Can You Run an RV Generator While Driving?

Can You Run an RV Generator While Driving

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Having the right RV generator means you have on-demand power when dry camping.

Be it on the campsite or the side of the road, a flip of a switch and you have running power to keep you comfortable.

That brings us to a good question.

Can you run your RV generator while driving? Yes, you can run both a built-in and portable generator while driving your RV. However, there are a few things to consider when running a generator while traveling.

In the rest of this post, I’ll talk about everything you need to know to safely run an RV generator while traveling. 

We’ll also be looking at the rules that you need to go by if you want to run your generator while driving.

Lastly, I’ll tell you about alternative methods of powering your appliance when driving if you want to avoid running your generator.

Let’s start by answering, why would you run the generator while driving in the first place?

Do you Need to Run the Generator while Driving an RV?

There can be quite a few reasons to run your RV generator while driving. 

RVs come with a wide variety of appliances that differ in how much power they draw.

Though, most small appliances can be powered with your house batteries.

However, to power those high draw appliances, you need to fire up your generator.

Of them, your rooftop AC is on top of the list.

Read More: Here is a guide that will help you find the right size portable generator for your RV air conditioner.

But, why would you need to run the rooftop air conditioner?

In motorhomes, the dash ACs are designed to cool the cockpit area only. But, when you’re traveling with family and pets, under the sweltering sun, you need to keep the living area cool too.

Furthermore, your RVs dash AC may be out of order in the middle of your trip, and using your rooftop AC is your only option to keep cool.

The rooftop ACs need a lot of power to operate and the alternator of your motorhome or your house batteries are too small for it.

You just have one option: fire up the generator to keep your RV cool in transit.

Note: Running the rooftop AC on the road will eliminate the need to run the dash AC. This will reduce fuel consumption, increase your RVs MPG, and boost the engine’s power.

With towable travel trailers, however, you just want to run the air conditioner so you don’t have to get into an oven once you reach the campsite.

Pro Tip: To cool a travel trailer, start your generator and run the rooftop air conditioner 1-2 hours before you reach your destination. This will also save on fuel and bring down the interior temperature to an acceptable level.

Another important reason to run your generator while driving is to power your refrigerator.

Your refrigerator stores the most essential things for boondocking, i.e. food. You don’t want to reach the campsite only to find out all the food in your refrigerator has spoiled due to lack of power.

However, most RVs come with refrigerators that are designed for RVs. Meaning, they can run on both electricity and propane. 

But, if your RV comes with a residential fridge, you’ll need to run your generator to power it.

Lastly, you’ll have to run the generator to charge the house batteries on cloudy days when solar isn’t producing electricity. It’s also a good way to recharge the batteries if you have a loud generator that you don’t want to run on the campsite.

Note: Charging batteries with generators is only necessary for travel trailers, as most motorhomes use the engine alternator to charge the house batteries while in transit.

Running your rooftop AC, powering your refrigerator, and charging house batteries are the three reasons I like to run my RV generator when traveling.

However, I have seen and know people that also run the generator for a few reasons that will be considered minor, especially while in transit.

They run the generator to use some kitchen appliances, to power the entertainment systems, use the washing machine, etc. However, these are needs that, in my opinion, can be avoided, especially while driving.

Now you know the reasons why many choose to run their RV generator while driving. Now, let’s take a look at the different types of RV generators.

Types of RV Generators

Types of RV Generator: Onboard and Portable

There are two different types of generators in use, depending on the type of RV you have. Most motorhomes come with a built-in model and others including towable RVs use portable generators.

Built-in RV generators are fixed in your motorhome by the RV manufacturer. They are very securely integrated into your RV in terms of electrical connections, fuel source, and mounting.

They run off the same fuel type and source that is used by your motorhome. To run a built-in generator while driving, you just have to push the ignition button located inside your motorhome and you have power.

Most importantly, they can be run during any weather type, be it rain or snow. The dedicated compartment removes all hazards from the elements, giving you the peace of mind to concentrate on the road ahead.

Portable generators on the other hand are not fixed to your RV and usually don’t have a dedicated compartment to store them. They are generally used by towable travel trailers and converted bus-type homes on wheels.

They have their dedicated fuel source and can use either gas, propane, or both to run.

Read More: Here is a great post that reviews some of the best dual fuel portable generators for your RV.

The challenges of running a portable generator while driving are far greater than their built-in counterparts. That’s why we’ll be focusing more on the portable models in the rest of our post.

Let’s start by looking into the most important considerations to keep in mind before running your RV generator in transit.

Things to Consider before Running Generator while Driving

If you have been camping for a while you know the things you need to keep in mind when running a generator.

However, running a generator while driving an RV means there are few more things to add to the list.

Let’s start with the most important considerations.

01. Safety

Safety Measures

Safety is our #1 priority, when it comes to running a generator, especially while driving.

When you have a built-in generator that has been installed by a professional, you have very little to worry about safety.

On the other hand, running a portable generator while driving is also safe, given you keep a few things in mind.

The first question that comes to my mind when thinking about running a portable generator on the road is:

Where do I keep the generator while it’s running?

You can’t just keep a running generator inside the travel trailer. This is the perfect recipe for a disaster.

Firstly, combustion engines of generators produce toxic gases with Carbon Monoxide being the most lethal. It’s a colorless, odorless, and flammable gas that kills.

Note: Though, most modern portable generators come with a safety mechanism that shuts down the generator if there is an increase in the level of gases around it. But, this won’t serve our purpose if the generator stops running.

Secondly, the generator will tumble around while on the road which will damage it physically. Additionally, the tumbling generator may spill fuel, increasing the risk of a fire.

On the other hand, running your generator on the back of your truck will also make it tumble if not secured. Plus, you now have the added risk of your generator jumping out of your truck, destroying itself or the vehicle on its path.

The solution?

You need to mount your portable generator on your RV to prevent these mishaps. I have a great post that talks about the 3 most secure ways to mount a portable generator on your RV.

Moreover, with built-in generators, you don’t have to worry about the wiring. The wiring is away from the view and reach.

However, with a portable generator on the back of your truck or mounted on the RV, the power cable will run from the unit to the RV. In most cases, the power cord will be visible, hanging on the side of your RV.

You need to secure the power cord from the generator to the trailer because wind forces from driving may pull the wire out and damage other vehicles.

The most secure way would be to permanently run the cable under your trailer to the distribution board, done by a professional.

Note: If you run the cable underneath the trailer, make sure the cable won’t get damaged if you bottom out the trailer. A damaged wire will increase the risk of short-circuits.

Stopping to refuel at the gas station

Gas Station Warnings

You’re well aware of the various warning signs at the gas station. They mostly warn you about the different fire hazards.

Of them, the one particular warning sign that concerns us here is the warning about turning your engine off while refueling. In short, the fumes from gasoline or diesel can catch fire if they come in contact with the running engine and its electronics.

This is especially crucial when refueling a portable generator that is running or is hot. Make sure to turn off the generator at least 10-15 minutes before stopping to refuel.

Additionally, you need to keep static electricity in mind when refueling.

Static electricity is generally harmless but while refueling, it can be very dangerous. A static current can cause a spark when the driver touches the fuel nozzle causing a flash fire in cold and dry weather.

Check out this video to know what static electricity can do at a gas station. 

Pro Tip: Touch a piece of metal (car door or the body of a gas pump) before touching the gas nozzle.

02. Rules on the Road

By law, there are no rules that prohibit running RV generators while driving depending on the type of generator or fuel it uses.

However, some laws regulate the noise and emission level your generator needs to be under, depending on the state you’re in.

Every state has a law that puts a limit to the amount of noise a vehicle can produce at a certain weight rating. In general, the noise produced by a vehicle engine is far lower than the noise produced by the generator.

The following chart will show you the acceptable numbers in various states of the US.

StateGross Vehicle Weight Rating (GVWR)Maximum General Noise Level (in db)Exhaust Systems Information
Arizona
CaliforniaAll80 dbAExhaust shall not be directed to the side of a motor vehicle between 2′ and 11′
above the ground.
Montana
New York<10,000 lbs


>5,999 lbs
76 dbA@ <35mph
82 dbA@ >35mph

86 dbA@ <35mph
90 dbA@ >35mph
OregonAll80 dbA
South Dakota
Utah

Get the list of all the states at the Recreation Vehicle Industry Association (RVIA).

Then comes state laws that check if your vehicle and generator are CARB compliant. A CARB-compliant engine simply means the engine produces less harmful emissions, thus keeping the air cleaner.

Apart from California, here are the names of the other states that follow this emission law very strictly. The states include Connecticut, Delaware, Maine, Maryland, Massachusetts, New Jersey, New Mexico, New York, Oregon, Pennsylvania, Rhode Island, Vermont, Washington state, and Washington D.C.

If you’re in one of these states or passing through one with a running generator, make sure your generator is and says it’s CARB compliant. Failing to comply with the law may incur a hefty penalty of up to and above $1000 per day.

Note: It’s a good practice to turn off the engine of your vehicle including your generator if you’re stuck in a traffic jam at a tunnel. Tunnels are confined spaces and running an engine can quickly increase the level of toxic gases.

03. Fuel Consumption

Low Fuel

Irrespective of the type, the fuel consumption of a generator mainly depends on its power out and the amount of power that’s being used.

Portable generators are equipped with dedicated gas tanks. Whereas, built-in generators use the type of fuel (gasoline or diesel) from the same tank that the motorhome uses to run.

This brings us to a good question: 

Will my motorhome MPG be affected if I run the onboard generator?

No, your motorhomes MPG will not be affected by running the onboard generator. But, the total mileage the RV could travel in one tank of gas will be affected.

Confused? I’ll clarify.

Let’s say, your RV comes with 20 gallons fuel tank and burns about a gallon of fuel for every 15 miles you travel.

So, you’re driving slowly, keeping the safety of your family in mind, and enjoying the view around. This way, you’re crossing roughly 15 miles every hour.

It’s a hot day and you have your generator running to power your rooftop AC, fridge, and a few other appliances. Your onboard generator is sipping about a gallon of fuel every hour.

In this scenario, you’re using about 2 gallons of fuel every hour. That means, of your 20-gallon fuel, 10 gallons will be consumed by your generator.

With the remaining 10 gallons, your RV will be able to travel 150 miles approximately.

However, if you didn’t have your generator running, you could use all of the 20-gallon fuel and travel about 300 miles.

Note: The numbers mentioned here are just to get the point across. The above scenario did not take into account the safety mechanism that shuts down the onboard generator if the fuel level reaches a certain level. It’s usually a quarter of a tank in most RVs.

You see, your RV’s MPG remains the same, but the total distance it covers is affected by running the generator while driving.

Pro Tip: Turn off your dash air conditioner if you’re using your generator to run your rooftop AC. This will reduce fuel consumption, increase your RV’s MPG and boost the engine’s power to climb inclines.

You don’t have to worry about the fuel issue we spoke about above if you’re using a portable generator.

However, portable generators may shut down now and then. This happens when the fuel level drops and on a bumpy road, the fuel is shaking up and down, starving the engine.

To prevent this, make sure to top up the fuel before it comes down to a quarter of a tank.

04. Weather

Weather

The next important factor to keep in mind when running a generator while driving is the weather.

Generators are not designed to work in wet weather. Both rain and snow can easily damage the electronics in your generator or worse increase the risk of electrocution resulting in fatalities.

Unlike built-in generators, portable generators usually don’t come with a dedicated compartment where they sit safe from the elements. They are either mounted on a cargo carrier or sit on the back of your truck while running, exposing them directly to the elements.

What if I use a generator tent or canopy?

Well, generator tents are a great solution to run a portable generator that’s sitting stationary on the campsite. When in transit, you have shifting winds, making the canopy useless. 

Moreover, generator canopies are not designed to sustain the severe wind forces on the highway.

Therefore, my suggestion for RVers with portable generators is, avoid running them if the weather is wet. 

Alternatives Methods for Powering Appliances while Driving

Having an RV with an onboard generator can be a blessing in some cases. You have very little to worry about if you have to run it while traveling.

However, for RVers with a portable generator, you have to know a few things before running one.

But, are there any alternatives to using a generator while driving to power appliances?

Well, the answer is YES and NO.

If you have invested in solar power and have a good set of batteries then you should be able to use it to power most lighter appliances. Appliances like charging phones, watching TV, etc.

You can also use a wind generator as an alternative to a generator but not while driving. By design, wind generators have a maximum wind speed and on highways, you’re surely going above it. This will destroy the wind generator completely.

However, there is no alternative to a generator, if you want to power a rooftop AC, refrigerator, microwave, or washing machine on the road.

Conclusion

So, can you run an RV generator while driving?

Yes, you can run both an onboard and a portable generator to keep yourself comfortable even on the road.

Make sure you consider everything that we discussed in this post before running your RV generator, especially a portable unit.

Remember, whether, on the road or the campsite, a generator is the best source of on-demand power for dry camping or boondocking.