Why You Need an Inverter Generator (Best Brands, Sizes, What to Avoid)

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I love inverter generators.

Luuuuuv them.

They are quiet, lightweight, and efficient. And dare I say, kinda cute.

Compare that to the typical conventional generator: a smelly brick of a machine with a full-throated roar and an unquenchable thirst for gasoline.

I want to answer three questions for you:

  1. Why you should purchase an inverter generator?
  2. What is some basic technical info?
  3. What are the best inverter generators for your RV camper?

Let’s start ‘er up.

Affiliate Disclaimer: Some of the product links are on this page are affiliate links. If you click through and purchase, I may receive a small commission at no extra cost to you. Thanks!

Why You Need an Inverter Generator for Your RV Camper

A generator creates 120V AC electricity.

You don’t need a generator while plugged into shore power at a campground.

However, you can’t run any of your 120V appliances while boondocking, dry camping, or Wally camping without a generator.

For a little more information on this, here’s my article about why you can’t run your A/C off your battery.

Even with upgraded battery banks, solar panels, and an inverter, very few rigs can draw out enough power from the battery bank to run your air conditioner, microwave, coffee maker, etc.

So if you want to run appliances while boondocking, you need a generator.

Otherwise, you are restricted to 12V only appliances, like lights and fans.

If you want to know more about camping off battery power, here’s my article series on figuring out your RV power needs.

How an RV Generator Works

All generators have two basic parts:

  1. Engine
  2. Alternator

Here’s a simple video showing how a basic generator works:

An inverter generator adds a third component:

3. Inverter

Here’s the basic difference between a conventional and an inverter generator.

A conventional generator more or less delivers the raw power straight to your distribution panel. The machine has some voltage regulation and basic protection, but what you get, you get.

An inverter generator uses a rectifier to convert the electricity from AC to DC power and then inverts the power back to AC.

This mechanical rigmarole allows the inverter generator to vary its running speed. It can purr, hum, crank or roar depending on how big the electrical load.

Now, why would you pick one over the other?

Conventional vs Inverter Generator

Conventional generators are loud, rumbly, and somewhat crude.

  • Dirty power. The farther you get away from perfect 60 Hz, 120V RMS power, the more “dirty” power becomes. Fluctuating voltage can damage sensitive electronics, like the control boards in your converter, microwave and air conditioner.
  • Guzzler. Conventional generators must spin at 3600 RPM regardless of load, so their run time rarely exceeds 12 hours, even without anything plugged in!
  • Noisy. A typical 3500-watt gas generator is rated at 68-80 db. While this isn’t loud enough to damage your hearing, it is loud enough to ruin your mood.
  • Heavy. Conventional generators are typically built for the construction and emergency homeowner markets. They use open-frame construction. They have steel roll cages, oversized wheels, and bulky steel parts. Most weigh 100 lbs or more.

However, conventional generators cost less. They are also available in larger sizes (5,000 to 10,000 watts), big enough to supply a house during an emergency power outage.

Enter the inverter generator.

  • Filtered power. A high-quality inverter generator uses a microprocessor-controlled circuit board to filter and regulate the output power. As a rule, inverter generators can supply power to more sensitive electronics like televisions, laptops and air conditioners.
    • Hot hint! The best inverter generators have less than 3% THD!
  • Energy-efficient. Because an inverter generator can vary its running speed based on the electrical load, they can chug along at very low engine rpms! This consumes less fuel and gives you a longer run time. Plus, less toxic exhaust fumes!
  • Quiet. Inverter generators are designed to be quiet and portable. A typical 2000- to 3000-watt inverter generator is 48 to 62 Db, quieter than typical conversation levels!
  • Lightweight. Smaller form factors and compact construction allow inverter generators to weigh as little as 38 lbs! Most are 40-60 lbs.

Inverter generators do cost more than their crude cousins. They are available in sizes ranging from 1,800 to 4,500 watts, with the most popular size range being 2,000-3,500 watts.

My recommendation is 100% for an inverter generator. They are well worth the upfront cost. And, your campground won’t hate you! You can run your generator at 8:00 am or 8:00 p.m. without waking up your neighbors.

How to Choose an RV Inverter Generator

Some people will tell you that you need to calculate all the wattage requirements of your RV before purchasing an inverter.

That’s phooey nonsense.

Phooey I say!

(Although, there are other times when you should know your amp draw – like when boondocking off your battery. For that, check out my article here about common RV appliance amp draw.)

Anyways, it’s nonsense because most of your appliances just don’t draw enough power to bother the generator one bit. Why waste your time counting peanuts?

Also, generators are only available in certain sizes! And that’s almost always between 2000 and 4000 watts.

(Sure, Honda makes the 7000-watt EU7000iS, but who wants to spend $5,000 on a generator?! I’d rather buy a boat!)

I mean...who wouldn't want this life?

So you really only have to choose between two or three standard sizes.

Speaking of sizes, you should be aware that generators have two wattage ratings:

  • Surge: The maximum power the generator can deliver for startup loads (for instance, starting a compressor refrigerator).
  • Running: The maximum power the generator can deliver continuously.

Anything with a motor or compressor will typically draw more watts upon startup than while running. These startup watts can be 2-3x more than the running watts!

(FYI, there is no convention for naming a generator based on surge or running watts. Most, but not all, are sold by their surge rating. Check with your make and model.)

So how do you pick a size?!

It really comes down to your air conditioner. They are the most power-hungry appliance on an RV.

Oh, here’s a quick hint: Want to know how many amps a generator can deliver? Just divide the watts by 120.

(Small) Running Watts: 1600-2200W

This is the smallest usable size for an RV.

It will recharge your battery, power your lights and fans, and run small (e.g. 700 watt) microwaves.

If you have a 13.5k BTU or smaller air conditioner with a soft-start, you might be able to turn it on Low or Medium cooling mode. I’d still cross my fingers, though.

If you’re one of the few RVers using an 8k BTU air conditioner, you should be able to get away without a soft-start. If you’re using a 5k BTU window unit, you’re in the clear.

You’ll probably only be able to run one big 120V appliance at a time. For instance, if you’re running your A/C on Cooling Mode, you most likely won’t be able to turn on your microwave.

Of course, your mileage may vary. For instance, if you have a high-efficiency air conditioner, like the Coleman-Mach PowerSaver, you’ll get more bang for your buck.

(Medium) Running Watts: 2200-3000W

This is the recommended size for most RVs and campers.

It’ll run a 13.5k or 15.k BTU air conditioner, even without a soft start.

A 3000W generator can theoretically deliver up to 25A. That’s a lot of power! That’s just shy of the 30A service available at most campgrounds.

So you should be able to live life as normal, running your A/C and microwave at the same time, watching television, etc.

However, you’ll have difficulty running two air conditioners at once, even with a soft-start device.

If you don’t have a soft-start device yet, get one!

You can check prices at Amazon here.

(Large) Running Watts: 3000-4000W

These bad boys can do just about anything.

You want to run two air conditioners at once? No problem!

Want to cook a full pizza in the microwave? No problem! (although for Pete’s sake, what kind of cook are you? It’ll get squishy!)

However, very few inverter generators produce 240V power. So if you have a luxury fifth-wheel or motorhome, you probably won’t be able to use the washer, dryer, or electric oven.

Also, at this size, you’ve lost the easy portability of a small or medium size. The generator will be heavy, at least 80 lbs.

If you’re storing the machine in your RV “basement,” this won’t be a problem. But if you’ll be toting the generator between your tow vehicle and your camper, then you’ll quickly get forearms like Popeye.

RV Inverter Generators Features to Get

Fuel Capacity / Run Time

The bigger the gas tank, the longer the generator will run.

I would recommend a minimum run-time of 8 hours at 25% load. Longer is better.

A run time of 10-12 hours at 25-50% load allows you to continuously run the generator for an evening and through the night while boondocking.

Dual Fuel Capability

Some inverter generators can run off propane or gasoline fuel. Typically, you’ll get more power out of gasoline operation. Still, the propane option is a handy backup!

Parallel Connection

Generators with parallel connection capability can be linked with a clone to double the power.

So two 3,500W generators could provide up to 7,000 watts of power. Nice! All the power AND the portability.

Generally, you need two identical generators to make this work. Different brands don’t talk to each other.

Quiet

Don’t let the decibels fool you. A decibel is a logarithmic measure. That means 70 db is twice as loud as 60 db, which is twice as loud as 50 db!

So small differences in dB make a big difference in perceived loudness!

Almost without exception, cheaper generators are louder. And you go camping to get away from all the noise, remember?

Portability

The sweet spot for portability is 35-50 lbs. People with strong upper bodies can lift 60-70 lbs with proper technique.

Anything above 70 lbs becomes extremely risky to carry around. That’s asking for a back, foot or shoulder injury.

So if you plan to manually carry your generator, it should weigh no more than 65 lbs, which limits your maximum wattage rating to 3,500 or so.

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What Is the Best Inverter Generator for an RV?

Can I be real with you for a moment, Reader?

There are a LOT of articles infecting the web recommending the best inverter generators for an RV. But really, they’re just thinly disguised advertisements for popular products on Amazon.

So let me be honest with you.

Let’s take a look at four brands: Honda, Yamaha, Champion and Generac.

My Top Picks for Portable Inverter Generator

Honda introduced the inverter generator to the world in 1998.

That’s Honda, folks. Arguably the best manufacturer of small engines anywhere on the globe.

And they’re still doing it. And, IMHO, they’re still the best.

The Honda machines ain’t cheap. But they’re good. They consistently lead the pack in almost every metric: lightweight, quiet, clean power, reliability, etc.

If you want the creme de la creme of inverter generators, Honda is where you buy them.

The two most popular Honda models are:

    • 2200/1800W Honda EU2200i
    • 3000/2800W Honda EU3000iS

If you’re a heavy-duty boondocker, get the EU3000iS. Not only do you get the extra power, but maximum run time increases from 8.1 to 19.6 hours.

If you need the ultimate in portability, get the EU2200i. It weighs 47.4 lbs and purrs along as quietly as 48 dB!

The famed Honda reliability is what you’re paying for. They’re designed to run for thousands of hours. They’re designed to be used, not stored in a garage and kicked on twice a year when the power goes black.

But on their heels is another world-class manufacturer: Yamaha!

Yamaha is a long-time competitor to Honda in many industries.

They offer their own lineup of inverter generators. The two most popular products are:

    • 2200/1800W EF2200iS
    • 3000/2800W EF3000iS

Since they’re eager to steal market share from Honda, Yamaha engineers equipped their products with some extra features!

  1. Gasoline fuel petcock: This allows you to drain fuel from the carburetor, reducing problems of stale fuel.
  2. Included battery charging cables. An extra accessory never hurt, right?

You can’t go wrong with a Honda or a Yamaha. In fact, Yamaha may soon win the coveted crown from Honda!

A Word of Warning: Knockoff Generators

Before I get to the runners-up, let’s talk about cheap generators.

Cheap generators are designed to run for a few hundred hours at most. Planned obsolescence at its worst, folks. They’ll fail the moment you need them most.

If you want to buy a Predator inverter generator from Harbor Freight or some no-name overseas knockoff, I can’t stop you.

But I certainly don’t recommend it. A generator is an engine and an alternator. In what world does anyone make a decent 4-stroke engine for a few hundred bucks?

Knockoff products aren’t my thing. I like the guys who do the research to come up with the solution, not the ones who take advantage of lax international patent law to copy-and-paste someone else’s work by substituting cheaper components with lackadaisical quality control.

If a company doesn’t offer domestic warranty service and phone line customer service, that’s a good indication you’re dealing with a knockoff brand. You could be waiting months for warranty replacement parts!

Runners Up: Champion and Generac

There are two other reputable companies in the inverter generator world: Champion and Generac.

Champion has rapidly become the rich-poor man’s favorite for inverter generators. While they aren’t built with the same mechanical lifespan as a Yamaha or Honda, they are an excellent blend of durability and affordability.

Generac is a well-known name in the conventional generator world. But when it comes to inverter generators, they’re still walking in the shadow of Honda and Yamaha. However,

Rather than comparing spec sheets, here’s a simple truth: Champion and Generac are generally priced at 50-75% of an analogous Honda or Yamaha. As a rule, they don’t seem to last as long.

With that said, saving several hundred dollars is nothing to sneeze at. If you don’t plan on running your generator every night, you may find a Champion or Generac generator is sufficient for your needs.

I’ve owned a Champion generator myself, and I was very pleased with it! I was willing to sacrifice a few pounds and a few decibels for the upfront savings.

What About the Big Box Brand Generators?

Lastly, a quick word on the big box brands of inverter generators: Westinghouse, Wen, Craftsman, Briggs & Stratton, etc.

I wouldn’t put any of these brands above the other, necessarily. If I had to pick one, it’s probably Wen. Wen has an excellent reputation for reliability as its price point.

Most of these brands are private-label products. The companies really just act as assemblers, sourcing parts and assemblies from other manufacturers. Almost all the manufacturing and assembly takes place overseas.

That’s true even for “American” name brands like Briggs & Stratton and Craftsman, which gave up their made-in-the-USA heritage a long time ago.

There’s nothing wrong with being a private label product. That’s why they can sell them so cheap. But you’re not getting the same devotion or quality control as, say, a Yamaha.

Again, if all you need is an occasional backup, then a Big Box brand may suit you just fine.

Ross

RV engineer by day, intrepid blogger by night (and occasionally weekends). This website is all about how RVs work, and sometimes why they don't. Bookmark pages that you find helpful, and join my email list for exclusive monthly awesomeness.