How to Use an Inverter in a Motorhome

As its name implies, a motorhome is a vehicle with adequate living space and home equipment.  So, it doubles as a vehicle and as a home. It has space for about two to eight people to sleep. Also, it has a kitchenette with cooking equipment. Many motorhomes also have a dining area where you can sit down and eat your meal.

Every motorhome has a bathroom and toilet. Indeed, a motorhome is a complete home on wheels. What a motorhome lacks is power supply.

Unfortunately, electrical appliances like the heater, television, DVD player may be of little use without power. This is why a motorhome is incomplete without electricity. Now, there are several parks with electricity where you can park your motorhome and plug it into an electricity source so that you can enjoy your electrical appliances.

What if you decide to vacation in the woods, where there’s no power? This is why you need a separate power supply. Also, when many motorhomes are plugged to the same power source in the same park, the voltage of the source will reduce. You will have to reduce your power usage.

Right now, there are two basic options of power source for you. It is either you get a generator or solar power system. We don’t recommend a generator because you need to continue buying fuel to run your generator.

If you’re frequently camp in the woods, where there’s no access to fuel, a generator will be useless. Also, generators are not eco-friendly as they make noise, and they emit gases.

Your best option is a solar power system because all you need is the sun, which is ubiquitous.  Also, the roof of motorhomes is usually wide enough to take several solar panels. Unfortunately, solar panels have a big drawback.

They generate only DC (direct current), and electrical appliances support only alternating current (AC).  A motorhome inverter will do the conversion from DC to AC for you to power your appliances and equipment. This brings us to the focus of this article. It is about using an inverter in your motorhome.

What is a Motorhome Inverter?

As a matter of fact, a motorhome inverter is a power inverter that is used in a motorhome to convert direct current to alternating current for powering electrical devices.

There is no inverter specially designed for motorhomes, as many people think. However, you have to consider the total power consumption of all the appliances in your motorhome before picking an inverter for your motorhome.

How to Use Inverter an in a Motorhome? Easy Steps

First of all, we need to make it clear to you that an inverter does not supply power. It converts DC to AC, and it also multiplies power. In other words, your inverter needs a power source.  That is the batteries. A battery is a reservoir of power.  The amount of power you store in them depends on how many they are.

Your inverter draws power from the batteries. Within a few hours, your inverter can drain a battery as it draws out a large amount of current. So, the batteries need to be charged as the inverter latches on to them. This is exactly what the solar panels do.

As long as there’s sunlight, the solar panels will continue to converter sunlight to direct current and send it to the batteries, charging them. By the time the sun goes down, the batteries will be fully charged. So, the inverter will be drawing from the power stored in the batteries.

We will advise you to cut down on your electricity usage when the sun goes down.  This will help you minimize the usage of your power till the next day when the sun comes out again. That being said, here are a few tips on how to use an inverter in a motorhome.

To use an inverter, you should know how much your appliances consume. This will make it easier for you to estimate your power usage. Also, it will help you avoid overloading it.

If you don’t know how much power each appliance consumes, you’re likely to overload it one day. To assist, we have given the estimated rate of power consumption of common appliances in a motorhome below.

  • Coffee maker – 8.3 amps
  • Converter – 8 amps
  • Electric skillet- 6 to 12 amps
  • Hairdryer – 9 to 12 amps
  • Microwave – 13 amps
  • Refrigerator – 2.8 amps
  • Roof air conditioner -13.5 amps
  • Toaster – 8 to 10 amps
  • TV – 1.5 amps
  • VCR – 2 amps

You should always charge your batteries whenever there’s sunlight. You can’t overcharge them. When they are fully charged, they will just act as a mere link between the solar panels and the inverter. The more sunlight your solar panels are able to access, the more the current they will generate.

So, we don’t advise that you park your motorhome under a tree. The tree will shade the panels, thereby reducing their access to the sun. That means less power will be generated. Also, a branch of the tree can break and drop on your solar panels, and break them.

When you notice that your inverter shuts down after a shorter period, it is an indication that one or more of your batteries is no longer fully operational.

Try and find out which one is it. Replace it immediately.  It is a good idea to switch off any appliance that you don’t need. This will help you save power.

Check your battery terminals constantly for corrosion. When you notice any corrosion, disconnect the terminal and wash it off. Otherwise, corrosion will make the battery terminal lose contact. Ensure that your inverter is in a well-ventilated location to prevent overheating.

How to Test a Motorhome Inverter?

There are several reasons to test your inverter. First of all, it is necessary to test it after purchase. This is because some inverters have been delivered defective or dead before.

So, you must test your inverter before you install it. Also, you should test it as a routine check. If it is not working well, you will detect it early and get it fixed or replaced before it damages some of your appliances.

In addition, you may have problems with your solar power system, and you need to find out what is causing the problem between faulty batteries and a damaged inverter. In that situation, your first step should be to test your inverter.

To test your inverter, you need either a multimeter or a voltmeter and a battery. Connect the battery to the inverter using a pair of battery cables. Connect the positive terminal of the battery to the positive socket in the inverter. You can’t get it wrong because both battery terminals and inverter sockets are labeled clearly.

Also, you should connect the negative terminal of the battery to the negative socket in the inverter. After that, you should switch the inverter on. Then connect a multimeter or voltmeter to the inverter and check the reading. If it is working well, it should give about 12 volts or slightly higher.

To be double sure, you can plug a simple AC electrical device like a fan to it. Power the device on. It should work perfectly. Virtually all inverters are protected from overheating, high voltage, low voltage, and short circuits.

When the voltage becomes too high, its fuse will blow. You will have to replace the fuse before the inverter begins to work again. In the case of a short circuit, the same thing will happen.

On the other hand, when the inverter gets too hot, it will indicate and shut down. Also, when the voltage gets too low, the inverter will shut down to protect your electrical system and the appliances in your motorhome.

After replacing a blown-fuse, you may power on your inverter, and it will not supply power. Also, after it shuts down because of low voltage or overheating, it may not supply electricity after powering it up. All you need is to reset the inverter. To reset it, just switch it off and wait for at least 60 seconds before switching it back on.

How to Wire a Motorhome Inverter?

There are several wiring methods. You have to choose the one that suits you the most. We tried four different methods, but we stuck to the last one because it is the most convenient one. That is exactly what we are discussing here for you.

The first thing to do is to install a 30-amp receptacle on the outside of your motorhome. Then you can now link it to the output of your motorhome inverter. This way, you will only unplug the RV from the shore power and plug it into the 30-amp outlet.

Remember that your converter and inverter should never be switched on at the same time. So, you should always switch off the converter before switching on the inverter. To avoid making the mistake of leaving your converter on while you switch on your inverter, you need to install a relay system.

A relay is an electrically operated switch. It should be installed close to the converter. Once you switch on your inverter on, the relay will automatically switch off the converter. This will give you peace of mind that you don’t have to worry about mistakenly leaving the converter on while the inverter is switched on.

To wrap up this section of the write-up, we will remind you that it is always a better idea to hire a professional to do the installation for you. This will give you peace of mind. Also, if you tamper with your inverter, the warranty on it may be voided because you are not a qualified person to handle it.

Inverter Installation Mistakes to Avoid:

We have compiled some of the mistakes that many of our readers make. Study them and avoid them.

1. Buying Solar Power System Components Gradually

We understand that a solar power system is a huge investment. That’s why some people prefer to buy the components gradually over a long period. For instance, they may buy solar panels today and buy an inverter six months after.

We don’t encourage this. Instead, it is better to save your money, and when you’re ready, you can buy all the components at the same time. If you buy the components gradually, you are likely to encounter some of the flowing problems:

  • Your inverter may be a wrong size for your panel output.
  • The panels you bought may be of different sizes, and as such, they won’t fit together.
  • Your components may not wire together because they have different connectors.
  • Some components may be missing.
  • Due to the headaches involved, even technicians charge higher for this kind of installation.
  • Warranty may have expired since it took you several years to install the parts. By then, the warranties on some of them would have expired.

These are just a few of the problems. There are many more. You may eventually have to repurchase some parts that are not usable.

2. Not Thinking of Expansion

When people are planning their power system, they usually think of now. They don’t think about the future. Your power consumption will increase in the future. Does your power system have room for easy expansion? You need to consider this now.

3. Inaccurate Estimation of Efficiency

Normally, the efficiency of your solar panels will reduce by about 0.5 to 1% every year.  That means after two decades, the efficiency of the panel will drop by 10 to 20%.

Put that into consideration, when estimating your electricity needs. Most people don’t plan for this. It becomes a double catastrophe. Their consumption keeps increasing while the efficiency of their solar panels keeps reducing.

Final Word

If you have been reading this article from the beginning, you should have learned the following:

  • How to use an inverter in a motorhome
  • How to test a motorhome inverter
  • How to wire a motorhome inverter
  • Common inverter installation mistakes to avoid