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The Best RV Autoformers

Written by Stephen Ryan / Fact checked by William Turner

I love RVing, going out on adventures, and visiting other places, while still bringing my creature comforts with me. However, I am not the only one who loves doing so, and there has been a steady increase in RVers the past years. While this is encouraging as I would meet a lot of like-minded individuals, it can also cause problems. For instance, there are now more RVs in a park than usual. Parks sometimes can’t handle the increase in users plugging into the shore power, so power under-loading and fluctuations are becoming more common.

best rv autoformer

To prevent your RV and your appliance inside from suffering from under loading, you would need a device called autoformer. Since it is an important electricity controlling device, you shouldn’t just go for the first one you find. You must choose the best RV autoformer. If you know nothing about this device or are confused about which one to choose, I’m here to help by providing advice. I’ve listed the finest ones available today.

Top 1

Hughes ‎RV220-50-SP


Weight ‎38 pounds
Amps 50A
J Rating 4800J

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Top 2



Weight ‎21 pounds
Amps 30A
J Rating 2400J

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Top 3



Weight ‎42 pounds
Amps 50A
J Rating 4800J

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Table of Contents

List of 5 Top-Rated RV Autoformer Reviews 2023

1. Hughes Autoformer RV220-50SP 50 Amp Voltage Booster/ Surge

As an RV owner, I have experienced low voltages at RV parks – a very common concern that is easily solved with an autoformer. I used to think that a simple surge protector would suffice until I realized that since most of the RV campgrounds I stay at are significantly older than my RV, these parks are more likely to have low voltages – and as such are more likely to under-supply than over-supply power.

One of my RV park neighbors told me that he got a PI surge protector for his RV, which is what I was initially thinking of getting for myself, but then I realized that low voltages are more common. As the temperature gets to up to 106 degrees Fahrenheit between the months of June to August, the voltage at the RV park also drops down to just around 103V to 108V. Because of this, I thought an autoformer would be a better purchase.

This Hughes Autoformer 50 Amp can boost 103V to a consistent voltage of between 113V-118V. The thing I like most about this product is that it also has a built-in surge protector that can be replaced in case of extreme voltage spikes – which is a significant safety feature. So although an autoformer is expensive, having a built-in surge protector would mean I won’t have to purchase an extra item.

  • Works well and consistently supplies the correct voltage
  • Also serves as a surge protector
  • Built-in surge protector can be replaced
  • Can be set to boost to desired level and adjust to the RV’s specifications
  • Comes with its own cable and lock
  • A bit expensive compared to a typical EMS or surge protector
Even though it is a bit pricey, I think, considering that it protects the RV from under or over voltage (like a typical surge protector) while also boosting the voltage whenever necessary, it will save me money in the long run as I wouldn’t have to replace appliances that are damaged by insufficient voltage. An autotransformer is a must-have for any RV owner, and I am glad to have found the Hughes Autoformer RV220-50sp one because I no longer have to worry about ruining my RV.

2. Hughes Autoformers RV2130-SP 30 Amp Voltage Booster/ Surge

Surge protectors are a very useful tool for RV owners like me, especially since voltages at campsites (particularly older ones) are very unpredictable.

I got a surge protector from PI before, thinking that it would be enough to keep my RV safe from under- or over-voltage. I parked at a nice campsite in Texas once; I found a nice location to park my RV, but a few days in and I noticed that the surge protector would often shut down and I won’t have power in my RV. I checked and it turns out the main supply falls to 105V, sometimes even to 103V in August because of the 104-degree temperature, and the surge protector alone couldn’t handle the under-voltage.

I got this 30-Amp autoformer as it matches my RV’s specifications and fortunately, I don’t have the same problem anymore. I understand it is also available in 50Amp, so that might be better for those with a bigger RV.

I really like that this Hughes RV autoformer has a power cord that has the right length (6 feet) and as such is not a tripping hazard, and that the RV autoformer has the boost function so it can always maintain the right voltage level even when it gets really hot outside.

I didn’t like that it doesn’t say (or maybe I just couldn’t find it) up to how much power surge the unit can handle; although personally, I have not encountered extremely high voltages, it would be nice to know the maximum voltage surge it could take so I can be prepared with the right tools in case this won’t cut it.

  • Comes with its own surge protection unit – so it’s like two tools in one
  • 30Amp capacity and can be easily installed into the electrical system
  • Dependable voltage booster for inconsistent and/or low voltage source
  • Ensures safety and has the LED Park Power diagnostics
  • Might not be suitable for extremely high surges in voltage
I wish I had bought this Hughes Autoformer 30 Amp instead of the surge protector I got initially because then I would have saved a lot of money and I would not have had to go through all that stress for such a simple concern.

3. Hughes Performance RV22050 Autoformer

Every RV deserves to have a trustworthy autoformer. This is to protect appliances from being damaged due to low voltage. If you wish to prolong the life of your RV appliances, then you need to enlist the service of the best RV autoformer in the market: Hughes Performance RV22050 Autoformer.

There are so many things that I like about this 30 amp autoformer. First is the fact that this is a weather-resistant product. It can withstand rapid changes in moisture and heat inside the RV. This means that you will be able to enjoy the unit for a very long time. It can last you even decades.

Next is the performance. It has an automatic 10% boost, which is very good for our appliances inside the RV. It can manage for as low as 99 volts. I love that it has LED indicators that lets me know that it is turned on and working, as well as informs me about errors in the power source. Through this feature, I can avoid any kind of electrical problems before they happen.

What I don’t like about this autoformer is its weight. It’s heavier compared to similar autoformer brands in the market. This makes it a little challenging to install, especially if you are doing it all by yourself.

  • Weather-resistant
  • Has LED indicator lights for convenient monitoring
  • Can manage up to 10% voltage boost
  • Durable
  • Easy to use
  • Heavier compared to other autoformers in the market
After weighing all the important details, I conclude that the Hughes Performance RV22050 Autoformer is one of the best RV autoformers in the market. It really protects appliances from being damaged due to low electricity surge. Furthermore, it has a reliable method of informing the user about the real-time electric diagnostics that could help you manage your power better. If you want to prolong your RV appliances, the best autoformer to use is Hughes Performance RV22050 Autoformer.

4. Power Master VC-50 Voltage Controller

With the increase in RVers, I’m finding that power fluctuations happen more and more often these days. Whether I park at RV parks or at campsites, I experience under loading maybe six times out of ten. I know for fact that when appliances receive less power than expected, they tend to get overworked. And when this happens, the result would often be that the appliance would end up damaged. And since I didn’t want to spend loads of money replacing or fixing damaged appliances in my large RV, I searched for a voltage controller. Since I would need a 50 Amp autoformer, I chose this one from Power Master.

Power Master VC-50 has a dual function: as a voltage booster and a surge protector. The booster ups the voltage to make sure your RV receives the right voltage, which is usually 110v. There was a time when the voltage from the source was only at 103v, which is very low for my appliances. The devices will work, but they would end up overheating due to the machine being overworked. It’s a good thing I have the Power Master to make sure I get the right number of volts. According to the specs, it can boost up to 12% voltage, which is the highest I’ve seen in any boost transformer.

I love that it also serves as a surge protector, so when the opposite happens and power gets over 110 volts, I won’t trip my RV’s wires. In the past, I had experienced a couple of blackouts and some appliances popping due to overloading. After all, it’s hard to consistently monitor the fluctuating power, especially at night. Ever since I installed this autotransformer and surge protector, I never experienced any such issues in my large RV.

The only downside I can think of is that it is a tad bit more expensive than the rest. But since it comes with a commercial-grade surge protector, I believe it’s worth it.

  • Dual function as a voltage booster and surge protector
  • Can be hard-wired into your RV
  • Made in the USA
  • Comes with a two-year warranty
  • Can manage up to 12% voltage boost
  • Expensive
Even with its price, this voltage controller from Power Master is definitely worth it. With its two year warranty, you’ll be hard-pressed to find a fault with this device.

5. Southwire 30A and 50A Voltage Regulators

When setting out for an adventure, you have to make sure that your appliances and devices are durable and can withstand bumpy roads. This is why durability is one of the most important aspects of any item inside a camper. If you are looking for a really heavy-duty autotransformer, Southwire’s voltage regulators may just be perfect for you.

I have two kinds of RVs: one is really large and the other is about average size. I bring the smaller one on my lone trips, while I use the large one for trips with families and friends. The smaller one has a power capacity of 30 Amps, while the bigger one requires 50 Amps. It’s but normal because of their size.

Based on experience, power can under load in many campsites. I have experienced a couple of blackouts before, and when I saw that I was the only one who didn’t have power, I knew then that it must be due to my connection and not the park’s fault. I found out too late that the source power box is not delivering enough voltage, causing the machines to get overworked in trying to pull enough power to keep them running. I learned my lesson the hard way, so I purchased this Southwire voltage regulator.

I opted for the 30 Amp autoformer for my smaller RV. What I liked most about this 30 Amp autoformer is that it looks really heavy-duty. No amount of rugged travel would cause any issues towards this regulator. Plus, its enclosure is weather-resistant, so it’ll work even under varied weather conditions.

I also love that it’s a set-it-and-leave-it item. There’s no need for me to check it regularly to see if it has to be turned on. It monitors the voltage continuously and regulates the voltage once it drops. I’m happy to report that I haven’t had any issues with power ever since I installed this one. It also gives me peace of mind that it is running because of the LED indicators.

What I don’t appreciate with this product though is that it doesn’t protect against power surges. So if the power goes over 110 volts, my wires are doomed. What I did was install a separate surge protector.

  • Heavy-duty
  • Has a weather-resistant enclosure
  • Fully automatic
  • Has LED indicators
  • Can manage up to 10% voltage boost
  • Has no surge protector
This device works really well in protecting your RV’s power. Just make sure to couple it with a surge protector as it cannot do anything about power overload.

What to Look for When Buying an RV Autoformer


With the RV’s large size, it comes with a premise of a spacious area, with so much potential for comfort and décor! In it, one can have a decent sleeping quarters, a functional kitchen where one can cook comfortably, a working comfort room for when you need to take a quick shower or to answer the call of nature, and a homely receiving area where your passengers, such as loved ones and friends, can all hang out and chill as you try to enjoy yourselves on the road! It has the space to carry your much needed everyday items, maybe even a decent entertainment system, as well as other travel, camping, and RV maintenance equipment. Yes, it can carry all that!

But what makes all that load possible for the RV to carry around, all the while traveling great distances? The answer is simple: it is because the RV is also a beast underneath! Made to not just carry passengers from Point A to Point B, but also to give them ease and accommodation as they travel, the RV is the perfect semblance of a home away from home, with wheels and engine that can cover any forgotten country road or beaten paths of any terrain long lost. With the size and the strength like that of an RV, you would never have stressful long drives again just to camp out on the great outdoors!

Knowing how to drive an RV is only half the battle, however. The other half of the challenge is keeping it, maintaining it to be in such good travel conditions. But how does one do that, exactly? From one RV owner to another, the answer is simple; you should use only RV-specified products and items. Why? Because most everyday tools and equipment are not up to par with RV standards, that is why appliances and tools are made specifically to cater the RV’s specifications.

One of the RV equipment you should not overlook is the RV transformer. If you want to grab one for yourself but do not know how to pick one, here are some factors to consider when buying an RV autoformer:


The automatic transformer, or autoformer for short, is a device that helps you in stabilizing voltages that comes from the power supply and into the appliance or the equipment. Take for example simple appliances such as microwaves and coffeemakers. Typically, these things run on 1200 watts, add those to the overall wattage for refrigerators, entertainment systems, and converters and you might find yourself needing a total of about a little more than 3000 watts. Your RV, which previously can only support a maximum of 3000 watts, can now support up to 3600 watts with any decent autoformer! What it does is it changes the voltage-amperage dynamic. It lowers the amperage and raises voltage consumption, which makes the appliances run smoother since they work better with lower amperages and higher voltages.

The only thing that makes sure this is happening when you use your autoformer is to choose one with manufactured with high-quality materials. Subpar items might find ways to cut production costs and make the product cheaper, however as we all know equipment dealing with electricity should not be looked over because one small mistake, one small power surge, might spell disaster not only for the passengers but also for the RV itself. Do not be afraid to ask for the specific details regarding the product’s make to be able to utilize the function properly.


When getting an RV autoformer, consider also the functions and operations where you might need it to be able to get the right specs. For example, do you need an RV autoformer to accommodate appliances and equipment for light usages, or heavy, long usages? Do you only need it for simple household equipment or do you plan to use it to expand your electricity capacity further?

The RV autoformer is specifically built in order to avoid those energy fluctuations that are unavoidable when you use different power supplies. These fluctuations can permanently damage the motors and compressors of multiple tools and equipment. The autoformer helps stabilize the flow of electricity by utilizing its self-adjusting mechanism in accordance to the power available, making it safer for everything and everyone. As you might have predicted, a power failure on the road might be disastrous for a trip, and can permanently damage your stuff. Do not make this mistake by considering the functions you need first before buying the autoformer for your RV.


After meticulously planning out what RV autoformer to get with regards to its make and its capacity to perform the functions you want, then it is time to consider the pricing. Here is where the branding comes to play. It is not surprising that many RV owners are loyal to certain brands because most brands entail great quality because of the materials they use, and the capacity of the product. However, do not be afraid to look into other brands if you feel unsure going with your brand again. After all, buying an RV autoformer is a long-time investment that owners usually make early on.

Don’t let an electrical concern put a damper on your adventures, especially since you can’t always find an electrician to help you sort everything out when something arises. Properly evaluate an RV autoformer from the basis specified above, as well as based on the reviews of people who have already tried these products (such as me!)

Other Important Factors to Consider


What is an RV autoformer?

An autoformer is designed to increase the voltage that your RV receives whenever the voltage is less than desired. This prevents damage to your appliances brought by low voltage. In essence, it is a transformer that you use on your camper when plugging in an RV park or campsites.

How does an autoformer work?

Many RV owners do not understand how an autoformer works. This is the reason why some of them still don’t have this piece of equipment installed in their RVs.

Simply put, an autoformer works by adjusting the voltage that flows into your RV. It regulates the power output based on your actual power demand. If the electricity coming from the source is very low, the autoformer boosts it in order for your appliances to work properly.

For instance, some output power boxes in campsites send as low as 100 volts. However, RV appliances usually run at 110 volts. Because 100 volts is too low for such devices, they tend to get overworked, trying to pull more current to get the desired voltage that they need. This causes overheating and eventually destroys the machine. An autoformer can prevent this from happening by accepting the low voltage and boosting it to the desired voltage of 110 volts or higher. This prevents your appliances from getting damaged.

What are the different types of RV autoformers?

The different variants of autoformers are usually based on their electric current carrying capacity, as well as extra features.

There are two types of autoformers based on current capacity, and these are the 30 Amp autoformer and the 50 Amp autoformer. Choose one based on your RV’s current rating.

Another variation of autoformer is based on its features. Some are just basic transformers or voltage controllers, while others are dual function, serving also as RV surge protectors.

Why do you need an autotransformer for RV? (Benefits)

Replacing damaged RV appliances is definitely expensive. However, it can be prevented if you have a reliable piece of equipment that would stabilize the electrical flow. This equipment is the autoformer.

Unfortunately, not all RV owners are aware that they need a reliable autoformer to ensure their appliances’ optimal performance. If you are confused about the advantages of having one, here is a couple of concrete example why you should have it in the first place:

  • It prevents your appliances from being overworked. Appliances work harder if they are getting low voltage. Because of this, the amperage increases, this then leads to malfunction. An autoformer can stop this from happening as it will automatically boost the low voltage coming from the power source.
  • It can protect your RV from polarity and phase reversals due to wrong power output installations.
  • Dual-function autoformers have built-in surge protectors which protects the RV from power overload.
  • Allows you to use your modern RV in old parks that haven’t updated their power pedestals.

Finding the right one can be quite challenging, as manufacturers have to upgrade their design every year to make life inside the RV easier and more comfortable. If you are going to purchase one for your RV, make sure that you consider not only the brand or price but also its performance as observed by satisfied customers.

All in all, an autoformer will give you peace of mind that your RV appliances are safe whenever you plug your camper in your home or in a campsite pedestal.

Frequently Asked Questions


What are good RV autoformer brands?

There are only a handful of autoformer producers out there. Here are the best autoformer brands available:

Hughes Autoformers – this company was founded in 1995 by an RV enthusiast himself. This guy named Hughes experienced low voltage supply in various campsites in the country, which damaged many of his RV appliances. He created his own autotransformer and helped thousands of RVers prevent electric damage to camper appliances. Since the founder is an avid RV user himself, he was able to produce autoformers that fits every trailer’s needs. The company’s autoformers are highly reliable and last decades.

InnoTechRV – this company manufactures various RV accessories. They only have one autoformer in their product line – the Power Master VC-50, but it is a great and reliable product. It is both an auto-transformer and surge protector.

Southwire – this company focuses on electrical connections and transmission devices. They have a line of products focusing solely on power transmission in RVs, such as power cords, connectors, and of course voltage regulators.

What is the difference between autoformer vs transformer?

The main difference between the two is that an autotransformer has one winding, while a transformer has two: the primary and the secondary. Because of this, the voltage adjustment is typically smaller in an autoformer than in a transformer.

The disadvantage is that an autoformer can’t be used to reduce high voltage. For this reason, an autoformer would usually be paired with a surge protector. Sometimes voltage controllers are dual function as it houses both an autoformer and a surge protector.

What is the right sequence to use an RV autoformer with a surge protector?

The correct sequence for using an RV autoformer that has a motorhome surge protector is autoformer-surge protector-RV.

RV owners must connect the RV autoformer device to the RV park electrical power pedestal before plugging in the motorhome surge protector. Only when these connections are secure can RV owners link the system to the RV.

Plugging in the motorhome surge protector before the RV autoformer will cause the device to shut off continuously because of the RV park’s low voltage.

What do I do if my RV autoformer is boosting voltage too high?

In such situations, RV owners must determine if the problem is due to a malfunctioning autoformer or loose wirings.

  • First, disconnect the power supply to the electrical plugs and cables.
  • Assess the wirings for integrity before reconnecting them.

It should solve the issue of an excessive voltage boost from the RV voltage booster or autoformer.

RV owners must consider bringing their autoformers to a licensed service center if the wirings are not loose and the device still boosts the voltage excessively. Seasoned RVers advise against DIY autoformer servicing because it might damage the device further.

Can I use an RV autoformer with a generator?

Yes, RV owners can use an autoformer for RV with a generator, especially if the former is hardwired to the motorhome. RV autoformers increase the voltage through an electrical system if it senses low voltage input.

Since generators deliver more or less constant voltage, it should not be an issue if RV owners link them with a hardwired autoformer.

It also does not make sense to use an autoformer-surge protector combination with an RV generator. There is no issue between the generator and the autoformer. Unfortunately, the electrical energy-producing device might be ineffective with the autoformer’s surge protector component.

Will an RV autoformer decrease the voltage for other RVs in the campground or RV park?

Yes, an RV autoformer can reduce the voltage available to other motorhomes in an RV park or campground.

It is worth comprehending that autoformers serve as voltage boosters when they sense the incoming voltage from the RV park is too low. These devices protect expensive motorhome equipment and appliances from malfunctioning or meltdowns due to low amperage.

Although autoformers protect RV appliances, these devices also tax an RV park or campground’s already strained power delivery system. RVers without autoformers plugged into RV park pedestals will also suffer under-voltage and risk blowing their motorhome equipment.

How to set up and use?

An autoformer is an electronic device that should be handled with utmost care. If you have little to zero experience installing an autoformer, we suggest that you contact a professional electrician to do it for you, especially if hard wiring is necessary.

However, if you are confident in handling electrical equipment, you can follow these easy steps to set up your plug-style portable autoformer:

  1. Place the unit on the ground, with the handle facing upwards.
  2. Connect the autoformer cord to the RV electrical post.
  3. Connect the RV cord into the autoformer.
  4. If you are going to use an extension, connect it to the camping park post, then connect the autoformer into it, and the RV into the autoformer.

Always remember, though, that this kind of work should be handled with utmost care. Make sure that the autoformer is well-ventilated to prevent it from overheating. Finally, use the autoformer as it was designed to function. Do not attempt to modify it as it could compromise not only the integrity of your RV appliances but also the safety of the occupants inside.

How to care and clean?

If you are going to clean your autoformer, make sure that you do these simple precautionary steps:

  • Always disconnect any electrical connection from the power source. This is to prevent any power surge from damaging your RV appliances. Once all the necessary precaution is done, only then you should plug the appliance that you are going to use.
  • Avoid using wet cloth. Water and electricity don’t match and it is surely a recipe for disaster. If you think that your autoformer is dirty, the first thing you should do before cleaning it is to disconnect it from the power source.
  • If you think that there is something wrong with the autoformer, make sure to contact a professional electrician. This way, you can prevent making further damage to the unit that may lead to premature replacement.

After using, keep the autoformer in a place where there is not much humidity, especially if your unit is not weather resistant.

Where to buy?

You can purchase autoformers in your favorite home improvement stores such as Wal-Mart, Lowes, and Home Depot. However, although a necessary item, it is not always easily available in these local shops. You can visit an RV retail store, or check Amazon.com. The advantage with purchasing from Amazon is you can easily find the exact unit you need. You won’t have to settle for just what is available.


For so many years, the people of olden times would have to gather people, create a group for themselves, and set out to travel to distant lands and places by utilizing the caravan system. And although ‘caravan’ is oftentimes used these days to describe fun trips, in reality, it was a long and hard way to travel. That is why the world rejoiced the day the RV was first produced! The RVs, or recreational vehicles for those unfamiliar with the term, are vehicles that are visibly larger and stronger than most cars and vehicles out there. Mostly defined by their hulking size and the roar of their engines under the hood, these vehicles are the modern-day embodiment of a road trip, a one-vehicle caravan that is able to cross desert roads and beaten paths altogether!

But you enjoyment in using your fifth wheel can be cut short when you encounter malfunctions, especially with anything related to electricity. What happens if your appliances suddenly seize to work properly?

While you are free to choose what kind of appliances you want to use in your RV, you still need a reliable piece of equipment to protect it from low voltage and sudden power surge. This is where you need to find RV autoformers. Choosing the best RV autoformer may be difficult, but this review will give you an idea about the performance of the units offered by the leading brands in the market today. This way, you can have an educated choice about the units that you are going to include in your shopping list. An informed decision about the right autoformer can help you save time and money and most of all – your very own appliances. Don’t wait until a blackout or a tripped wire happens to you, for your safety, get an RV autotransformer.

4.9/5 - (8 votes)