What is an Inverter in an RV and Why Do You Need it?

Recreational vehicles, or as they’re better known, RVs, are large vehicles or trailers that provide a home away from home for adventure seekers and travelers. Since it is designed to be used both in the wilderness away from the electrical grid and on electrical grid power, it needs to use an inverter and converter to function properly.

What is an inverter in an RV? An Inverter is a device that converts direct current (DC) power to alternating current (AC) power and increases the voltage. An RV’s battery supplies DC power, but most household appliances that are found in an RV use AC current. An inverter allows you to run the appliances in an RV off the on-board battery.

There’s a lot that goes into supplying power to an RV since the U.S. electrical grid supplies AC power, and that’s the power that the majority of household appliances uses.

Car batteries, however, supply DC power, so if you’re in a situation where you need to run household appliances in your RV (like a microwave or stove), you’ll need an inverter.

What Is an Inverter and Why Do You Need it in an RV?

Without getting too much into the physics of how electricity works, there are two types of electricity: direct current and alternating current. In direct current (DC), the electrical current flows in only one direction.

This type of current is common in batteries, like those found in cars. Car batteries, and those found in RV’s, have a power output of 12V.

Alternating current, on the other hand, has an electrical current flowing in two directions. This is what’s supplied by an electrical power grid; i.e. the sockets you plug things into in your house.

In the U.S., that alternating current usually has a power output of 120V, which coincidentally happens to be the voltage most household appliances requires.

An RV has a lot of devices like microwaves, stoves, air conditioning, the electrical outlets, and fridges, all of which require 120V, AC power.

When your RV is parked at a spot where you can plug it into regular power (called shore power), that’s not an issue, but if you’re in a spot where you need to run your appliances off the on-board battery, you’ll need an inverter to make it work.

Most of the lights in your RV, however, use the DC power supplied by your battery, so you won’t need an inverter to power those. This includes the TVs that come standard on RVs, as well as the radio and water pump.

However, you’ll want an inverter just in case you’re ever in a jam and need to run appliances off your battery.

Types of RV Inverters

If you want to be able to run all of your appliances off your battery (more on why running them all at the same time is a bad idea later), you’ll want to buy a pure sine wave inverter, since they put out power that’s exactly the same as the AC power you’ll find in a house.

The other two types, square wave inverters and modified wave inverters, can damage certain devices.

When you’re picking an RV inverter, you’ll need to pay attention to the wattage it supplies. This tells you how much power the inverter is capable of putting out, and you won’t be able to exceed that.

For instance, let’s say you have the following devices that you want to be able to power off your RV’s battery:

Refrigerator: 150 watts
Microwave: 600 watts
Air conditioning: 600 watts
Outlets: Varies (depending on what’s plugged into them)

If this is the case, you’ll want to get an inverter that’s capable of putting out at least 1350 watts; just add up the wattage requirements.

If you exceed that wattage with all your devices, the inverter might just power off, it won’t power certain things, or it could be overloaded and be damaged after a period of time in that state.

Taking Care of Your RV Batteries

If you’re planning on using an inverter to power anything in your RV, you should have a basic understanding of how to take care of your batteries so you’re not making costly repairs.

Your inverter will be running off these batteries so it’s important to understand how to maximize their life.

Your RV has two different types of batteries; the battery required to start the RV’s engine, and the batteries used to power the stuff on board. The latter type of batteries are often referred to as “house batteries” that are specifically designed to be discharged and recharged constantly.

You shouldn’t use starter batteries for this application, as constantly discharging them and recharging them can damage them to the point of non-use.

If you’ve ever had a dead car battery, you know you can only jump it so many times before it won’t start again.

The main thing to look out for with RV house batteries is undercharging or overcharging. Either of these done many times can cause significant issues and will seriously shorten the life of your batteries.

Other concerns and care tips are dependent on the specific type of battery you purchase.

Picking an Inverter for Your RV

If you’re planning on using your battery for any power in your RV, you’ll want to get an inverter. They’re cheap enough that it’s nice to have them on hand in case you need it, and they’re simple to install and get working as well.

How to Select the Best Inverter for an RV >> Check out the video below:

There are a few factors you should consider when picking out an inverter for your RV:

Price
Wattage
Size
Outlets
Ease of Installation
Safety Features

Price

In general, the higher the wattage output, the more expensive the inverter. The pure sine wave inverters that can power all devices and appliances are also the most expensive.

Determine how much you can spend on an inverter and get one that meets all your power needs, plus gives you a little room for expansion if necessary.

Wattage

As briefly described above, wattage refers to how many devices you can successfully power off your inverter. Most inverters come in various wattages, ranging from a few hundred watts to 8,000.

Higher wattage devices will be more expensive and they also may be physically larger.

Size

RV’s are limited on size, so the size of your inverter is an important consideration. As technology improves, things get smaller, but you should know where your inverter needs to go and get one that will fit that space.

Outlets

Some inverters have a few outlets right on the device; that may or not be important to you, but it’s a consideration. An inverter with a couple AC outlets and maybe a USB outlet or two might come in handy.

Ease of Installation

Unless you want to pay a pro, you should check online reviews to make sure your inverter is easy to install yourself. Most come with instruction manuals so you might be able to figure it, and there might be online videos to reference as well.

Safety Features

Many inverters have a variety of safety features to be aware of as well. Some of these include overload protection, cooling fans, over- or under-voltage alarms, surge protection, and short-circuit prevention.

Closing Thoughts

Most RV owners will find a need for an inverter at some point. Having an inverter and good on-board batteries gives you the option to park away from the grid, which is probably part of the reason you got an RV in the first place.

Inverters are usually simple and easy to install, but make sure you understand the power requirements you need before you go purchase one.

Frequently Asked Questions

Here are a few common questions people often have about RV Inverter:

What Is The Difference Between an RV Inverter and Converter?

What is the difference between an RV Inverter and an Converter? An inverter turns DC Voltage to AC Voltage, while a converter turns AC Voltage into DC Voltage. As you can tell, they both transform voltage; they just do it in opposite ways.

Basically, they are just the inverse of each other.

Some people believe that you must have both in your RV but that is not the case. Your DC system will run most of the lights, water pumps, circuit boards, and other appliances with no issue. You can go without any AC Voltage for at least 6 days before you start to use up your DC Voltage.

However, it should be noted that you will need AC Voltage for a TV and air conditioning unit if you have one. But this isn’t a necessity for everyone. It depends on your priorities!

Should I Leave My RV Inverter On All The Time?

There are two different schools of thought on this topic. To tell you the truth, there are reasons for leaving it on and for leaving it off. I’ll take a look at both sides of the story.

Reasons For Leaving Your Inverter On:

You’re driving, in which case you need to leave it on to use all your AC appliances.
You’ve just disconnected from a campground’s electricity supply.
If you believe you’re going to lose shore power but still need your devices, you’ll have to leave it on.
If you have a fridge running from it, you’ll need to leave it on all the time. Otherwise, you’ll spoil your food.
You won’t lose any alarm clock settings by turning it off.
You can always charge your devices.

Reasons For Leaving Your Inverter Off:

The manufacturer’s manual advises you to turn it off when not in use.
It saves battery. Sometimes, inverters pull more than 10 times as many amps off the battery than it needs.
You’ll save a lot of wear and tear damage.
You will save loads of energy by turning it off if you don’t have AC appliances that need constant power.

Will a 1000 Watt Inverter Run a Refrigerator?

Will a 1000 Watt Inverter run a refrigerator? Yes, 1000 Watt inverter will be more than powerful enough to run a refrigerator. It is more pressing that you know the start-up power required to actually start your fridge’s compressor. Once it has kicked in, it should only need roughly 300 Watts to run.

Theoretically, a 1000 Watt inverter should be able to kick out 2000 Watts for a short time which will be enough to get your refrigerator going. However, just ensure your inverter can handle that before you begin setting up your fridge.

Having said all of this, you have to be careful that your inverter doesn’t reach its alarm state. If it does, it will switch off which could cause your fridge to heat and spoil your food.

It will make a beeping sound if this does happen. So, as long as you’re around to hear it, nothing catastrophic should occur.

Yours might not do that, but I are going to assume that it will since it’s a safety mechanism. You will need to manually reset the inverter promptly to stop your food from being destroyed by excessive heat.

Overall though, you should be absolutely fine to run your refrigerator with a 1000 Watt inverter. Just keep an ear out for that pesky alarm!

What Would Cause an Inverter to Trip?

There are numerous reasons why your inverter would trip (unfortunately). While I can’t go through every single one as I’d be here forever, I’ll tell you about the 4 most common reasons for inverter trips:

1. Electricity Grid Failure

If the surrounding area is experiencing a power cut or your inverter’s regulator or earth leakage switch is turned off, it won’t be acquiring electricity from anywhere. It then shuts down on its own to protect you and your family.

Your inverter is always measuring the voltage and frequency from the grid and will alter its generated power based on this. So, if it shuts down for a power outage, it’s an automatic safety function.

2. High Voltage

If you’re noticing that your inverter trips multiple times each day, then the voltage in the outlet is probably too high. Again, it will shut down for safety reasons.

The voltage is too high because of one or more of the following:

The voltage in the residence is more than 240V
The connection cable is too thin
The inverter is plugged into the phase with the highest voltage

3. Not Enough Sunshine

The solar panels connected to your inverter only generate power when the sun is out. If it goes behind clouds, there’s snow on the panels, or it’s sunset, you won’t be receiving any electricity because the light has disappeared. Once the sun comes back out, you’ll acquire power automatically.

Of course, this won’t really affect you during the summer months but when winter rolls around it can get pretty frustrating.

4. Inverter Failure

If the PV-system fails, you’ll receive an error message from the inverter. You’ll be able to read said message on the screen and, as long as you have the manual, you can figure out what it’s trying to tell you.

How Many Batteries Do I Need For a 2000 Watt Inverter?

Unfortunately, I can’t really give you a solid answer to this because I need to know how many continuous hours of run time you require.

How many batteries do I need for a 2000 watt inverter? With a 200 amp 12-volt battery you can run a 2000 watt inverter for 1.2 hours. So depending on how long you are planning to run the inverter you need to choose the batterie accordingly.

You can find the calculation below and then I’ll give you an example to help you out.

The calculation is as follows:

Hours needed (continuously) x watts = total watts / DC volts = amps needed

So, let’s have a look at an example to help you figure it out for yourself. Ready?

Example Time

You have a 2000 Watt inverter 12 Volt, right? If you push your inverter to its limits, you are taking 2000 Watts divided by 12 Volts every hour. In other words, you’re pulling 166.6 DC amps each hour.

So, if you purchase a 200 amp 12-volt battery, you would get 1.2 hours of run time. How did I work this out? You divide 200 amps by the 166.6 amps that I figured out earlier.

Although, you should bear in mind that this would fully drain the battery. I do not suggest you do this as you’ll end up causing damage to your equipment. I recommend only a 50% discharge depth.

To work this out, you would need to divide the 1.2 hours by 50% to get 0.6 hours. Likewise, if you want a 30% depth of discharge, you would divide 1.2 hours by 30% to get 0.36 hours.

How Long Will a 12v Battery Last With an Inverter?

Inverters will convert your 12V DC battery into a 230V AC output. This is important so you can do the calculations I’re about to show you.

Firstly, you need to know your “total power” figure. To do this, you need to find out how much power each device will use. If you have the number of Watts that will be used by the appliances, then just add the numbers to get your total power figure.

Then, divide the aforementioned total power value by 10 to get the number of amps when you’re running everything off a 12V battery.

Now for the part that you’ve been anxiously waiting for!

Find out your battery’s Ahr (number of Amp-hours) and divide this by the number of amps taken from the battery. This value you end up with is how long the battery will last when fully charged.

If you don’t feel like doing the calculations right now (I don’t blame you!) just take a look at our handy table below to know how long your 12v battery will last with an inverter:

Power Taken (Watts)	80 Ahr Battery Run Time (Hours)	115 Ahr Battery Run Time (Hours)
30	29	41
50	17.4	25
80	10.8	15.5
100	8.6	12.4
120	7.2	10.4
150	5.75	8.3
200	4.3	6.2
250	3.5	5
300	2.9	4.1
500	1.72	2.5
1000	50 minutes	1 hour 15 minutes

Can I Run a Heater Off an Inverter?

You will find that heaters tend to have an insanely heavy electrical load. However, don’t let this put you off (necessarily). Make sure your inverter’s output rating is large enough to support the power required by the heater.

Can I run a heater off an inverter? Yes, you can do it. However, a standard room heater will pull roughly 10 amps from your inverter. Assuming, that your inverter has an efficiency rating of around 95%, you’d need over 105 amps from a 12V battery which will drain it in under an hour.

That is not really what you want!

The moral of the story? Purchase heaters that your inverter can tolerate. Alternatively, buy an inverter that can cope with your heater. Whichever way round you decide to do it, ensure you aren’t going to break your whole set up!