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2 Best RV Autoformers Every RVers Should Own

Written by Philip Lopez / Fact checked by Paul Lemaire

best rv autoformer

As an RV owner, my greatest fear is to have damaged RV appliances. Power spikes and very low voltage can ruin sensitive electronic equipment and appliances like AC units. This is where the best RV autoformer can do its job.

An RV autoformer serves as a protective barrier between your camper and the electric pole. When it senses a low voltage situation, it automatically boosts the power to normal levels. It also helps prevent power surges and spikes to keep your electronics and RV secure.

Here are some things to consider to ensure that you choose the right autoformer.

  • Material: The material of the device can tell you how long it will perform in the harshest conditions. The conductors are the most vulnerable part of the autoformer, so make sure that they’re wrapped in a durable material, like copper.
  • Ratings: The current rating depends on how much your campground needs. For instance, you plan to camp with a 50-amp service. Make sure that you choose a 50-amp autoformer model in this case. Take note of the joules rating of the integrated surge protector as well. Hughes autoformers, for instance, offer more than 2,000 joules of protection.
  • Protection: A dual-function design is ideal because it prevents low voltage and power surges. Both these features can lengthen the life of your AC units and other sensitive appliances.

You can learn more about autoformers in our buying guide below. For now, let’s review our top choices and find out which one is better.

Table of Contents

Best Autoformer for RV Reviews

1. Hughes Autoformer RV220 50SP


In the past, I needed a separate TRC surge guard and an RV voltage booster to protect my electrical appliances from power source issues. Things changed when I found this Hughes autoformer, which gave me adequate voltage and surge protection all by itself.

More specifically, this RV voltage regulator 50 amp model provides a 10% electrical boost when the voltage drops at RV parks. It starts working when the power goes below 113 volts and stops when it reaches 115 volts.

Plus, the built-in surge protection can absorb up to 4,800 joules of energy. This rating is more than enough to protect my hand tools, computer, and PS4 from faulty park power.

The best part is that the surge board is replaceable. When the surge protection function goes bad, I don’t have to replace the whole unit. I just have to replace the board, and everything goes back to normal. Also, I love the lock to help keep the unit secure and the long power cord for easy hookup to electric outlets.

Thanks to the indicator lights, I’m pretty much informed on what’s going on. I keep the device hooked up to shore power, and the LEDs automatically turn yellow when the boosting commences. They turn off when the voltage has reached normal levels.

My only dislike is the price because it was more expensive than I expected.
  • Can boost voltage to protect RV appliances
  • Offers high RV power protection with 50 amps capacity
  • Provides protection from any power overload up to 4,800 joules
  • Has LED lights to indicate a boosting function
  • Separate surge protector for a cost-effective replacement
  • Comes with a lock for security and a long power cord
  • A bit expensive
Overall, the RV220 50SP is an excellent piece of safety equipment for high RV power loads. This 50 amp autoformer is both a surge protector and a voltage boost device, helping camper owners feel safe using appliances while traveling.

2. Hughes Autoformers RV2130-SP


The RV2130-SP is one of the best RV voltage boosters with a built-in surge protector function. This 30 amp model is lighter than its 50-amp counterpart, so it’s more portable and won’t take up much space in the rig.

Most RV campgrounds I visited use a 30 amps service, so having this particular model is quite handy. I appreciate the lock of the voltage booster because it assures me that no one will steal it from the power pole. Thankfully, the power cord is long enough to reach the electric receptacle.

Like the 50 amp model, this one has a boost indicator light. Similarly, it does an excellent job of increasing the low voltage by 10% as promised.

What I like most is the price. This autoformer plugin is way more economical than the 50-amp model above. With 2,400 joules of surge protection, I think this device is more than enough to protect my electronics like an electric stove, AC unit, and microwave.

However, this plug-style portable autoformer will be useless when camping in a 50-amp RV park. Users should make sure their campground provides 30 amps of power.
  • Prevents any power surge up to 2,400 joules
  • Boosts voltage to prevent low-voltage damage to appliances
  • Lightweight, compact, and portable to use
  • Lock to keep the unit secure from thieves
  • Has a long power cord to reach electrical outlets and boost indicator light
  • More budget-friendly than the 50-amp model
  • Can’t be used for 50-amps service
Altogether, this model is a good autoformer for RV because it’s portable and economical. It also works as both an autoformer and a surge protection unit, so users get a lot of bang for their buck purchasing it.

What to Know Before Buying RV Autoformer


RV autoformers are important for the protection of your electronic devices, so you should only choose the best one. Here are some things you need to understand before you hit that purchase button.

The Different Types Of RV Autoformers

This safety device comes in many varieties with different capacities and features. Learn about each type below.

According to capacity:

  • 30 amps: This type of autoformer is often more compact than the 50 amps model. It’s more affordable, but it can only handle up to 3,600 watts of power.
  • 50 amps: These models are more versatile because you can use them with 30 amps of service using an adapter. They’re a juggernaut in terms of capacity and surge protection but are more expensive.

According to features:

  • Basic autoformers: These models are not very versatile. All they do is increase the voltage when it goes below normal to protect electrical equipment.
  • Dual-function: If you like a more advanced unit, look for a model like the Powermaster VC50, which works both as a voltage controller and a surge protector. Most Hughes Autoformers also belong to this category as they are dual-function.

Benefits And Drawbacks of RV Autoformers

Also known as an auto transformer, an autoformer is ideal for powering a newly repaired device slowly. The voltage control function of the autoformer helps prevent the fixed device from getting fried again due to power spikes and surges.

In addition, long power lines are vulnerable to low voltage. When your appliances are too far from their outlets, an autoformer can boost the power to normal levels. This device adjusts the output depending on the load demand, making the appliances operate efficiently and smoothly.

However, autoformers may use a lot of electricity.

Autoformer Vs Transformer

An autoformer uses less material than RV transformers, so it costs less. It’s also more efficient because it uses only one winding instead of two. Plus, with a lower voltage drop in resistance, the voltage regulation of autoformers is also better.

In terms of physical appearance, autoformers are more portable. They’re easy to travel with and install because they’re smaller than traditional transformers.

What To Look For In RV Campground Autoformers

To ensure that you get the best autoformer for your electrical connection, look for these features.

  • Protection: A boost transformer offers voltage adjustment while providing surge protection. Meanwhile, dual-function models do the same thing while having built-in surge protectors to protect your RV electrical system. Modern RV models even provide additional protection from reverse polarity.
  • Power Ratings: Determine what service your campground is providing. If it’s 30 amps, then go for a 30 amps model. A 50-amp design can work with a 30 amps outlet as long as you use an adapter.

If the autoformer has built-in surge protection, check the joules rating. A higher value means more robustness in fighting multiple power spikes and surges.

  • Durability: You want the autoformer to be durable so that it will last for many years. Look for copper windings because they’re weather-resistant and will fight corrosion better than their aluminum counterparts.

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


The RV autoformer should be installed on the power pedestal prior to the surge protector. Doing the opposite will cause constant shutdowns when the RV park is running low voltage. Once these two devices are set up, you can link the connections to your RV.

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

Oftentimes, loose connections cause the autoformer to boost too high. When this happens, you can locate the loose electrical connections and tighten them. If it’s still within the warranty period, you can return the product to the manufacturer for service.

Can I use an RV autoformer with a generator?

Sure you can. The generator can pass clean, regulated power to the autoformer. Consider adding a transfer switch for a safe transfer of load and an extension cord if necessary.

How do I quickly test the voltage in an RV outlet?

An easy way is to use non-contact voltage testers. First, insert the tip into the hole of the outlet. You can also hover the tip on the wire that you want to test. The tester will sound and flash if it detects current.


Recreational vehicles need the best RV autoformer to protect sensitive appliances from power surges, spikes, and low voltage.

We recommend the RV220 50SP from Hughes Autoformers because this model can provide the correct voltage for safety. Also, buyers can simply use a step-down adapter plug when they need this device for 30 amps service.

As always, choose a product that fits your needs. Conduct regular maintenance, so the device will last for many years. When in doubt, ask a professional to help you with your choices.

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