The inverter – simplified! What you need to know

The inverter is a bit of RV technology that sometimes baffles people. Some folks don’t know if they have one, or where it’s located. Others aren’t clear about what they can use the inverter to power, and what they can’t. 

Similar to topics like RV solar power and tire pressure monitoring, understanding the inverter is easier than you may think.

Here’s a simple overview of what the average RVer needs to know, without diving into technical jargon or edge cases.

What is the inverter and what does it do?

An inverter is a device that allows you to plug things into electrical outlets even when the trailer itself isn't hooked up to campground power. Without an inverter, the electrical outlets in your Airstream will not work if you’re not plugged into campground power.

This means that if you are camping without hookups (boondocking), you won’t be able to charge or use things that require an outlet – like charging your laptop when you're enjoying a quiet boondocking spot – unless you are using an inverter.

The inverter makes this possible through a little electrical trick: it turns the power from the batteries, which is 12 volt Direct Current (DC), into 120-volt Alternating Current (AC),* which is the same power you use in your house. So with the inverter switched on, you can watch TV, play DVDs, plug in your laptop, and charge your devices at any time.

Where is the inverter in my Airstream?

Most Airstreams made in the last decade (except Basecamp and Bambi) have a factory-installed inverter. Look for a little control panel that has a push-button to turn it on and off. Although the control panel may look different depending on your model, in most trailers it looks similar to this: 

Older Airstreams might have an inverter too, but those are usually owner-installed, and their controls will look different.

How to use the inverter wisely

The fact that at the push of a button you can watch TV and plug in laptops and other devices while you’re boondocking probably sounds pretty good to you. And it is. But keep in mind the inverter does have a few limitations. 

The most important one is: the inverter isn't particularly efficient. 

When it’s turned on and you’ve got something plugged into it, the inverter itself consumes (wastes) 10-20% of the power coming from the batteries. That means there's a larger hit to the batteries than you might think, whenever you use it to charge a device or watch a DVD. 

Put another way, you’re always using 10-20% more battery power than you think to run things off the inverter.

So let’s cover a few essentials for using the inverter wisely. 

1. Use inverter power sparingly

    You can (and will!) run out of power if you're not thoughtful about how long you keep the inverter turned on.

    The inverter runs off the batteries in your Airstream. And the factory-installed batteries are designed to support the Airstream for a day or two of "typical" needs.

    So realistically, if you’ve got factory-installed (non-lithium) batteries, and you turn on the inverter and use your laptop computer all day, there won't be much power left for the next day—unless you also have solar panels or a generator.

    My advice: If you're a frequent off-grid camper and heavy user of the inverter, talk to a good service center about adding more battery capacity or switching to lithium batteries.

    2. Use only low-power appliances

    The standard inverter installed on most Airstream trailers up to model year 2023 has a rated capacity of 1,000 watts. That's plenty for low-power devices like the TV, DVD player, toothbrush charger, or a laptop, but not nearly enough for some other appliances – for example, a toaster. 

    Starting with the 2024 model year, Airstream upgraded the inverter to 2,000 watt capacity in most trailers, and a whopping 3,000 watts in the Trade Wind model. These higher capacity inverters allow you to plug in more power-hungry devices, but you still need to be mindful of what you plug in because they’ll chew up your batteries like a hungry bear.

    Rule of thumb #1: If it has a heating element, you probably shouldn’t try to run it from the inverter. 

    This includes a hair dryer, toaster, coffee pot, space heater, waffle iron, electric skillet, etc. These things often use up to 1,500 watts, which will overload the smaller inverters and stress the bigger ones. If you overload the inverter it will probably shut itself off—and it may burn out permanently.

    Rule of thumb #2: If it has a motor, think twice before using it. 

    Most things with electrical motors need too much power. You probably already know that the air conditioner and microwave will never work if you’re not plugged into shore power. They aren’t connected to the inverter at all, so they simply won't go on. 

    But you should think twice about running a vacuum cleaner or another appliance with a motor. At the very least devices like these will drain the batteries quickly – and worst case, they might overload the inverter.

    3. Check the label before you try to plug it in

    Not sure if the device you want to plug in is safe for the inverter? Every electrical device has some sort of labeling to tell you how much power it needs. For example, this is the label printed on my laptop charger: 

    I apologize because this involves a tiny bit of math, but all you need to know in order to read a device’s label is that amps x volts = watts. 

    (I promise that’s the most complicated math we’ll cover here.)

    So, looking at this label, we see "Input: 100-240V." That means this charger will operate on any voltage from 100 to 240. (Which means you can use it in Europe!) In North America, it will run quite happily on 120 volts.

    Now let’s take that number and multiply it by the next number. If you squint you'll see that it says "~0.75A" which means it draws a maximum of about 0.75 amps. 

    Remember the equation from above: amps x volts = watts. So by multiplying 120 x 0.75, we come up with 90 watts. And that’s good news because 90 watts is far below the 1,000 watt rating of my inverter. So I know it will be no problem to use this charger.

    (If you’re wondering why it’s labeled as a “30W USB Power Adapter” when the fine print says it needs 90 watts, it’s because there’s some power lost along the way. The adapter outputs 30 watts, but it can consume quite a bit more power than that.)

    My advice: Do this bit of math on any device you want to plug into the inverter.

    And just for geeky fun, take a look at some of the things you might plug in. You might be surprised (dare I say "shocked"?) by the range of power requirements that a coffee maker or iPhone charger requires.

    4. Turn the inverter OFF when you're not using it

    Even in "standby" mode with nothing plugged in, the inverter uses power. It's not much at any given moment, but just like a dripping faucet can eventually fill a sink, that power drip adds up to quite a lot over the course of a couple of days. 

    My advice: Only turn on the inverter when you really need it, and turn it off when you don’t. Like after you finish watching a movie.

    5. Be mindful of the heat

    Remember that 10-20% power waste we mentioned earlier? It’s released into the air as heat. Although the inverter has a pair of fans to keep it cool, on a really hot day, the inverter can get too hot—and that's bad for the longevity of the inverter.

    Most of the time this won't be a problem because frankly, only the hard core among us are willing to boondock in high temperatures. But if you pull into a boondocking spot after a sunny day of towing and the interior of the Airstream is over 104 degrees F (which can happen easily in the summer), the inverter will be over its safe maximum temperature. 

    My advice: If the Airstream interior is hot, wait for the internal temperature to drop below 104 degrees F before switching on the inverter. Monitor this on your wall-mounted thermostat.

    6. Use the inverter for more than device charging and DVDs

    Although most people go for these two common uses, the inverter is handy for other jobs too. Here's one of my favorite hacks: Plugging in a portable air compressor to top up the trailer tires during a trip. 

    I did the math described in tip #3 to calculate that my inexpensive portable compressor draws just 130 watts of power. So even though it has a motor, it's well within the capacity of my 1,000 watt inverter. Anytime I need to top up the tires, I just flip on the inverter and plug in my compressor. Beats the heck out of trying to find a power outlet or a gas station air compressor.

    An important note: The exterior outlet on your Airstream may not be connected to the inverter. So for a hack like this one you may need to run a good heavy-duty extension cord from one of the interior outlets. You should carry one in your rig.

    That's probably all most people need to understand about inverters. I hope this simple overview helps you understand that it’s a really handy device – as long as you understand its limitations and use it in moderation.

     * The voltages mentioned are not exact. Household current, for example, can run from 108 volts to 132 volts and still be considered normal. The WFCO brand inverter in a late model Airstream is actually designed to output 115 volts. Likewise, a "12-volt" battery is really going to put out about 12.6-13.0 volts when fully charged. This voltage drops as the battery is depleted. You didn't need to know this and it really won't change anything written here, but I mention it because otherwise, somebody will feel the need to "correct" me.

    BatteriesElectricalPowerRv solar


    Kathy Denny

    Kathy Denny

    Great information!!
    Thank you.

    Les Croland

    Les Croland

    I’m a little confused. I have a 2023 Airstream Flying Cloud (25 foot). My refrigerator runs on electricity (no propane). Your Newbies Guide (page 20) is not clear to me on whether the refrigerator will run on the batteries using the solar panels that came with my Flying Cloud. I have two 100 Watt Battle Born batteries. Please clarify for this techno dummy.

    Cheryl Toth

    Cheryl Toth

    Hi Les, Actually, your solar panels don’t “run” anything. All they do is charge the batteries. The batteries then run your electric refrigerator, and other appliances that run off the batteries. Hope that clarifies things for you.

    Nancy M

    Nancy M

    Great info as always Rich and Tothie!!! If I happened to leave the inverter on….. Would it really kill the batteries? Wouldnt the solar replenish them?? Also, is there still a danger of overheating if theres nothing on drawing from it? (Assuming 200 Amp hr lithium batts, 300W solar, sunny but cool weather.)

    Rich VanOrsdale

    Rich VanOrsdale

    Great info! So well stated my non-engineer wife understood it! Of course, we are “Glampers” and don’t get much of an opportunity to use our inverter. (The on-the-road use to power an air pump is one noteworthy exception!). Thanks!!

    Rich Luhr

    Rich Luhr

    Nancy, here are answers to your questions:

    1. Whenever the inverter is on, it is using battery power. So yes, eventually it will run down the batteries. A WFCO brand 1,000 watt inverter, for example, will draw about 1.8 amps continuously when it is on—plus whatever you’re powering.

    That background power draw alone will use about 22% of your lithium batteries’ power every day. That’s a lot!

    2. Solar can make up for that load, but you’re essentially spending the first 43 amp-hours of solar production just to make up for the inverter’s wasted power. That might be all the power your panels can produce on that day, if it’s partly cloudy.

    3. At about 104°F (40°C) the inverter will begin to protect itself automatically. It will start by “de-rating” itself, meaning that it will lower the wattage it can produce before overloading. For that reason, it’s not a great idea to put a load on an inverter that’s hot.

    If it’s not being used, you should just turn it off to save power. There’s no value in leaving the inverter on when it’s not needed.

    Nelson Haukap

    Nelson Haukap

    Hey Les – I think the short answer to your question is, yes, your (12v electric only) refrigerator will happily run off of your battery power. As for how long it will run, that’s subject to variables like what temp you keep it set at, how much food is in it, and the charge state of your batteries. But if you’re lucky enough to be in full sun, your solar panels will definitely work towards charging the lithium batteries , which will in turn extend the run time of the refrigerator (or any other items you run on the 12 circuits). I don’t have the info in front of me, but the watt/amp draw of the refrigerator is a “known number” in its instruction/owner’s manual, so with those numbers you can do the math that Rich described in the article to get an approximate idea of the refrigerator’s load on your batteries. My situation is the same as yours and I’ve been meaning to do this ciphering myself so I can have at least an idea of what the power draw of the refrigerator is.

    Nancy M

    Nancy M

    Wow, thank you so much for the comprehensive reply!



    I love you article as all ways , so my question is as follows!!
    I have a vintage airstream 1994 axcelka classic , once not using the airstream for a few weeks what do you recommend, disconnect the battery ? Keep plugged in to my home or shut the switch for the inverter?? And disconnect the battery ,I only have one .
    Thank You

    Jim P

    Jim P

    I’ve always wondered whether I should leave the inverter on for 5 minutes or so after running a high load (we run an 800 watt blender for a few minutes). My thought was to let the fans help cool the electronics before shutting it off. Is there a best practice for such a situation?

    Rich Luhr

    Rich Luhr

    George: You should read our article on storing the batteries. You’ll find it here:

    Short answer: In your case, with an older trailer that has a single-stage power converter, the best solution is to disconnect the negative cable from the battery.

    Rich Luhr

    Rich Luhr

    Jim: Best practice is to turn the inverter off. With no load on it, it will cool naturally and you won’t waste power.

    Mark Couron

    Mark Couron

    If we’re hooked up to shore power, does the inverter have to be on or not an example would be if you needed to use a CPAP machine in the evening whether or not the inverter needs to be on

    Rich Luhr

    Rich Luhr

    Mark C: Whenever you’re hooked up to shore power, the inverter is automatically bypassed, so it doesn’t do anything. So no, you don’t need the inverter for any reason if there’s shore power available.

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