Are you new to the RV lifestyle? Then this column is for you! Every week we’ll walk you through the basics of recreational vehicles. We’ll help you get more assured of your rig, and make your travels even better. Today, let’s talk about a simple trick that can make for a happy generator.
Why exercise?
Your RV may have a built-in electrical generator. Others buy a generator to take with them to power up in the field. Whether your generator is built-in or portable, both need the same thing: regular exercise. An exercised generator is a happy generator. Why so?
Your generator’s internal components take a hit from moisture and a lack of heat. Engine seals do a better job of keeping lubricants where they need to be when the oil is heated up on a regular basis. Heat also drives moisture out of the unit’s electrical windings. And as a reminder to the operator (that’s you)—regularly exercising your generator may help remind you to keep fuel stabilizer in the tank, if your unit operates on gas or diesel.
Here’s your workout program

A happy generator exercise program begins with knowing its power output rating. That rating is in kilowatts or KWs. Got a portable Honda generator—like an EU3000is? That particular generator is rated at 3 kilowatts, or 3,000 watts, peak. However, the actual usable power output is 2,800 watts.
Armed with that knowledge, you’ll want to find a “load” or device to have it operate that’s at least half of the rated generator output. In this case, that would be a load that’s 1,400 watts or more. You’ll still need to stay inside the rated output, so nothing more than a 2,800-watt load. You can see how much “load” a given device will provide by reading the product info label on the device. If “watts” are not shown, look for “amps” and multiply that number by 120 to find out how many watts it uses.
Fire up your generator, let it warm up, then plug in the load. Let the generator power that load for a half-hour. The load will help the generator warm up, drive off moisture, and encourage internal seals to stay flexible. The workout will also help reduce the buildup of carbon. Exercise once a month, and all of these things can make for a happy generator, as you’ll likely see less of the generator repair shop.
Keep safety first! Be sure to operate the generator OUTSIDE, away from the RV or a house. Keeping the generator away from occupied places will reduce the risk of carbon monoxide poisoning.
Tune in next week for more “Know your RV” tips. And if there’s something about your RV that you’d like to know, drop us a line. Use the form below, and insert “Know your RV” on the subject line.
Update history: 6/18/22 1:17 PDT, corrected information on Honda generator output. 6/27/22 1649 PDT, add recommended exercise timing interval.
Sound advise. I make sure I use ethanol free fuel before storage along with a stabilizer. Av gas is even better if you can get it. Regular runs under load is also important. Even when I don’t need the power.
Your information is spot on. I knew all of this and knew better, BUT….
The 2800 W genset on my RV did not get exercised properly for a year and half because of my health and Covid reasons. Just last week I spent just over $1,200 to have the van jacked up and the generator dropped to have a new carb installed, as well as a full service. An ounce of prevention can be worth a WHOLE lot of money. Now I have to convince myself to exercise my body.
An ounce of prevention (exercising your body) is worth a whole lot more than money. If I can do it, you can do it, Kelly! Take care, and have a good night. 😀 –Diane
Thanks for the encouragement.
Certainly, Kelly. I learned the hard way to, as they say, use it or lose it. I sat at the computer all day, every day, and never moved around. It got to the point where my knees would barely function. I changed all of that a few years ago and feel much better, physically and mentally. Yeah, I’m still at the computer all day, every day, but walk a couple of miles each day, plus doing miscellaneous exercises for a few minutes throughout the day to keep my 75-year-old body moving for as long as possible. My doctor told me when I was 12(!) that my knees were already deteriorating much more than they should have been, so “no running and no downhill skiing.” I’m glad I got smart and started “moving” again, so I still have my original knees! Anyway, if I can do it, you can do it! Have a good night. 😀 -Diane
Yes exercise the generator on propane as well. Follow the service procedures in your manual.
The generator still has oil, and seals, and windings. They all benefit.
Probably the only thing you don’t need is gas stabilizer and non-ethanol gas😀 for obvious reasons.
OK. That is for gas engines. What about ones only on propane??? We have a duel fuel but will only use propane. Never gas.
Still need to exercise it monthly??
Does anyone have a good answer to that??
Yep. All of the above applies except for the fuel stabilizer. Even with propane, you do want to have some turnover and not be trying to use ten year old gas. And by the way, it does apply to diesel also, or whatever other fuel may be around the corner. All mechanical equipment benefits from being used, and all will deteriorate if not used regularly.
It is not only to exercise the motor itself, but to exercise the actual generator. Exercising regularly, in Onan’s case for 2 hrs, is to “heat up” the generator windings to get the moisture out. I had 13 monster Kohler generators, with John Deere diesels to power dormitories. They were set to automatically exercise for 1 hr each week.
Exercising a generator isn’t a “trick.” That’s the over used click-bait word writers employ. It’s a standard maintenance procedure to be followed for all generators.
Each owner should read and follow the specific recommendation of their generator manufacturer. For instance, while a 1/2 hour is often quoted, Onan recommends running the generator 2 hours every month at 50% load, and up to a full rated load if practical. Onan is a common brand found in many motorized RVs.
This practice isn’t just for RV type generators. If you have a home backup generator system, that should be exercised as well per the manufacturer’s instructions.
Even big commercial installations, like those installed at each Mississippi river dam location, get a monthly workout.
If you buy a used RV with a generator with very low to no hours, that may not be a good thing.
Our Cummins Onan 2800 manual is very specific on the exercise regimen. So are Cummins tech’s we’ve spoken to at rally’s. One 2 hour, uninterrupted, session per month with a minimum 50% load (22 amps in our case) for the full duration of that session. Running the generator for short sessions during the month is fine, and does no harm. Those short sessions do not reduce the need for the monthly 2 hour session though.
Daily, weekly, monthly, yearly? Did I somehow miss the frequency of exercising? If so, whoops!
Most say monthly.
The Onan manual that came with our rig says to run the generator at least 2 hours every month. That’s for an Onan generator, I don’t know what other brands recommend.
Honda 3000 generator is only rated for 2800 watts continuous. The 3000 watt rating is for surges only such as a refrigerator or air conditioner compressor motor starting up and lasting only seconds.
Couple of things: If possible, use only non-ethanol gas. Ethanol will rot small engine carburetors and plastic parts. Especially if they sit for long periods of time. (Ask me how I know) Second, years ago when I worked on an electric wireline truck in the oil field, we had gasoline generators built in. One of the operators rigged up a jar of water with a hose and bubbled air through it and suck the moisture air into the carburetor stream. It kept all the carbon off of the cylinders. They’re probably better generators nowadays but it worked real well back then.