RV Inverter: The Ultimate Guide to RV Inverters

Modern RVs come equipped with many appliances that make them feel like home. However, their electrical systems are very different from your home. Portable electrical systems have different equipment needs. An inverter is a valuable piece of mobile electrical systems that you may not be familiar with.

In this ultimate beginner’s guide, we’ll explain RV inverters in everyday terms. Keep reading for everything you need to know to buy, install, and maintain your RV inverter.


What Does An RV Inverter Do?

An inverter provides your RV power when you aren’t hooked up to an external power source or “shore power.” It does this by turning DC (direct current) from the batteries into AC (alternating current). Alternating current is what appliances and outlets run on. This means you can still use electricity if you are camping in remote locations off the grid.

Depending on its configuration, size, and power output, an inverter can serve all the outlets in your RV or only a few. Many new high and mid-end model RVs come equipped with an inverter. If you have an older or a budget RV, there is a chance that you don’t already have one.

How Can I Tell If I Already Have An RV Inverter?

It’s pretty easy to figure out if you have an inverter. If any of your outlets or appliances work when you aren’t connected to shore power or a generator, then you have one. The electricity you have is being pulled from your RV batteries by the inverter.

RV Inverters Explained

So, how exactly does an RV inverter work?

The inverter takes the direct current power coming from the RVs battery and converts it to alternating current. The 12V batteries in your RV are inverted into 120VAC. This AC is the only current that will power your outlets and appliances.

To invert 12v to 120VAC, it requires a 10X increase in output. The laws of physics dictate that there then also has to be a 10X increase in input. The more output you need, the more amperage you will need to pull from the batteries.

As an example, a 1700 watt microwave needs 14 amps to work. To power the microwave, the inverter would need to pull at least 140 amps from the battery.

On top of the smallest amperage needed, inverters typically only run at 90% efficiency. This means that there is a 10% loss in power during inversion. Due to the efficiency gap, the inverter has to pull an extra 10% amperage from the battery. In the above example, the inverter needs to draw at least 154 amps from the batteries to power the microwave.

Large inverters can create significant power. However, their capacity can’t exceed the battery’s amperage. An average RV battery can supply around 50-70 amps per hour. Limited battery amperage makes it challenging to provide enough power for high-watt appliances.

The answer to this dilemma can be a more powerful power bank, but added battery power can be expensive and heavy. There are limits to how much you can power with an inverter system. In most situations with a limited budget, the average RVer can’t power everything.

How To Select An RV Inverter? Things to Consider:

An inverter can provide you with a lot of added convenience while on the road. You create a system with enough power to charge your phone and use essential appliances. If you have an unlimited budget and timeline, you could also set-up off-grid power for all your outlets.

If you are thinking about installing an RV inverter, it’s crucial to pre-plan. Inverter set-ups can vary widely depending on several factors. It’s essential to think through your power needs and the optimal rewiring plan. Make sure to do this before moving forward on purchase and installation.


 Rewiring Needs

The rewiring is the first factor to consider in your inverter installation plan. Obviously, the wiring is how the power will get from the inverter to your outlets and appliances. What you may not realize is that the layout of your RV can dictate how much rewiring you need.

What if the bedroom outlet and kitchen appliances you want to power are on opposite sides of your RV? This can require a lot of wiring to make this happen. Another option is to get more than one inverter and install them in different locations.

As you can see, your power needs will have an effect on your wiring needs. Let’s review that in detail next.

Power Needs

Unless you have unlimited money, space, and time, chances are you have to make decisions on what you want to power. At the very least, you can power a couple of outlets. Two outlets might be enough to charge portable electronics and some small appliances. If your cell phone and mini-fridge are your must-haves, you’ll be in good shape.

There is also a range between powering it all and the bare minimum. Review different options that fit into your budget and timeline. From there, you can choose the optimal set-up for your needs.

Decision Guide: Choose The Right Inverter for Your RV

Once you land on what you want to power and how to wire the system, your next step is to shop for an inverter. There are three significant ways that inverters vary from one another.

  • Standalone vs. Integrated
  • Watt Output
  • Wave Type: Pure Sine, Modified Sine, or Square Sine

Let’s review and compare the options for each in detail.

Standalone vs. Integrated Inverters

An integrated inverter is sometimes called an inverter charger. An integrated system is a converter (charger), transfer switch, and inverter all in one. You get more functionality from an integrated model, but with a higher price tag.

Despite the higher cost, an integrated inverter is ideal if you want to replace or add any part of your system. For example, replacing an old converter or adding an automatic transfer switch. It’s much less complicated to install one system rather than each piece separately.

A standalone model only includes the inverter. This type is ideal if you already have an updated system with enough charging and battery bank power. You will save money by only buying a single component. It’s also less expensive to maintain a standalone inverter. You won’t need to repair all three parts if something goes wrong.

Watt/Amp Output

The output is the power an inverter provides with no bottleneck in battery capacity. The higher the output, the higher the price tag. You’ll want to carefully consider how much power capacity you need so you don’t overpay for unused capacity.

You’ll find output expressed in both watts and amps. Let’s review the basics of electrical output.

Amps X Volts = Watts

Using the information an appliance, you can calculate the watts you need to power it. Say you have a machine that’s 12A @ 120V. Multiply these two numbers together to get the wattage.

12 Amps X 120 Volts = 1440 Watts

To get an estimate of the output you need, add up the wattage for all the appliances you want to run at once. If you are looking to power an outlet rather than an appliance, note that the average output of an outlet is 1800 Watts.

There are two types of output capacity: peak vs. sustained.

Peak output is the maximum wattage the system can provide in a short burst. This is always higher than the sustained capacity. Think of it like a sprinting speed. Sprinters can hit breakneck speeds but only for a short amount of time. Depending on the model, an inverter can hold peak capacity anywhere from seconds to a few minutes. This is helpful for appliances like refrigerators that need a lot of power when starting up.

The sustained output is how much power the inverter provides during regular use. Steady output typically refers to usage over multiple hours. On average, most RVers find that 1000-2000 watt output covers their daily needs.

There are a lot of inverters on the market between the 1000W-2000W range. If you don’t routinely use that much, you can find options as low as 120W. You will notice a big price range in inverters of the same wattage. This is because of the wave type is one of the biggest drivers in inverter cost.

Wave Type

Inverters convert direct current to alternating current using one of three wave types. Different wave types that affect how smooth the transition is. The wave-type matters because it affects how your inverter works with your appliances.

Pure sine inverters: This inverter type is superior and is also the most expensive. Pure sine offers the smoothest transition. It produces power in line with native AC or the kind of electricity you get from shore power. It works seamlessly with all appliances and merits the higher price tag.

Modified sine inverter: These inverters have a pause built-in when converting DC to AC. This pause can make them incompatible with certain appliances. Modified sine inverters can even cause damage. It depends on the devices and the inverter model, so research is critical before you buy one.

Square sine inverters: Square sine has the most abrupt change in current. As a result, these inverters are the least expensive. They do not work well in RVs and tend to damage appliances. If you have a used RV with a square sine inverter, replace it with one of the other two wave types.

You can save money on a modified sine inverter. But the gap between pure sine and modified sine has been narrowing as RV technology advances. The cost of a pure sine inverter has decreased in relation to the other models. If possible, check if you can live with a lower output to fit a pure sine inverter into your budget.

Installing Your RV Inverter

Now that you have done your pre-planning and chosen the perfect inverter for your needs, it’s time to install it. Inverter installation can be simple, depending on your knowledge of electrical systems. We’ll cover installation non-negotiables as well as a quick installation guide.

RV Inverter Installation Non-Negotiables

Inverter Power and Shore Power can’t both go to an outlet at the time. This is incredibly serious because if this happens. Your RV could suffer an electrical fire or severe damage. Installing an ATS (automatic transfer switch) will avoid this. An ATS detects power from different sources and will automatically switch to shore power when you connect.

The converter/charger should never receive power from the inverter. The converter is what charges the battery when you connect to shore power. You only need to worry about this when installing a standalone inverter. An integrated model is pre-configured with the wiring between the converter and inverter.

Step To Install An RV Inverter

Installing an inverter is at it’s most basic a two-step process.

First, you have to connect the inverter to the RV batteries. The inverter connects to the battery using large wires. This makes this side of the installation pretty simple.

Next, the inverter needs to connect to the outlets it will power. On this step, you have to choose between using existing outlets or installing new ones. This will affect how complicated the installation is.

To connect the inverter to existing outlets, you first need to disconnect those outlets from the existing circuit breaker. Then you can wire the existing outlets to the inverter.

If you want to use the outlets both on inverter power and shore power, you need to install an ATS system. To do this, you will wire your inverter to a unique power panel and connect it to the main breaker with the ATS. This will automatically switch to shore power and inverter power when needed.

You also have the option of installing new outlets that are only powered by your inverter. This makes for a more straightforward installation but can lead to clunkier use. You can use an extension cord to connect your appliances to the new outlets when you aren’t on shore power.

Should I Install My RV Inverter Myself Or Hire a Professional?

If your RV installation requires a lot of rewiring, it can be difficult. RVs are small spaces with thin walls and complicated configurations. If you have little experience with electrical systems, it’s best to hire a professional.

Hiring an electrician will cost more than self-installation, but it’s often worth it. Electrical systems can be deadly for novices. Work this cost into your project estimates early to stay in budget. Make sure the person you hire is an expert in both electrical systems and RVs.

RV Inverter Reliability & Maintenance

Today’s RV inverters are sturdy and don’t wear out easily. Inverters are more susceptible to damage than system failure. Be aware that both heat and moisture can compromise your inverter. To prevent damage, use a fan system to keep the inverter cool and dry.

Acid fumes from batteries will also damage your RV inverter. Use sealed batteries or mount the inverter away from cells so they won’t come in contact with any leaks.

If you avoid these common causes of damage, your inverter should run reliably for years to come.

Are There Alternatives to RV Inverters?

Yes, there are other ways to get electric power in your RV when you aren’t hooked up to shore power.

The most common alternative to using your battery power is using a generator. Generators use fuel to create electrical energy for your RV. Generators can be portable or built-in. The more power output a generator provides, the larger and noisier it tends to be.

Solar and wind power are often thought to be alternatives to RV inverters. In reality, they aren’t. These power sources use panels or turbines to create DC power that can charge batteries. As covered, DC power cannot be directly leveraged to power appliances. To use either wind or solar power for outlets, you still need an inverter.

Wrap Up

If you have any questions or want to share your experience about RV inverters leave a comment blow and I will respond to it.

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