Installation Report and Review of the Onan QG 2500i Ultra-Quiet RV Generator

And there we were, August 2021, off on another adventure to the “world’s first national park.” Yep, you guessed it, Yellowstone. With 12 campgrounds and over 2,000 sites, we’d scored on park reservations eight months prior to dry camp nine days in our Arctic Fox 990 at three different campgrounds (Pebble Creek, Madison and Canyon) before we headed down to the Grand Tetons. COVID restrictions or not, we were all in.

Sound Limitations

The last national park we stayed at was Death Valley in the spring of 2016. It’s the only national park that allows boondocking. But as we delved into the detailed campground planning in Yellowstone, we noticed something we’d not seen before or, if it was there, never paid any attention to it. The two campgrounds we had reservations for (Madison and Canyon) only allowed generators within specific use time windows, with a subtle tiny note of a “60 dB limit.”

Generator use is strictly prohibited in all dry camping areas of Yellowstone. I won’t list them, but recommend that you conduct the deep-dive on your own. Fishing Bridge RV Park is the only campground in Yellowstone with full hookups. Interestingly, as of this writing, Death Valley National Park does not have generator sound limitations (until they read this). They do have generator time to use windows, however.

Federal Mandates

Intrigued on the 60 dB limit, I did my due diligence to research this change. National parks, national forests, and BLM property are all codified under Title 36 of the Code of Federal Regulations or CFR. “The CFR is a codification of the general and permanent rules that were published in the federal regulations by the executive departments and agencies of the federal government. It is divided into 50 titles that represent broad areas subject to Federal regulation.” Chapter 1 of Title 36 pertains to The National Park Service (NPS), Department of the Interior.

Accessing the Internet, you’ll quickly find the National Archives does not post electronic versions of the CFR older than 1 March 2017. On this CFR webpage you’ll get a statement of: “The content you requested is not currently available in this version of the eCFR. The first date content is available is 1 March 2017 and can be viewed here.”

Continuing my research, I did find that beginning in 2000 the National Park System Director’s Order 47 specifically addressed, “National Park Service operational policies that will require, to the fullest extent practicable, the protection, maintenance, or restoration of the natural soundscape resource in a condition unimpaired by inappropriate or excessive noise sources.” A few years later the National Park Service published “Management Policies 2006” containing 180 mind-numbing pages of policies and direction to enhance the public experience in the national park system while preserving it. It’s filled with direction to monitor human activities to “minimize noise and other impacts” by limiting the mechanical and electrical generation of noise that adversely effects the park soundscapes and public experience.

So, as you can readily see the wheels were set in motion over 15 years ago to begin limiting noise in the US National Park System. How the 60 dB was implemented and when the federal register went out for “comments” on the proposed change I couldn’t find. Regardless, if you’re visiting a national park and intend to utilize a generator make sure you’re using a generator that can actually meet or exceed the noise limitation (if restricted by the specific national park you intend to visit). I challenge you to check the specifications of your generator. Unfortunately, most of the pre-2020, permanently mounted RV generators will probably not meet the 60 dB requirement.

Our 2013 Artic Fox 990

With our current set up consisting of Ford F350 and an Arctic Fox 990, eight nights of dry camping inside Yellowstone National Park, with only two campgrounds allowing generators with strict noise restrictions, was definitely going to have an impact on keeping our batteries charged. We don’t have solar, but we do have two large AGM batteries (176-amp capacity), but we do have an onboard Onan KVD 2500 generator and occasionally carry a Honda EU2000i generator. Thank goodness I’d previously installed a Victron Orion-Tr Smart 30 Amp DC to DC Charger Isolater and a Victron Energy BMV-712 Smart Battery Monitor, so we can easily charge and monitor the battery status either by the mounted display above the sink or the iPhone via Bluetooth.

As a technique we don’t let the AGMs ever get below 50 percent depth of discharge (DOD) or around 90 amps total “alarmed” by the battery monitor. I know AGMs can go as low as 80 percent DOD, but I just don’t go there by practice. I won’t go into a deep-dive on batteries, types, DOD, or charging here as there is a plethora of information out there to consume and apply to your own personal setup. Without even looking at the specification chart for the OEM Onan KVD 2500, I know it’d never even come close to the national park generator sound limitation of 60 db.  Heck, when our Onan is converting fossil fuel to noise, and under load, it’s as loud as a leaf blower, vibrates the camper until the picture frames fall off the walls and then wakes up every living thing within 50 yards. I’ve never been a fan—more like embarrassed—to even fire the dinosaur up. Man, that thing is loud!

Mitigating Risk for Trip Success

Truck camping is all about tradeoffs with the number of fuel sources being a major consideration. Our 2003 F350 Dually 6.0L Power Stroke runs on diesel—there’s one fuel. My Arctic Fox 990 camper is equipped with dual 30-pound liquid propane gas (LPG) tanks, which will hold approximately 7.14 gallons each—there’s another type of fuel. And, the portable Honda EU2000i generator (if taken) runs on gasoline—yet another type of fuel. Modifying the Honda carburetor to accept propane or natural gas isn’t an option, because I use it on other outings with my Polaris side-by-side. With the Honda needing gas, I’m stuck bringing along extra gas cans. Yes, that Honda can run a good 10 hours on one tank of fuel, but you always have to plan on using it more than planned. The 30 Amp DC to DC Charger, which gets juice from my 230-amp Leece Neville truck alternator, is simply outstanding, but it’s only useful if the truck is running (activated via a solenoid from an upfitter switch in the cab). What I like about that alternator is at idle it will produce 14.4 volts effortlessly.

The beautiful thing about Yellowstone is there are so many places to visit and just hanging out in a campground is a total waste of time. For us, we were not stationary at a campground during our stay at Yellowstone as there is just way too much to see and do. So, anytime we were on the road visiting areas in the Park, the DC to DC charger was “on” at least providing some level of “bulk” charging to the batteries. For redundancy during camping we always plan to have an alternative or backup to charge the batteries. Conservation is always a necessity regardless.

Generator Options

Needing another backup, the Honda EU2000i got a confirmed seat on the trip to Yellowstone. So, along with it came the associated logistical support which included gas cans. The downside, of course, is less space for something else, additional weight, spillage, fire, odors, and potential theft. We had a wonderful time in Yellowstone—it’s a must see. I might add there were at least four days of solid overcast and occasional rain while we visited, so solar wouldn’t have been a benefit for almost 50 percent of the stay. The addition of the DC to DC charger turned out to be the penultimate upgrade. We only used the Honda two times, but using it and just cursing the Onan KVD 2500 for being a paperweight got me thinking. One, it’s time to remove the Onan and/or put something in its place that’s usable, sustainable and adds redundancy. Two, I need to quit “kicking the can” and add solar to my already installed DC to DC Charger. However, like I said above, solar wouldn’t have been available during half our stay. Lots of folks get themselves in a real pickle relying on 100 percent solar. Three, carrying around two generators is foolish and “fuelish” (look that one up in Wiktionary.org).

Generator Research

So, when we got home the research began on options. I preferred something that could utilize the current onboard fuel. I would accept other options, but only with the existing truck and camper onboard fuels—diesel and propane. After an exhausting search, I actually came up with a surprise. A new, recently released, Cummins Onan QG 2500i LP HJLAA generator. What? Yep, Onan released an updated 2500 generator in 2020. A model with inverter technology—about time! Finally, Onan had upped their game in the RV arena with a more technologically advanced, efficient, and quieter generator. But the devil is in the details.

Onan QG 2500i Deep Dive

Now I needed to see one of these to believe what they were selling. Quiet—supposedly quieter than the 65 dBa at 50 feet national park requirement—less vibration, improved altitude performance, variable speed, better fuel efficiency—advertised at 89 percent better at full-load—easier maintainability, easier oil fill and oil measurement, easier air filter access and replacement, cleaner power to run the newer electronics, and a wiring harness that will grandfather old four wire start/Hobbs meter panels. In fact, its specifications say, “half load at 3.05 meters (10 feet) the set sound is: 64 dBa. That easily exceeds any national park requirement. Plus, it’ll easily start and run one 13,500 BTU high efficiency air conditioner (15.5 amps or less) plus a 600 watt base load. It also comes with a limited three year warranty. Hmmm, interesting.  I continued my Internet deep dive. I found Cummins had some videos of a 2500i static demo and other presentations with great graphics and a static Generator on their site. Then I found a great November 2020 video on YouTube by Cummins which visually showed all the things I’d been reading about this new generator.

A further search of YouTube came up with user “Delta Bravo,” also a truck camper enthusiast, who had unboxed and then made a video of the Onan QG 2500i LP HJLAA RV generator operating and confirming it was as quiet as what is advertised. He, however, did not include any installation tips, how to’s, tricks, ease, or issues he encountered.

Will the new Onan generator fit?

The new Onan QG 2500i is slightly larger, so I measured my truck camper compartment to confirm it would fit—tight, but it’ll fit. The 110 volt electrical box would have to be removed and reattached at the top forward side wall to ensure depth clearance. Next, I measured the opening in the bottom of the compartment confirming the only way possible to get this in would be through the door. Next, I measured the door opening. It confirmed there was no way it would fit just going in with the access door open. The last option was the measurement with the door frame removed. If the outside door frame opening was too small this would be a full stop. Extrapolating the frame and frame width (installed) it appeared it would fit through the door frame once removed. It was going to be a tight vertically, but it would fit. Satisfied, we pulled the trigger. Before we go further let me just say this is NOT a form fit replacement. It necessitated a totally different mounting structure and therefore I would not recommend this modification to a novice due to tools, materials and fabrication required.

Onan QG 2500i Purchase

In September 2021, I contacted Las Vegas Cummins/Onan and inquired about purchasing an Onan QG 2500i LP HJLAA generator. “Mr. Taylor, we don’t have any in stock and we show the earliest possible delivery to you in January 2022. “What? Can you repeat that?” “Yep, right now I show all these going to the OEMs for their new models, we have none available until January 2022. I can put your order in and I’ll note you’d prefer one earlier.” So, with the order in, all I could do was wait.

In November 2021, I got an unexpected call from Onan saying, “Mr. Taylor we just got an Onan 2500i here with your name on it.” “I’ll be right down,” I said. When I picked it up the warehouse, the loader asked, “how did you get your hands on one of those. This is the first one we’ve seen here, they are extremely hard to come by right now and this is the first one I’ve seen delivered to our warehouse.” I signed for it and with a forklift he loaded it onto the F350 dually and I headed home. By the way, it’s boxed in a wood pallet wrapped in cardboard and secured to the pallet. It’s a neat little compact generator and weighs in at approximately 110 pounds. Once home I unboxed it to get the serial number and registered it on the Onan site for the warranty. I then downloaded the operator and installation manual which I referred to extensively during my installation.

Let the fun begin!

It was pretty easy to remove the old Onan KVD 2500 genny. I unplugged the shore power and turned the battery shutoff under the sink to “off.” I shut off the propane at the tanks, removed the connectors and disconnected the lines inside the generator compartment at the “T” for the bumper grill port quick disconnect (QD) and the line to the generator. Next, I got underneath the generator and sprayed the exhaust studs/nuts with penetrant and let it sit overnight. I took off the exhaust system first while attached to the camper just in case I needed some leverage. Just remove the two nuts from the studs attaching the muffler to the generator. Save all the hardware. Remove the hangar and you’re done. The new Onan QG 2500i comes with an internal muffler so I didn’t need the big round muffler anymore. More on the new exhaust later.

Next, I unscrewed the two screws on the cover to the 110 volt electrical box in the generator compartment. I removed the wire nuts connecting the wires and removed the conduit nuts and fittings, so the wiring harness would come out with the generator. The old generator sits on four mounts attached at the side of the generator and the camper frame. They are basically mounted via “L” brackets. I removed the bolts and nuts where they mount on the camper frame. I left the “L” bracket attached to the old KVD generator as it is too tight to get an Allen head socket or wrench down along the side of the genny and the frame wall to remove the Allen bolt that attaches the “L” bracket to the generator—basically impossible. I grabbed a floor jack, made a small wooden platform and jacked it up. I was able to reach up and disconnect the DC generator wiring harness (four wires) connector that ultimately goes to the start panel next to the sink inside.

Next, I disconnected the 2 AWG positive and negative battery cables to the generator, zip tied them together and wrapped electrical tape around the red positive cable and capped it with a green dust cover because I quickly found out that line is always “HOT.” Next, at the battery box and disconnected the positive line to the genny—just for added measure. Once all the umbilicals were detached (110 volt electrical wires detached from the utility box, four wire harness, main battery cables and propane line) start working it down and through the opening. The old genny came out of the floor opening relatively easy—however, some persuasion was required.

Remove the Door Frame

In order to get the new Onan KVD 2500i installed, the generator access door frame has to be removed. I think I dreaded this job the most. I left the door attached, locked and latched, then took out about thirty screws which secure the access frame to the camper. Next, grab a plastic wedge or strong metal putty knife and start prying to unstick the Dicor underneath the door frame to separate it from the camper. Careful not to mangle the frame or the exterior wall of the camper. Slow is the name of the game. It’s a tight fit on the wall of the camper, but you can get it off. Once off, you can either disconnect the tail light electricals from the door and move it somewhere it won’t get banged up or turn the entire frame and attached door upside down and attach it to the ladder out of the way.

Generator Compartment Preparation

Now that the compartment was clear, it was time to get it ready for the new generator. Just to double check measurements, I put the old generator mount brackets on to see if there was any way to modify them to work with the new generator. There wasn’t. Detach the existing electrical panel inside the generator compartment. Move it up to the top, drill a few holes and reattach it with screws. Make sure the area where you mount it has room for the electrical shielding conduit fittings etc. Measure, cut and attach a small section of 1/2-inch vinyl flexible electrical wiring conduit to the existing camper side 110 volt conduit and route it to the newly remounted electrical box. Once the existing 110 volt camper wires were routed into the conduit to the electrical box, I had only about 2 inches of wiring inside the panel—not optimum but workable.

Next, secure the conduit at the electrical box with conduit fitting connectors and then secure the conduit line with Adel clamps in three places. Now that the electrical box is finished remove all the compartment Adel clamps for the electrical conduit, so it’s not attached to the compartment. Next, remove the Adel clamps to the propane lines in preparation for the next step. Pay attention to where these mounting holes are so you can use the same holes after you cover them up with sound deadening.

Compartment Sound Deadening

With all the lines unattached, I wiped down and cleaned the aluminum compartment panels with degreaser and alcohol. Next, I cut and fitted KilMat 80 Mil which is a sound deadening material, and then with its self-adhesive backing covered the entire compartment. I took out a heat gun and warmed the KilMat then pressed it in with a roller to ensure the adhesive stuck well to the inside panels. I figured if I was in there, I’d make it even quieter. I even added new vibration mounts to further reduce the constant resonance. More on that later.

Final Preparations

Now that the compartment was almost totally soundproof, it was time to start reattaching the things you won’t be able to access once the new generator is installed, and that brings up an important point. For any future maintenance (besides oil changes, air filter changes etc.) like changing out a propane line, the generator will have to be unmounted for access. Resecure the propane line for the grill QD. Mine runs from the “T” to the corner then down and out the bottom. Pull the four-wire Onan connector up and temp zip-tie it at the top near the electrical box. Do the same for both the positive and negative battery cables. That way everything is easy to get to when you slide the new generator in. Reattach and secure the tail light harness to the compartment on the sides. Mark and drill holes at the top of the compartment just aft of where the tail lights on the generator door enter the compartment so you can attach an Adel clamp after the install.

On the Bench

While the new generator was still on the bench, I measured more vinyl 1/2-inch flexible 110 volt electrical wiring conduit to go from the newly remounted electrical box (top drivers side panel) to the new inlet on the back (forward in the camper) right side rear corner of the new generator.

Since Cummins leaves about 6 feet of wires for the install, I measured and cut off the excess wire from the generator, attached the flexible conduit, secured it to the generator, routed the wires through the new flexible conduit and taped it to the top of the generator.  The four-wire harness was also routed next to the flexible line and attached on the top of the generator (temporarily). I also kept everything looking neat and tidy with zip-ties as it came out of the generator. For the propane line I’d disconnected from the camper, I put a little gas line putty on the threads at the generator propane inlet (on the back right side), attached it, then I taped it to the top of the generator (temporarily). I could have gone with a shorter propane line with the new generator, but during pre-fitting I could easily half-loop the excess without impacting or kinking the line and disrupting gas flow.

Building a New Generator Mount

Again, this new generator has a slightly larger footprint than the old Onan KVD 2500. More importantly, all Cummins Onan mounting measurements and schematics are in metric. Buy yourself a metric tape measure and it’ll go more quickly than trying to convert all measurements to fractions. As for fit, the desired Onan clearance will be shorter by 6.35 mm to 12.7 mm (1/4-inch to 1/2-inch) on the sides. Therefore the “L” brackets (like which are on the old generator) will not work as there is no space. Further, none of the existing mounting holes on either the new generator or the frame will match. I made a template of the base of the generator to ensure it was centered inside the compartment.

Next, I drilled out new mounting holes in the camper structure to bolt the new frame to the camper. But, instead of mounting the new fabricated aluminum bracket directly to the frame I added four vibration mounts for it to sit upon and I also added a small piece of rubber under at the vibration isloators. These are M10 Male Female Rubber Vibration Isolators, 50mm x 40mm (you can find them on Amazon or a large hardware store). I secured the mount to the frame and utilized nylon nuts. This new mount allowed the generator to sit much higher in the compartment (bracket plus the vibration mount) than the previously mounted KVD to improve airflow both in and out (see pic below looking up).

Next, I determined it was going to be much easier to fabricate an aluminum 1×2-inch mounting bracket for the generator to be secured to. That mounting bracket would be attached to the camper frame on both the left and right side where I drilled holes to secure it.  Next, I utilized an 1/8-inch thick, 2-inch-wide aluminum strip to attach to the frame, so the mounting bolts for the generator if not attached to the horizontal mounts could mount to these. Then, on recommendation from my mechanical engineer son, I reinforced those strips with “Z” brackets riveted into the 1×2 braces. It made for an extremely stout mounting floor. Next, I drilled out the four generator attachment mounting holes in the aluminum (measure three times before drilling) structure for the generator to mount on.  Again, measure and remeasure then drill.

Onan QG 2500i Installation

Next it was time to put in the new generator and pray all the holes lined up. It’s 110 pounds so get some help. I put it on a small workbench right next to the camper so it would be a short move to the door opening. Lift and then rest it on the bottom of the door opening frame. Make sure you have attached and routed the propane grill (QD) supply line (at the “T”) so it’s out of the way. Attach the generator propane line (the line you attached while the genny was on the bench) to the “T” on the top of the compartment. Just get it started as you want to readjust the hose after its secured. I also attached the red positive battery cable to the generator rear lower positive stud (I should have put slid a silicone cover on the positive wire to secure over the stud, but just missed it).

Slowly maneuver the generator into the compartment and then secure it from the bottom with bolts through the holes pre-drilled in the new mount. Once attached, attach the electrical conduit line to the junction box and secure it with conduit connectors. Secure the wires with wire nuts—white to white, black to black and ground to ground.  Secure the electrical box cover. Next, adjust the generator propane line coming to the camper “T” above the generator to ensure no kinks or excessive bends restricting gas flow. Grab a wrench and tighten down the B-nut on the “T.” Secure the tail light wires with Adel clamps so they are out of the way if not previously accomplished.

Note: I should mention here that you can add a new Onan Energy Command 30/30G Start Panel with this new generator (it delivers with a compatible electrical connector on the generator) but, you’d have to wire a new harness to the area all the way above the sink. It has phenomenal capability—will even automatically start the generator when it detects the batteries are depleted to a capacity you input. Again, it is fully compatible with the new Onan 2500i, but you can do nothing and utilize your current starter panel if you want. I ordered a new (sink area) identical Onan Start/Stop Switch Panel, so I could save myself doing math every time I looked at the Hobbs meter. The old Hobbs meter could then remain with the old Onan KVD 2500 I removed and intend to sell with the current accurate total time.

One other area of concern for me was the vent on the generator compartment door. Northwood Manufacturing has modified these generator access doors numerous times for venting depending on the generator installed. My large opening on the generator door is on the left. The intake holes on the generator cover are on the right for this new model. The bottom line here is that I left the large opening on the left side of the generator compartment door, but added two 4-inch diameter round air holes just below the taillight for unimpeded airflow into the intake on the new generator. Just break out your 4-inch hole saw and drill two holes. I did get two round screened plugs to fit the hole as you can see in the photo at the end of the article.

Finishing up

Once I finished with the holes in the door there were only five things left; find a new negative battery ground, secure the exhaust pipe, reattach the auxiliary propane line to the camper for the grill, ops check everything and then reattach the door frame. I found these items took longer than getting the generator mount fabricated and the generator installed. I utilized the generator bottom tray to attach the negative battery ground since the existing camper cable was not long enough to attach it to the designated ground stud on the generator. I had to re-swage a new copper terminal then attached it with a bolt and star washer for a firm contact on the metal mounting bracket/tray.

For the exhaust pipe I went a little overboard. I added the Cummins Exhaust Resonator, which is basically a “glass pack” muffler (funny how I as a kid I thought these were the “bomb”) and tubing to exhaust it out the same area/place the old one occupied. I found some 90-degree bends and extensions from Onan and Amazon that fit the unique muffler pipe size. That took a little work, but came out the way I wanted it with two 90-degree bends. The muffler removes the continuous “putt putt” sound emanating from the generator.

For the propane grill line QD, I utilized Adel clamps and metal screws on the bumper frame to attach the line whereas Northwood used rivets to attach the clamps. I routed the line under the generator and far away from the exhaust and attached the propane line to the bottom of the frame with a large unencumbered Adel clamp.

Before I reinstalled the door, I conducted an ops check to make sure everything worked correctly, wires and propane lines were secured, and no leaks. First, I attached the propane lines at the bottles and turned them on.  Then I bled the gas line of air. I turned on a stove burner to confirm I had gas. For added measure, I grabbed some soapy water in a bottle mixed with water and sprayed the reattached propane lines at the “T” and the new connection at the back of the generator confirming no leaks. I left shore power unattached. Next, I returned to the battery compartment to attach the previously disconnected positive cable that runs to the generator, and then I turned the battery disconnect to “on.” With my voltmeter I checked for 12 volts at the new generator positive stud—good to go.

In continuing the preparation for an initial ops check, I carefully reviewed and inspected the wiring harness for kinks, proper connection, clearance from other metal and heat producing components, and reconfirmed the grill propane line had plenty of clearance away from the exhaust and other heat areas. Secure and attach everything suspect with Adel clamps and tie wraps. Don’t be afraid to utilize plastic wire loom wrap as well. Lastly, and just to cover all my bases, I referred to the Onan HGLAA Installation and Operators Manual and Onan Quick Start Guide once again. The Operators Manual requires you “prime the engine for 30 seconds if it has not run in over 8 hours, was run out of fuel, or the fuel filter [I’m guessing gasoline] was changed.” I would conservatively add anytime you “open” the propane line this should also apply. So, per Onan, I pushed the “stop/prime” lever for 30 seconds on my “new start panel” which showed “0” Hobbs’s meter hours.

My technique after running the starter that long is to let the starter rest a few minutes (cool down) and then start it normally. It fired right up and settled into idle right away. Rechecking for leaks, smoke, unusual noises all proved fruitless. It all checked out great, no codes, sounded quiet, and I failed to notice any excessive vibration. Impressive. Another ops check was accomplished after I installed the door.

For the door frame, clean off the old sealant. Grab a heat gun and then working in sections to heat up the Dicor and then scrape it off. Clean the area as well as you can. Once you have removed the old door frame and Dicor residue, reapply fresh Dicor non-self-leveling sealant around the frame and the structure. I like it to squeeze out the edges when you tighten the screws. Attach the frame with screws in the original holes and screw it down the frame to the structure. Don’t over torque the screws. Wipe-off the excess Dicor.

The Final Verdict

The new Onan QG 2500i is a game-changer. The difference between the old Onan KVD 2500 Generator and new Onan QG 2500i is stark with a significant reduction in noise and vibration. The difference is unreal. Inside, the noise is barely noticeable. Outside, only 10 feet from the generator, you can actually carry on a normal conversation. The only negatives I can think of right now is its price point ($3,265 is what I paid) and, should you order one, dealing with supply chain issues for the near term. Additionally, any installation in an older model RV or camper is probably “plug and play,” but only to a certain extent. The more important questions to ask is will it fit and how much modifying will I have to do? So, do your due diligence beforehand to ensure it meets your compartment size and your mechanical ability before you pull the trigger. For the RVs in production today, I’m fairly certain the Onan QG 2500i will be offered as a standard generator option. It’s that good.