When your old RV Onan quits—maybe right in the middle of your trip—this direct replacement brings back quiet, reliable power for your RV AC, fridge, and more, so you can keep exploring with all the comforts of home, no hookups required.
If your old generator finally gave out, this Onan QG 2800i fits in the same spot as your original. You'll still need to hook up the fuel line, electrical, and exhaust, but the major work is already done for you. Enjoy the comforts you count on—morning coffee, fully charged devices, and lights on at any hour. Plus, it has enough power to run one 13,500 BTU high-efficiency air conditioner, so you can beat the summer heat and stay comfortable wherever you park.
After a long drive or when the weather turns wet and rainy, nobody wants to wrestle with a bulky generator. With one-touch start, automatic choke, and remote switching capability, powering up is always simple, rain or shine. All you have to do is press the power button and relax. And the built-in shutoffs handle low oil, overloads, and engine quirks automatically, so you can settle in for the night with your fridge cold, your CPAP on, and no worries about unexpected shutdowns.
The built-in inverter delivers clean, stable electricity—perfect for laptops, tablets, and other sensitive electronics. No more worries about power surges or fried circuits. Your devices stay safe, your lights don't flicker, and you get reliable AC power for today's gear.
This generator uses sound-dampening technology and a special muffler to help keep things peaceful. You won't have to raise your voice for campfire stories, cut conversations short, or lose sleep to engine noise. It also meets National Park Service noise guidelines, so you can experience brilliant fall foliage in the Great Smoky Mountains or visit the steaming geysers at Yellowstone without worry.
From routine oil changes to swapping out the air filter, service is straightforward. No need to be a mechanic—just basic tools and a few minutes are all it takes to keep things running strong for years to come. And with built-in self-diagnostic capability, troubleshooting issues is faster and easier so you can spend less time on maintenance.
California residents: click here
Videos are provided as a guide only. Refer to manufacturer installation instructions and specs for complete information.
Hi, everyone. Steve here with etrailer.com. Today we're looking at our Cummins Onan UG 2,800i onboard RV generator with inverter with 2,800 watts of power. Run it on gasoline, and it's even carb compliant. Now, folks, this should be a simple, easy installation for you, as far as not having to worry about everything already built in place on the RV camper, whatnot. This should be a direct replacement, just make sure the dimensions match up to what you're swapping out with.
And, of course, the wiring harnesses that are here in the back, I'll show you in a second. But, other than that, it should be a straightforward installation. It should be pretty easy. You're just replacing one right in place of the other one. Now, like I mentioned before, it has a built-in inverter and that's gonna deliver clean, sustainable electric, that's stable, and it's gonna be perfect for laptops, tablets, and other sensitive electronics.
So you don't have to worry about power surges, or frying circuits. Your devices will stay safe, and your lights aren't gonna flicker. Now, zoom into the front here, as far as accessing the unit, as we said, it is carb certified, so you have that certification right here on the front, and you have all the information here, as well. You simply rotate this little handle in the direction that it says for open. pull down and out, and that's gonna let you access the inside.
You've got some sound dampening over here on this side. More importantly, now that you're inside, you can reach your oil fill, your air filters right behind here, and then, of course, your master switch here, go on and off, and that circuit breaker. Now, there are four bolts that hold this case in place. I went ahead and removed them, that way we can go ahead and take this case off, and get a better look at the inside together. So you can also see you've got that sound dampening on the side over here that matters, as well, and it acts as a heat shield for that muffler, too.
I'm gonna set that down to the side. Now, you can see a lot better. Again, you have access here to your air filter, so not just for maintenance and stuff, but maintenance is pretty easy, as well. So you're just gonna be doing a couple things, such as the air filter, maybe changing out the oil, and, you know, maybe cleaning out the fuel lines, or stuff like that. It's pretty simple. You don't have to be a mechanic. You just need some basic tools, a couple minutes of your time, and you could probably do that yourself. Again, you've got your master switch here. You've got a little circuit breaker switch right back in here. The muffler, it's a sound dampening muffler, meaning it's gonna be extra quiet. It has soundproofing and everything around it, so you shouldn't be hearing that as much as you did your old one. And, this is also a USDA spark arrester muffler, meaning it's safe for National Forests and campgrounds. So you don't have to worry about any kind of modifications, or add-ons. It's already set up outta the box ready to go. So right here you would pop this out, and on the inside, down in here, you have the the muffler. You have a ring gasket and a ring clamp. That's gonna go around here, and it's gonna come out of this hole, and that's gonna be for your exhaust. Maybe you have a longer exhaust, or a custom exhaust mount. That should mount up to that, just like your old one did. Coming around the backside, you got your positive and negative for your main battery hookup. You got your two main wiring harnesses. One here has a cap on it right now for shipping. But, these basically should match up right to the harness that's already wired up in the RV or camper or trailer that you're using. And then, of course, you have your main power wires that come up and out, and you would just finish connecting your conduit or whatever to there. You got your main fuel line, and your purge lines here. Those have red caps over 'em, to keep the threads protected during that shipping, as well. Now, this did come bolted down to a small pallet, so that's how it's gonna come. So you can rest assured it's gonna be fine in shipping. So now I wanna give you a quick top down view real quick, just so you can kind of see everything, as well. So again, everything is gonna be super quiet, with that sound dampening built into the case. It does meet all National Park Service requirements of that max 60 decibels at 50 feet. This also is equipped with built-in shutoffs for low oil overloads, and engine issues, or anything like that. So you can relax knowing that it's going to shut itself down, preserve itself, if any little issue arises. Well, folks, I think that is gonna wrap it up for our look together. If you don't wanna tackle the install yourself, reach out to us, or go to our website etrailer.com. We can help you locate a dealer near you with our dealer locator tool. And, if you have any comments about this, or questions, comment below. We'd be happy to hear from you. I'm Steven, thanks for watching.
Sam C- Product Expert (Solar & Electrical Systems)
If you're running lithium batteries in your RV, whether you're full-time, off-grid, or just solar-prepped—an Onan inverter generator like the CM25ZR, CM42ZR, or CM52ZR is an excellent choice for reliable backup power.
These models produce pure sine wave AC output, which is essential for charging lithium batteries safely, especially if you’re using a smart battery management system (BMS). Unlike traditional generators that can deliver "rough" or fluctuating power, inverter generators deliver the clean, stable voltage that lithium chargers and inverters require. This reduces the risk of fault codes, overheating, or improper charging.
Another benefit is how well these generators integrate with modern inverter/charger systems. A lot of lithium setups use gear that expects high-quality power if you feed it unstable current, the system might reject it or shut down charging altogether. The CM52ZR and other inverter models solve that problem by producing grid-like power that your system can accept with no issue.
Because the engine speed ramps up or down based on demand, you also get better fuel efficiency which is perfect when you’re just topping off your batteries after a few cloudy days or running overnight loads like a fridge and CPAP. Many lithium users also install auto-generator start (AGS), and these models pair well with that kind of automation.
If your rig is lithium-equipped and you want a generator that won’t fight your charging setup or worse, damage it, these Onan inverter models are designed with that compatibility in mind.
Heather A- Product Enthusiast at etrailer.com
If you have a Jayco Jay Feather or another lightweight travel trailer that's generator-prepped for gasoline, the Onan CM52ZR is a great fit.
With 2,800 watts of inverter power, it’s well-matched for trailers running a single 13,500 BTU A/C unit plus your usual essentials—fridge, lights, chargers, and small appliances. It gives you enough power to stay comfortable off-grid, without going bigger (and heavier) than you really need.
Since it's an inverter generator, the power is clean and safe for electronics like laptops and phone chargers, and it runs quieter than traditional models, which is great for campgrounds and early mornings.
If your trailer came from the factory with a generator bay ready to go, installation is simple, and you won’t need to carry separate gas cans or modify your system to make it work. The CM52ZR is a compact, efficient solution for folks who want reliable power without the bulk.
Kate F- Product Enthusiast at etrailer.com
I’ve helped quite a few customers lately who work remotely and need to charge laptops, monitors, and camera gear while they’re traveling. Whether they’re full-timing or just working from the road, one thing they all have in common is needing clean, stable power and that’s where an inverter generator makes all the difference.
The Onan inverter models, like the ones under part numbers CM25ZR, CM42ZR, or CM52ZR, are built to produce pure sine wave power, which is just a fancy way of saying they give you the same safe, consistent electricity you’d get at home. That means your laptop charger isn’t going to buzz or overheat, and you’re not putting wear and tear on your devices every time you plug in.
I always tell people, if you’re relying on your tech for work, Zoom calls, editing, charging your batteries, this is one area where you don’t want to compromise. Plus, inverter generators are quieter and more fuel-efficient, so you’re not stuck listening to a loud rumble all day while you’re trying to focus or take a call.
If your RV is your mobile office (even part-time), having an inverter generator isn’t just a luxury, it’s a smart move that protects your gear and makes work on the road way less stressful.
Chris R. – Product Enthusiast at etrailer.com
If you're trying to keep your smaller RV or camper powered up without overdoing it, the Onan CM52ZR hits that sweet spot between “barely enough” and “overkill.”
This one puts out 2,800 watts of clean inverter power, which is more than enough for your 13,500 BTU A/C, fridge, lights, and whatever else you’ve got running, just don’t try to microwave dinner, charge the e-bikes, and run the blender all at once. It’s perfect for the realistic power user who wants the essentials and a little more without stepping up to a bulkier 4,000-watt unit.
Jesse M-Product Enthusiast at etrailer.com (install and training team)
Install-wise, if your trailer has the generator bay already prepped, this is a pretty straightforward fit. It’s not heavy, so it won’t weigh down your tongue weight or eat into your cargo too much. And since it runs on gas, it’s one less thing to adapt if your trailer is already set up for it.
If you're doing a weekend trip or some off-grid time and don’t want to mess with a massive unit, this one hits a sweet spot. One thing I like about this unit, especially for folks out there in California is that it’s CARB compliant. I'm From Cali so I know those rules can be a pain sometimes, but if you’re trying to camp legally in state parks or just avoid the hassle down the line, this one checks that box so you don’t have to stress it.
Info for this part was:
At etrailer.com we provide the best information available about the products we sell. We take the quality of our information seriously so that you can get the right part the first time. Let us know if anything is missing or if you have any questions.
Thank you! Your comment has been submitted successfully. You should be able to view your question/comment here within a few days.
Error submitting comment. Please try again momentarily.