What Size Inverter Do I Need For My RV or Van Conversion?

What Size Inverter Do I Need For My RV or Van Conversion?

With so many choices on the market, it can be challenging to determine which inverter size you need for your RV or van. By the end of this short guide, you’ll know how to make an educated decision when purchasing an inverter.

What does an inverter do?

An inverter takes DC (direct current) from a battery bank, and converts it into AC (alternating current) to supply power to common household appliances (like TVs, microwaves, etc.)

Deciding which inverter is right for you only takes a few quick steps. Let’s get started!

RV inverter opened up

Overview

We’ll cover the different factors to keep in mind when choosing your inverter below. Be sure to follow along with our RV Inverter Calculator, so you can get your personalized results at the end!
 
We’ll be going over:

Taking inventory of 120V appliances in your RV or van

To determine which size inverter is right for your RV or van, we first need to take inventory of the 120v household appliances you plan to use. 

Start by making a list of each 120v appliance you plan to use off grid. Be sure to also note the wattage of each appliance.

Wanting to power a split phase 120/240v service with an inverter? Hang tight, we’ll cover this later.

Performing simultaneous load calculations

Once you’ve listed all the appliances you plan to use, the next step is deciding which appliances you might want to use simultaneously.

For example, you may want to watch TV while brewing a pot of coffee or cooking dinner in an Instant Pot and charging your laptop all at the same time. These would be considered simultaneous loads. 

So, we need to add up the wattage of each of these appliances to arrive at our Simultaneous Load Total. 

If you have a 120v (residential-style) refrigerator, be sure to include this in your simultaneous calculations as well. 

Check out our Inverter Calculator to easily determine your Simultaneous Load Total.

Consider your battery bank

Your battery bank will have specific requirements of your inverter, so at this step, we need to review a few details.

Battery bank voltage

Most inverters are designed to accommodate a specific battery voltage. At this step in your calculations (or using the RV Inverter Calculator), select the voltage of your battery bank: 12v, 24v, or 48v. 

Do you also need a battery charger?

Many inverters have built-in battery chargers. These are referred to as inverter/chargers (or hybrid inverters), and are perfect for those who also want the ability to charge their battery bank from shore power (e.g. with an RV park power post, a household outlet, etc.) or from a generator. 

When connected to shore power, 120v AC (or 230V AC, for many countries outside North America) will pass through the inverter and power all 120v loads. Further, if a surplus of power is available, any extra will go towards charging your battery bank.

Besides just having the ability to charge your batteries from these sources, inverter/chargers such as the Victron MultiPlus and Quattro series have some incredible additional features. These include “Power Assist,” or the ability to supplement (or assist) shore power with power from your battery bank to power loads that are larger than what the shore power or generator source may be able to handle alone.

Diving into the specifics of all the features for these inverter/chargers is beyond the scope of this guide. For more info, check out the datasheets and manuals for the MultiPlus and Quattro models

Up front, an inverter/charger will be a larger investment than just buying an inverter alone. This said, the cost is well justified if charging your batteries from a shore power or generator source is a requirement.

Confirming inverter voltage

When it comes to Victron inverters, you’ll find many options available for both 120v and 230v. For the most part, if you’re planning to only use your inverter in North America, be sure to use a 120v model.

Identifying 30a or 50a service

Service refers to the power that your RV or van conversion is rated to accept. Most RVs in North America are rated for either 30 amps or 50 amps.

Many smaller travel trailers, class Bs, and van conversions are rated for 30a. Larger fifth wheels and Class A coaches are typically rated for 50a.

Note: this is just a general rule of thumb. Be sure to consult your user manual if you are unsure about your RV’s service rating.

Why knowing your 30a or 50a service status matters

This is an important question, mainly for one BIG reason:

A 30a service only requires single-phase 120v, while a 50a service requires 120v/240v split-phase in order to operate at full capacity.

Notice how the 30a service has (1) main breaker, while the 50a service has a dual pole main breaker.
30a plugs
30a Service Plugs
50a plugs
50a Service Plugs

So, if you have a 30a service, you’ll be fine with a single 120v inverter. This will supply power to your main breaker.

However, if you tried to use a single 120v inverter in a 50a service (with one exception – noted below), only half of your appliances and outlets would be live. This is because it would only be providing power to one main breaker (meaning one half of your AC panel).

For a 50a service, you have (2) main breakers, so you’ll either want (2) 120v inverters configured in split-phase, or (1) MultiPlus 2×120, an inverter/charger that will deliver (2) legs of 120v to power both main breakers and provide power throughout your RV.

Do you have an onboard or portable generator?

The differentiation in this section is between inverter/chargers with (1) AC input, such as the MultiPlus, and models with (2) AC inputs, like the Quattro. While the single input MultiPlus has the ability to seamlessly transfer between shore power and inverter, the Quattro has an extra AC input and transfer switch for applications that include onboard or stationary generators. 

To keep things simple, there are really only three possibilities here. 

  1. If you have a portable generator and plug this into your shore power inlet, you’ll be just fine with a MultiPlus.
  2. If you have an onboard generator with an OEM transfer switch already in place (which will be the case for any RV with a factory-installed onboard generator), you can use the OEM transfer switch with a MultiPlus. Or, you can remove the OEM transfer switch and go for a Quattro.
  3. If you’re planning on installing an onboard generator in an RV retrofit or camper conversion, the dual AC input Quattro inverter/charger would be a great option.

Using the RV Inverter Calculator

If you made it this far, congratulations! You can now use the power of knowledge to make an educated decision in your quest to acquire an inverter. If you’re still a little unclear, or want to double check your work, we encourage you to check out our free RV Inverter CalculatorSimply answer a few questions and you’ll get a personalized recommendation for the inverter that will work best for your particular needs.

With all of the available options, choosing the right inverter can feel overwhelming at first. We hope that this guide has empowered you to better understand the considerations you’ll want to make before investing in an inverter. 

Give it a try below!

Inverter Calculator (Post)

Let's start with an inventory of your 120v appliances

How would you like to begin?
Heads up: You can select both options!

Choose from common 120v appliances

If any appliances will be operating at the same time, be sure to select "Yes, runs simultaneously."
Runs simultaneously?
Would you like to add your own custom 120v appliances as well?

Add your own 120v appliances

If any appliances will be operating at the same time, be sure to select "Yes, runs simultaneously."
Runs simultaneously?
Would you like to choose from common 120v appliances as well?

Let's get your system details

What voltage is your battery bank?
Will you be using the inverter exclusively in North America?
Do you have a 30 amp or 50 amp service? Hint: choose the plug you use for shore power.
Which type of generator will you have?

Your Results

Based on your results, you might need something outside of our standard recommendations. Please contact us or schedule a free 15-minute consultation call with our off-grid energy specialists.
We'd recommend a 12v 1200VA inverter or below.
Please be aware that the minimum recommended battery capacity with this model is 150Ah at 12v.

Phoenix 12/1200 Inverter

We'd recommend a 24v 1200VA inverter or below.
Please be aware that the minimum recommended battery capacity with this model is 60Ah at 24v.

Phoenix 24/1200 inverter

We'd recommend a 48v 1200VA inverter or below.
Please be aware that the minimum recommended battery capacity with this model is 30Ah at 48v.

Phoenix 48/250 Inverter

We'd recommend a 12v 3000VA MultiPlus-II 2x120.
Please be aware that the minimum recommended battery capacity with this model is 400Ah at 12v.

Victron Energy solar inverter charger

We'd recommend a 12v 2000VA MultiPlus.
Please be aware that the minimum recommended battery capacity with this model is 350Ah at 12v.

Victron Energy 12v 2kVA MultiPlus inverter

We'd recommend a 12v 3000VA MultiPlus.
Please be aware that the minimum recommended battery capacity with this model is 400Ah at 12v.

Victron Energy 12v 3kVA solar inverter/charger

We'd recommend a 12v 5000VA Quattro.
Please be aware that the minimum recommended battery capacity with this model is 800Ah at 12v.

Victron 12v 5000VA Quattro Inverter/Charger

We'd recommend a 24v 5000VA Quattro.
Please be aware that the minimum recommended battery capacity with this model is 400Ah at 24v.

Victron Energy solar inverter charger

We'd recommend a 48v 5000VA Quattro.
Please be aware that the minimum recommended battery capacity with this model is 200Ah at 48v.

Victron 48v 5000VA Quattro solar inverter/charger

We'd recommend a 24v 2000VA MultiPlus.
Please be aware that the minimum recommended battery capacity with this model is 200Ah at 24v.

Victron Energy 24v 2kVA MultiPlus solar inverter charger

We'd recommend a 24v 3000VA MultiPlus.
Please be aware that the minimum recommended battery capacity with this model is 200Ah at 24v.

Victron Energy 24v 3kVA solar inverter charger

We'd recommend a 48v 3000VA MultiPlus-II.
Please be aware that the minimum recommended battery capacity with this model is 100Ah at 48v.

Victron MultiPlus-II 48/3000/35-50 120V

Under 2400w? Consider a 12v system – contact us to learn more.
Under 2400w? Consider a 12v system – contact us to learn more.
Under 2400w? Consider a 12v system – contact us to learn more.
Over 2400w? Consider a 24v or 48v system – contact us to learn more.
Over 2400w? Consider a 24v or 48v system – contact us to learn more.
We'd recommend dual 24v 3000VA MultiPlus inverter/chargers, but note that this is an advanced system and we strongly recommend a consultation before purchase.
Please also be aware that the minimum recommended battery capacity for this set-up is 400Ah at 24v.
Contact us or schedule your free 15-minute consultation call with one of our off-grid energy specialists.

24v 3kVA Inverter 24v 3kVA Inverter

We'd recommend dual 24v 3000VA MultiPlus inverter/chargers, but note that this is an advanced system and we strongly recommend a consultation before purchase.
Please also be aware that the minimum recommended battery capacity for this set-up is 400Ah at 24v.
Contact us or schedule your free 15-minute consultation call with one of our off-grid energy specialists.

24v 3kVA Inverter 24v 3kVA Inverter

We'd recommend dual 48v 3000VA MultiPlus-II inverter/chargers, but note that this is an advanced system and we strongly recommend a consultation before purchase.
Please also be aware that the minimum recommended battery capacity for this set-up is 200Ah at 48v.
Contact us or schedule your free 15-minute consultation call with one of our off-grid energy specialists.

Victron MultiPlus-II 48/3000/35-50 120VVictron MultiPlus-II 48/3000/35-50 120V

We'd recommend dual 48v 3000VA MultiPlus-II inverter/chargers, but note that this is an advanced system and we strongly recommend a consultation before purchase.
Please also be aware that the minimum recommended battery capacity for this set-up is 200Ah at 48v.
Contact us or schedule your free 15-minute consultation call with one of our off-grid energy specialists.

Victron MultiPlus-II 48/3000/35-50 120VVictron MultiPlus-II 48/3000/35-50 120V

Save your calculations

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Which inverter will you be using for your project? Why did you choose that inverter? We want to hear from you!

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