited power output, won't run demanding appliances.

2. Medium Inverter Generators (3,000-4,000W)

Often the sweet spot for many RVers, these generators offer a good balance of power and portability.

• Ideal for: Running a 13,500 BTU RV air conditioner (often the largest single power draw), a microwave, and several smaller appliances simultaneously.
• Pros: Excellent fuel efficiency, quiet operation (a major plus in campgrounds), clean power for sensitive electronics, good power-to-weight ratio.
• Cons: More expensive than conventional generators of similar wattage, heavier than small portables.

3. Large Portable Generators (4,000-5,500W)

When you need serious power on the go, a large portable can often bridge the gap between medium portables and built-in units.

• Ideal for: Larger RVs, full-time living, or boondockers who want to run a 15,000 BTU A/C, multiple systems, and high-wattage appliances like an electric water heater or hair dryer.
• Pros: Substantial power output, still portable (though often with wheels), versatile.
• Cons: Can be quite heavy and bulky, may be noisier than inverter models, less fuel-efficient.

4. Built-in RV Generators (2,800-7,000W)

These are integrated directly into your RV's chassis, wired into its electrical system, and often plumbed into the RV's main fuel tank.

• Ideal for: Large motorhomes, fifth wheels, or anyone seeking the ultimate convenience and full-home power experience. They can power entire RV systems.
• Pros: Seamless operation (often with an auto-start feature), integrated fuel system, weather-protected, minimal setup required, usually quieter than large conventional portables due to specialized enclosures.
• Cons: Highest initial cost, permanent fixture (not versatile for other uses), maintenance can be more involved.

The Wattage Math: Your Step-by-Step Sizing Guide

Ready to crunch some numbers? Here's how to calculate your minimum generator needs.

Step 1: List Your "Must-Have" Appliances

Think about the appliances you absolutely need to run simultaneously. This is where your RV lifestyle comes into play. Are you a minimalist who just needs to charge your phone and brew coffee? Or do you want to run the A/C, microwave, and watch TV at the same time?

Step 2: Sum the Running Watts

Add up the running watts for all the appliances you identified in Step 1. This gives you your total continuous power requirement.

Step 3: Identify the Highest Starting Wattage

Look at your list of appliances and find the single appliance with the highest starting wattage. Typically, this will be your air conditioner.

Step 4: Calculate Your Minimum Generator Size

Your generator's continuous running watts must be greater than or equal to the sum from Step 2. Crucially, its maximum surge wattage must be greater than or equal to the highest starting wattage from Step 3.
Here's the formula:

• Required Running Watts: Sum of all running watts for appliances you'll use simultaneously.
• Required Starting Watts: The highest starting wattage of any single appliance on your list.
  Example Scenario:
  Let's say you want to run:
• 13,500 BTU RV Air Conditioner: 1,500 Running W / 3,500 Starting W
• RV Refrigerator: 500 Running W / 1,000 Starting W
• Microwave Oven: 1,000 Running W / 1,000 Starting W
• TV/Entertainment: 300 Running W
• Laptop Charging: 100 Running W
  Calculation:

1. Total Running Watts: 1500 (A/C) + 500 (Fridge) + 1000 (Microwave) + 300 (TV) + 100 (Laptop) = 3,400 Running Watts
2. Highest Starting Watts: The A/C is 3,500W. The fridge is 1,000W. The microwave is 1,000W. The highest is 3,500 Starting Watts.
   Result: You would need a generator capable of delivering at least 3,400 continuous running watts and at least 3,500 peak (starting) watts. A 3,500-4,000 watt inverter generator would likely fit this bill perfectly. It’s always smart to have a little buffer, so aiming for a generator slightly above your calculated needs is a good practice.
   Important Note: You don't add all starting watts together because those surges happen sequentially, not simultaneously. Your generator just needs to handle the single largest surge when it happens.

Beyond Watts: Key Features to Consider

Wattage is just one piece of the puzzle. Several other features significantly impact your experience.

1. Inverter vs. Conventional Generators

This is one of the most critical choices you'll make.

• Conventional Generators:
• How they work: Run at a constant engine speed (typically 3600 RPM) to produce power.
• Pros: Generally more powerful, less expensive upfront for a given wattage.
• Cons: Noisy, less fuel-efficient, produce "dirty" power (less stable sine wave) which can be harmful to sensitive electronics like laptops, smartphones, and some RV control boards.
• Inverter Generators:
• How they work: Use an advanced alternator and a special inverter circuit to produce AC power. The engine speed adjusts based on demand, making them very efficient.
• Pros: Produce "clean" sine wave power, ideal for sensitive electronics, much quieter, more fuel-efficient, lighter and more compact for their power output.
• Cons: More expensive initially.
• Verdict: For RVers, especially those with modern electronics, an inverter generator is almost always the superior choice.

2. Noise Levels (dB)

Nobody wants to be that RVer with the roaring generator. Noise levels are measured in decibels (dB), and lower numbers mean quieter operation.

• Consider this: Many campgrounds have noise restrictions, often around 60-65 dB at 20 feet. National Parks are even stricter.
• Typical Ranges:
• Quiet conversation: 60 dB
• Inverter generators: 50-65 dB (at 25% load, 23 feet)
• Conventional generators: 65-80+ dB (at 25% load, 23 feet)
• Why it matters: A quieter generator makes for a more pleasant camping experience for you and your neighbors. Inverter generators excel here.

3. Portability Features

If you're opting for a portable unit, consider how easy it will be to move and store.

• Weight: Some large portables can weigh over 200 lbs.
• Size: Will it fit in your RV's storage bay or truck bed?
• Wheels and Handles: Essential for anything over 70-80 lbs.
• Design: Some are designed for easy stacking or compact storage.

4. Fuel Type: Gasoline, Propane, or Dual Fuel?

• Gasoline: Most common, widely available.
• Propane: Cleaner burning, longer storage life, often available at campgrounds. Produces slightly less power than gasoline for the same engine size.
• Dual Fuel: Offers the best of both worlds, letting you switch between gasoline and propane. This gives you flexibility in fuel availability and potentially longer runtimes. While dual-fuel generators have a higher initial cost and slightly more maintenance, the benefits of fuel flexibility and propane's cleaner burn often outweigh the drawbacks for many RVers.

5. Starting Mechanisms

• Recoil Start: Manual pull-cord, simple and reliable.
• Electric Start: Push-button start, requires a small battery, very convenient.
• Remote Start: Start/stop from a distance, ideal for built-in units or when you don't want to go outside.

6. Outlets and Power Output

Ensure the generator has the right outlets (e.g., 30A RV receptacle, 120V standard outlets) to connect to your RV and other devices. Some larger units also offer 240V outlets, though less common for RV primary use.

Keeping it Running: RV Generator Maintenance Essentials

A generator is an investment that needs care. Regular maintenance ensures reliability and extends its lifespan.

Before Every Trip

• Check Oil Levels: Just like your car, low oil can cause serious damage. Top off if needed.
• Inspect Air Filter: A dirty air filter restricts airflow, reducing performance and increasing fuel consumption. Clean or replace if necessary.
• Test Run the Generator: Don't wait until you're off-grid to find out it won't start. Run it for 15-30 minutes with a load to keep components lubricated and clear out old fuel.
• Inspect Fuel System: Look for leaks or kinks in fuel lines, especially if it's been stored for a while.

Every 3 Months (or after extended use)

• Change Oil: Even with low usage, oil degrades. Follow your manufacturer's recommendations for oil type and change intervals.
• Service Air Filter: This might involve cleaning or replacing, depending on the filter type and conditions.
• Check Spark Plug: Clean or replace the spark plug to ensure efficient combustion.
  Maintenance Tip: Always refer to your generator's owner's manual for specific maintenance schedules and procedures. Different models and manufacturers will have slightly different requirements. For a broader overview, you might find Your guide to RV generators helpful as well.

Safety First: Operating Your RV Generator Responsibly

Generator safety is paramount. Carbon monoxide (CO) poisoning is a silent killer, and improper operation can lead to fires or electrical hazards.

Operational Safety

• Placement is Key: Always operate your generator outdoors, at least 20 feet away from your RV and any other enclosed structures. Ensure exhaust fumes are directed away from windows, doors, and vents.
• Stable Ground: Place the generator on a level, stable surface to prevent tipping.
• Weather Protection: While some generators are weather-resistant, avoid operating them in heavy rain or snow unless they are specifically designed for it and properly sheltered with an open-air cover. Never operate in an enclosed space.
• Proper Fueling: Always shut off the generator and allow it to cool before refueling. Spilled fuel on a hot engine is a fire hazard.

Carbon Monoxide (CO) Safety

• CO Detector is Non-Negotiable: Ensure your RV has a working carbon monoxide detector and test it regularly. This is your most important defense against CO poisoning.
• Wind Direction: Be mindful of wind direction, which can blow exhaust fumes into your RV or a neighbor's.
• Never Indoors: Never operate a generator inside an RV, garage, tent, or any other enclosed or partially enclosed space. Even with windows open, CO can build to dangerous levels.
• Symptoms: Familiarize yourself and your family with the symptoms of CO poisoning (headache, dizziness, nausea, weakness). If suspected, get fresh air immediately and seek medical attention.

Burning Questions Answered: RV Generator FAQs

Let's tackle some common questions and clear up misconceptions about RV generators.

Can I run my RV A/C with a portable generator?

Yes, but it depends on the generator's wattage. Most RV A/C units (13,500 BTU or 15,000 BTU) require substantial starting watts (3,000-4,000W). A medium to large inverter generator (3,000W+ continuous, with sufficient surge) is usually needed. Altitude can also affect generator performance, potentially reducing its effective output, so consider this for high-elevation camping. Using a soft start kit on your A/C can significantly reduce its starting wattage requirement, allowing smaller generators to power it.

What's the difference between a built-in and a portable RV generator?

How long will a generator run on one tank of fuel?

This varies greatly depending on several factors:

• Generator Efficiency: Inverter generators are more fuel-efficient as they adjust engine speed to load.
• Load Percentage: A generator running at 25% capacity will run much longer than one at 75% capacity.
• Tank Size: Larger fuel tanks mean longer runtimes.
• Fuel Type: Propane often offers longer runtimes than gasoline per gallon equivalent, but with slightly reduced power output.
  Always check your generator's specifications for estimated runtimes at different load percentages.

Is a dual-fuel generator worth the extra cost?

For many RVers, yes.

• Benefits:
• Fuel Flexibility: Use gasoline when readily available, or switch to propane when it's more convenient (e.g., at campgrounds that sell propane but not gasoline).
• Extended Runtime: Carry both fuel types for longer periods off-grid.
• Propane Availability: Many campgrounds offer propane refills.
• Cleaner Burn: Propane burns cleaner, leading to less carbon buildup and potentially less maintenance over time.
• Easier Storage: Propane doesn't degrade like gasoline, making it ideal for long-term storage without gumming up the carburetor.
• Drawbacks:
• Higher Initial Cost: Dual-fuel models are typically more expensive than single-fuel counterparts.
• Slightly Lower Power on Propane: Generators usually have a slightly lower wattage output when running on propane compared to gasoline.
• Added Complexity: More components mean a bit more to potentially maintain, though modern designs are very reliable.
  For the freedom and peace of mind they offer, dual-fuel generators are a popular choice among seasoned RVers.

Making Your Final Decision: Future-Proofing Your Power

Choosing an RV generator is about more than just numbers on a page; it's about matching power to your passion for RVing. To select the right generator, you need to consider your current equipment and usage patterns, but also think about the road ahead.

• Future Upgrades: Are you planning to add another A/C unit, a larger microwave, or more power-hungry appliances in the future? Sizing up slightly now can save you from needing a completely new generator later.
• Changing Lifestyle: Will you eventually transition from weekend trips to full-time RV living? Your power needs will undoubtedly increase.
• Buffer Room: Always build in a little extra wattage beyond your calculated minimum. This buffer accounts for:
• Altitude Effects: Generators lose about 3.5% of their power for every 1,000 feet above sea level.
• Wear and Tear: As generators age, their performance can slightly decrease.
• Unexpected Needs: You never know when you might need to power an extra fan or a friend's device.
  By thoughtfully assessing your power requirements, understanding the various generator types and features, and keeping future needs in mind, you can confidently choose an RV generator that will reliably power all your adventures for years to come.