Why Do You Need an Inverter In an RV

The units in the motorhome operate on either direct current (DC) or alternating current (AC). With direct current, the current flows in one direction, resulting in a constant supply voltage, whereas with alternating current it changes direction periodically.

Direct current for the RV is provided by the batteries in the house, while alternating current is provided by an electrical outlet or generator. Another AC power source may be an inverter that converts a DC power source from a battery to a 120 V AC power source.

Batteries in a motorhome can be connected in parallel or in series, and depending on the voltage and number of batteries connected, you will have either 6V, 12V or 24V. The alternating current is 120 volts, which is needed for large aircraft.

So what is the role of the inverter in the RV when you have other power options as well?

Why you need an inverter in a motorhome

The RV inverter takes 12 VDC from the house battery and converts it to 120 VAC. If shore power or a generator is not available, it can be used to power camping gear that runs on 120V AC.

A recreational vehicle, like your home, is equipped with many appliances that require 120 volts to operate, except for appliances that require 12 volts DC.

Large appliances such as television, microwave, hair dryer, air conditioning require 120 volts. Smaller devices such as a roof fan, carbon monoxide detectors operate on 12 V direct current.

Some equipment is supplied with 120 V AC, for example. B. a laptop, are sensitive and require a pure sine wave to operate, otherwise they may be damaged.

Depending on the power generated by the inverter, they can be classified as pure sinusoids or modified sinusoids. We’ll talk about that later in this article.

An inverter can power just about anything that a shore power system or generator can power. The only plug, of course, is the size of the inverter.

As you know, appliances make noise with watts. Actual assets may be greater than business assets. For example, an air conditioner may require 1,200 watts to operate and 1,800 watts to start.

The camper’s inverter can power any of the following devices, provided it is rated for the required power.

  • Air conditioner
  • Television
  • Microwave
  • Hairdryer
  • Notebook
  • Water pump

These are just a few examples. It can power almost any device that uses AC power.

The total power required by the devices operating simultaneously must not exceed the power of the inverter. It can be z. For example, you may be using both AC and microwave power and the total power exceeds the capacity of the inverter, in which case the system will blow the fuse.

This whole power thing can be confusing. This will be discussed in more detail later in this article.

But before we do that, let’s look at the schematic, configuration and location of the converter. We’ve seen the basics, now let’s focus on installation in your RV’s electrical system.


Simply put: An inverter generates a voltage similar to shore power by using the energy stored in your home battery. Consider the configuration in the diagram below.

You can see here that the battery in the motorhome produces 12 volts, which is not suitable for the operation of large appliances such as a TV or microwave. The inverter takes 12 VDC and processes this to produce 120 VDC at the output.

The power of 120 volts can be used in larger devices such as. for example, a TV set or a hair dryer. The output of the inverter can be a pure sine wave or a square wave, also called a modified wave.

The inverter can power just about anything you need in an RV, even a 120-volt air conditioner. Starting and operating the air conditioner requires the most power compared to other appliances in the RV.

A hair dryer or microwave also require high power, but they only work for short periods of time. AC power consumption can last for 5 to 8 hours at a time, so AC power consumption is an important factor.

For the motorhome, the inverter is available in different sizes, from 400W to 300W and more. The size you need depends on the power consumption of all the appliances running in parallel in the motorhome.

Here is a detailed wiring diagram that shows how the inverter fits into the picture of an electrical system for an RV.

Recreational Vehicle Electrical Wiring Diagram

The DC battery can be charged by the engine alternator to provide 12 V DC. The battery can also be charged with a solar panel kit or a generator. The inverter can also be used to charge the battery when not in use.

This chart is always at a high level, as are many other elements that come into play. Here, the switch is the z. B. not available. It is an important part of an inverter.

The TS (switch) essentially acts as a switch between the inverter and the shore power system/generator. If we have shore power, no inverter is needed, and this switch does the same. It connects one of them, depending on the availability of coastal energy. If there is no shore power, an inverter is connected to provide 120 VAC power.

The switch can be automatic or manual. With the manual setting you have to set it to the correct power source, and with the automatic setting it automatically switches from shore power to the inverter if it is not available.

The installation of the inverter is very easy and only takes a moment. Once the inverter is plugged in, you have an automatic switch or a manual switch that powers the inverter when shore power is not available.

Compared to a generator

The difference between a generator and an inverter is the source used to provide AC power. While the inverter operates on DC power, the generator requires fuel (gasoline, diesel or propane) to produce 120 VAC.

Because the generator burns fuel, which causes noise during operation. This also requires a special commissioning procedure. With most generators, this will not happen by simply flipping a switch. You have to pull the winding cord and sometimes you have to try several times before it starts.

The inverter does not generate any sound other than alarm signals which may be caused by malfunctions or problems. Switching the power supply to the inverter is also facilitated by a switch, which may be manual or automatic.

Do you really need it?

If you frequently visit recreational vehicle campgrounds without a power outlet or large generator, but still want the luxury of 120-volt power for large appliances, you may want to invest in an inverter. An inverter can also be useful in an emergency if you are stuck in a place where only a DC battery is used as a power source.

It is always better to have an inverter if you are not sure if you can get shore power or not. Especially when you’re on the go, an inverter can provide the power you need for your major appliances.

There are many other applications where the inverter can help you avoid unforeseen situations. Let’s look at some of these scenarios.

No shore power and no generator

The inverter can only use the battery to provide 120VAC. Without connection to a land power cable or generator, an inverter may be more economical for you.

Some campgrounds don’t have shore power, and if you’re in one of these locations, an inverter can be a great eco-friendly way to power your devices.

Restrictions for generators

Having a generator is really great. Before using an inverter, make sure you have a generator. However, there are certain limitations with respect to generators.


First, the generator is noisy, and you don’t want to use it all the time. If you z. B. you need to charge your computer or work with your TV for a while, you may not want to run the noise generator. The inverter is easy to use and also less tiring.


Second, your generator may run out of fuel. The built-in generators use the fuel from the motorhome and once it reaches 1/4 of the level, the power to the generator is cut off.

Moreover, the generators consume a lot of fuel. In any case, an inverter only makes sense in combination with a battery as a power source.

Transport problems

Transporting the generator can also be a problem. If you have a folding trailer, you will need to mount the generator securely, probably above the propane tanks. They are heavier, need more space and require special fasteners. The inverter, on the other hand, is small and compact, like a little box. This makes them very easy to use and transport.

Camping hours

Some campgrounds have restrictions on how long generators can run. This is done for several reasons, including B. to reduce noise levels, reduce emissions, and also to cause less nuisance to your neighbors.

However, this may not be good for you if the campsite does not have access to the shoreline. You have to return from the tourist site to the campsite to use the generator. Only if you don’t have an inverter.

If you have no other choice.

It can happen to anyone. Unexpected things happen when things don’t go as planned.

Bad weather, unplanned visits or problems with certain places can leave you stranded in a place where you have no other source of power. At such times, an inverter can be very useful.

Dry camping or bungalows in a remote location are not always what you expect. A night without generator fuel or other generator problems can leave you without power if you don’t have an inverter with you.

The inverter is already installed in the camper.

Some motorhomes are already equipped with an inverter, so you don’t need to install another one. Many vans are equipped with it as an option.

If you have bought a used motorhome and want to know whether it is equipped with an inverter or not, just consult the manual. See the RV manual for more details on the inverter. You can also ask the previous owner to confirm this to you at any time.

If you want to try it out yourself, turn off the engine and shore power and try to operate devices such as radio or television; they should work when the inverter is installed, otherwise they won’t start.

Decide on the amount

So you are convinced that an inverter can be a good investment, and you are now ready to purchase one for your recreational vehicle. But before you make a decision, you should pay attention to the size, i.e. the power.

The inverter is designed for the energy it can produce. So let’s see what the ideal size inverter is for your RV.

The size of the inverter you should buy for your RV depends on the number of watts needed to run the appliances at the same time. In practice, you should go at least 10 to 20% higher than the total power you need.

If you want to use an inverter as an emergency power source, choose an inverter that can accommodate all the devices you will need in an emergency. You can get an inverter from 400W to over 3000W.

How many watts do you need for the devices in your van? This is simply the total power required for all devices that will work in parallel. There may be air conditioning that works in conjunction with the refrigerator and other appliances.

Each of these devices has a capacity for operation and exploitation. The starting power is usually higher than the operating power. Here are some examples of average wattage consumption to give you an idea.

  • Microwave: 600-700 W
  • Refrigerator: 500 W
  • TV: 50-80 W
  • Light: Based on watts (20-100 watts)
  • Mobile Charging : 20W
  • Laptop computer: 100-120 W
  • DVD: 30W

The wattage depends on several factors, so the total consumption may also vary. So you need to do a test to find out how many watts can be total. Based on this, you need to decide how much power the inverter will have.

For example, their consumption may be 1200 watts. In this case, don’t calculate with 1200 watts, but with 1500 watts or more to be sure.

Battery size

Using the converter alone is not enough to accomplish the task. The key point here is the power source, which is a DC battery. If you need to run devices for long periods of time, or if you want to run large devices that consume a lot of power, your batteries need to be big enough too.

If you want to use a larger inverter, you need to increase the size of the battery bank. The inverter can discharge the batteries if the devices consume a lot of power. Check how long the battery lasts in inverter mode here.

Inverter type

Before buying an inverter, it is very important to know the different types. Otherwise, you may end up buying a completely useless device for your RV.

There are two types of inverters: the first is a pure sine wave inverter and the second is a modified wave inverter.

The main difference between the two is that they produce an output wave. The pure sine wave tries to replicate what you get from the coastal energy. The smooth sine wave is particularly suitable for sensitive equipment such as laptops or televisions.

Since they produce a pure sine wave, they are also expensive. If you want to use LED or CFL lamps, make sure you only use a sine wave inverter.

The output of the modified waveform converter is not a pure sine wave, but is generated by a multi-stage which is not suitable for sensitive equipment.

Inverters of this type are inexpensive, so caution should be taken when choosing an inverter. Don’t buy an inverter with a custom shaft just because it’s cheap. If you do, expensive equipment can be damaged. These converters can be used to operate devices that work without problems with this modified power supply.

Pure sine wave inverters are becoming more affordable as technology advances.


The cost of RV inverter depends on the power consumption. You can buy a 1000 to 2000 watt inverter for $200 to $450. The higher the power, the higher the price.

Other issues

Should I leave the inverter on all the time?

If you leave the inverter on all the time, the power supply will be maintained even if the shore power fails. The batteries in your motorhome discharge to a certain level and then recharge.

Does the inverter consume energy even when the devices are not working?

Like most devices, the inverter consumes some power even when no device is connected to a power source. However, this consumption is low and should not bother you too much. In addition, the batteries recharge when they fall below a certain level.


An inverter is definitely a good investment for your recreational vehicle, especially if you travel a lot or work full time. It is the perfect complement to your other energy sources, such as the generator, battery and solar sets.

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