Converter, Inverter, & Inverter Charger: What's the Difference and Which Do I Need?
Do you want to boondock off-grid AND run your higher wattage appliances like you can at a campsite with electrical hook-ups? This is where installing an inverter in your RV can be a game changer!
If you are new to RV electrical systems, let’s talk about different types of power and their respective sources. Most RV electrical systems run on two different types of power – AC and DC.
Alternating Current (AC) runs 120V household appliances that are plugged into outlets in your RV. This power typically comes from a “shore power” hookup – an external power source that is connected to the electrical grid. When you pull into a campsite with electrical service and plug the RV into it, the fridge and all of your electrical outlets will run just like at home.
Direct Current (DC) runs your 12V - 48V appliances and charges your batteries through a converter when plugged into shore power, or simply from the RV battery bank while off-grid. This allows you to power your lights, vent fans, radio, slide out motor, power awnings, USB outlets, and other devices.
And, if you want to run both AC and DC appliances while off-grid, you’ll need a battery inverter or inverter charger. So, what’s the difference?
Converter vs. Battery Inverter vs. Inverter Charger
When buying a new RV or converting your rig to be able to run off-grid on solar, understanding this terminology is key.
Converter: Most RV manufacturers install a “converter” into the RV’s electrical system so that your RV house battery bank will charge while you are plugged into shore power – it converts AC power to DC power so that when you leave the campsite (or home), your battery bank is topped off and ready to keep things going until you plug in again.
Battery Inverter: An inverter does the opposite of a converter; it transfers the DC power from your battery to AC power so that you can run AC appliances when you are not plugged into “shore power.” Most RV manufacturers do not include an inverter into the factory electrical system – unless designed as an off-grid or overlanding rig. See our recent blog for details about what to look for if you are shopping for an RV with pre-installed solar components.
Inverter Charger: This device is a combination of a converter and inverter in one unit. Inverter chargers can change AC to DC power to charge your battery bank AND change DC to AC, so you can run household appliances while off-grid. In fact, they can do both at the same time. These devices have an automatic transfer switch, so that when you plug into shore power it automatically switches over, allowing 120V power to “pass through” the device to all the AC electrical circuits. At the same time it takes some of the AC power, changes it to DC power, and charges the house batteries.
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Which of These Devices Do You Need for Your RV?
While there are many things to consider when deciding which inverter to buy and how to install a pure sine wave inverter in an RV, start with a few simple questions.
How often do you use (or plan to use) your RV or van off-grid?
If you are planning to boondock or stay in off-grid campgrounds often, and you want to use your laptop, coffee maker, instant pot, blender, or any other AC appliance with a standard plug, you’ll likely want a large inverter (or inverter charger). If you plan to camp in places with an electrical hook-up, then spend a night or two off-grid in between, you may only need a small inverter to run just a few things. We do fine with just 700W.
Does your rig already have a converter?
If you have a modern RV, this answer is most likely YES. In this case, you may just need an inverter. If you have (or plan to) install LiFePO4 batteries, the only caveat to this is ensuring that your converter is compatible with lithium batteries – check your specs! LFP batteries require a higher voltage charging profile than lead acid.
If you are building out a van or bus, or doing a complete electrical overhaul on a camper or RV, your answer is probably NO. In this case, you will need a converter plus battery inverter, or better yet, install an inverter charger and save yourself a step.
What is the total load of the AC appliances you want to run (at one time) while off-grid?
Determining your expected AC load is relatively simple and will help you appropriately size an inverter. Download and complete this worksheet to determine the wattages of your AC appliances, then see below for how to calculate your AC load, in addition to sizing an inverter for your AC energy demands.
How will you integrate your inverter into your RV?
There are various ways to integrate an inverter into your RV – ranging from very simple to much more complex. We describe these in detail later in this blog.
Renogy’s Line of Battery Inverters & Inverter Chargers
The highest quality inverters are pure sine wave inverters, as these most closely reproduce the specific type of AC power supplied by the electrical grid. Many modern electrical appliances, laptops for example, require specific parameters of AC power, and could be damaged if plugged into a different type of inverter.
Renogy’s pure sine wave inverters which come in a range of wattages. As noted in the chart belows, as the capacity increases, so does the price, size, weight, and power that the inverter consumes while doing its thing.
Renogy’s line of battery inverters can handle loads up to 700W, 1000W, 2000W, and 3000W, respectively.
How to Choose & Size an Inverter for Your RV
The type and size of inverter you need depends upon how you intend to use your RV, and the number of electrical appliances you want (or need) to run while not plugged into shore power. If you only plan to spend a few nights per week off-grid, and you don’t mind reducing the number of appliances you use during those times, you might be able to get away with a relatively small inverter like we have. However, if you want the ability to live mostly off-grid without sacrificing your typical AC power consumption, then you’ll need to install an inverter that can handle a much larger load. The amount you can run is limited only by your space constraints, the size of your battery bank, and of course, your budget.
To size an inverter, calculate your AC load, which is the total wattage of your AC appliances that you plan to run all at the same time. Let’s say you want to run your laptop, coffee maker, TV, and blender at the same time and the wattage on these appliances adds up to 1550W. Add an extra 25% of 1550W for a safe margin of error (1550 x 1.25 = 1937.50). You will need to purchase a 2000W inverter to be able to handle this load. If this number adds up to 850, you can easily get away with a 1000W inverter. If you are seeking to run a 10-15K BTU RV air conditioner (even for a short time), you’ll typically need at least a 3000W inverter and a large battery bank. In this case, you may also consider installing a higher voltage system such as 24V-48V.
3 Options for Installing an Inverter into an RV
Important Safety Reminder: AC is a power source that has the potential to be very dangerous. If you are feeling uneasy about your ability to disconnect the power source, and work safely while installing these components, please contact a licensed electrician or solar power installer.
One of the first things to consider is whether you’d like to simply create separate circuits or do a full Integration into the RV’s electrical system. Most Renogy inverters have two types of AC output terminals: hard wired terminals for AC wire and standard household GFCI outlets. Using the hard-wired AC output terminal, you could fully integrate the inverter’s output into your RV’s AC breaker box (distribution panel) or you could choose a simpler output solution by using the GFCI outlets and connecting the inverter to an extension cord or single household outlet. Below are 3 options:
1. Create Separate Circuits by Using a Dedicated GFCI Outlet (Using Battery Inverter)
This option can be done in one of two ways. The simplest option is to plug an extension cord into the inverter and use it to power any AC appliance when it is turned on. The second option is to wire a dedicated outlet or outlets directly to the inverter. These outlets will only work when the inverter is turned on. Example: Our 700W inverter distributes 120VAC power to 2 standard household outlets within the camper via a simple extension cord. This AC wiring circuit is separate from the original electrical circuit that came with our camper, which simply had one 120V household outlet that could be powered when we plugged in an external extension cord to a shore power source. Watch our full installation video.
2. Full Integration via Hard Wiring + Transfer Switch (Using Battery Inverter)
Connecting the inverter to the RV electrical distribution panel requires that you install a transfer switch. Without this switch, plugging your RV into shore power with your inverter connected will permanently damage the inverter because power will be running backwards into the unit. The transfer switch isolates the inverter from the shore power source. When you unplug shore power, it will switch back to the inverter power output source. The transfer switch will need to be installed in a split distribution panel, and make sure that the inverter and converter are on different parts of the board so that they remain separate.
Reminder: If your rig already has a converter, and you plan to use LFP batteries, make sure your converter is compatible with Lithium Iron Phosphate batteries. If not, this is a simple fix and installation, just check with your converter manufacturer for details.
Diagram compliments of RVwithTito.com
3. Full Integration via Hard Wiring (Using Inverter Charger)
This option comes with an integrated automatic transfer switch so you don’t need to deal with all the extra wiring and switch. Rather than isolating the shore power inverter sources separately, the inverter charger becomes part of the integrated circuit. When plugged into shore power, 120VAC passes through the inverter to the AC distribution panel; when off-grid the inverter draws power from the battery and delivers AC power to the distribution panel.
If you plan to install an inverter charger and your rig already has a converter, you’ll just need to disconnect the converter first – as it will become obsolete. Below is a RV inverter charger wiring diagram. This is a very simple process outlined in this video.
After ensuring that no power sources are going to the RV and the distribution panel, follow these steps:
Identify the converter (usually below the main distribution panel) and trace its wires back to the AC side of the panel.
Unscrew the AC terminal connections and remove the white, black, and ground wires.
Identify the positive and negative wires on the DC side of the panel.
Unscrew the terminal ends connecting those wires and remove them from the board.
Tuck the wires away and tape off the ends so that they are safely out of the way. Once you have removed all of the wiring between the converter and the distribution panel, you’ve made it obsolete. It is not necessary to remove the entire converter, unless you want to.
Now that you know how to choose and size an inverter or inverter charger, the next step is learning how to install it. Check out this blog for step-by-step instructions!
If you’re going to go off-grid with your RV, even for a short time, it simply makes sense to install an inverter. We simply couldn’t manage our off-grid life and small business in the same way without our Renogy 700W inverter. This device has been true workhorse for over 4 years now!
In 2012, Shari Galiardi & David Hutchison left behind careers and a comfortable home in North Carolina to travel with the vintage camper trailer they lovingly restored, outfitted with solar, and named "Hamlet." What began as a short break from careers and responsibility quickly turned into a love affair with roadlife. They have parlayed their higher education backgrounds, desire for life-long learning, and thirst for adventure travel into writing, photography, video production, and public speaking gigs from coast to coast.
Known to their friends as simply Shari & Hutch, you can learn more about their full-time, solar-powered adventures on their website at freedominacan.com. Or, follow them on Facebook, Instagram, and YouTube as “Freedom in a Can, LLC.”
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