HomeGenerators: More is not better

Overview

The standard, onboard RV generator is from 4.5KW to 6.5KW.  Onan is the primary RV manufacturer’s choice.

My RV came with a 5.5 kilowatt Onan generator.  This is OK if you are rich and do not care about the lifestyle of your neighbors.  Rich? It guzzles gasoline.  Neighbors?  It is noisy.  I have the latest Onan with the insulated side panel, etc.  Maybe you cannot make a 5.5kw generator quiet.  Maybe Onan has not been serious about trying.  The new insulated side panel is a reaction to the quieter competition.  Onan has been around forever and almost has a monopoly on RV generators.

Now, 5.5kw will run most of the RV as if it were a home.  5,500 watts is 50 amps at 110 volts.  In the average home, 5.5kw is about 3 fully loaded circuits.  It is certainly the TV, Microwave, AC, and a hair dryer -- all at once.  It also eats more than 1 gallon of gas in an hour.  You can watch the gas gauge go down.

You have to understand how these things work to totally understand the logistics.  Needless to say, the legacy generators can run at a multiple of 1200 RPM.  The RPM is fixed as it controls the cycles.  60 hertz/cycles is the US standard.

Since the standard generator does not output exactly 60hz, clocks may not run well and many UPS (for computers) will choke on generator power.

As in other places in my writing, if your rig is a diesel, then the generator is diesel and you must adjust some of the comments accordingly.

Courtesy

I used to tent camp in the National Forests.  These are great campgrounds.  Tent campers tend to live by the sun: they go to bed very soon after it gets dark.  They get up at sunrise.  In any case, occasionally after settling in for the night a big RV would haul into the site next door.  They would yell at each other for a half hour in the dark trying to position their rig.  Then on came the generator and the music.  Sometime around midnight, they would go to bed – with the generator running their air conditioner.  This is in the mountains where the nights are in the mid 60’s.

Now I have an RV and I have no one to yell at.  I hate to run my generator and I am still too noisy for the average tenter.  I think it is easier to teach lambs and lions to live together.  In most parks, the hours for generators is posted.  They lean toward the tenter’s hours.

I was in Dorn County Park in Bodega Bay this last week.  This is a nice park and it has some tent-only areas.  It has some backpacking tent sites.  It has other sites that are primarily used by RVs.  They are too small for tent usage since the driveway part of the site takes up most of the space.  Some tenters moved in next door to one of my friends.  Within minutes of the generator going on, the ranger said there was a complaint against the noise.  This was within the permitted hours.  The next day the tenter came over and asked if the blinds could be closed at night because the light bothered her.  We were courteous but had no intention of altering our life for her.  If she did not want an RV for a neighbor, she should have gotten a tent site.  If she wanted to live in mixed company, she should know that she is not the only life in the campground.

I have seen both sides and I think that it is best if each stays on his own side of the fence.  Then again there are those who dry camp in an RV park.  The people who live there like it quiet and peaceful.  They do not like to hear the roar of a lawnmower or something that sounds like one while they are enjoying the stars.  RV parks often limit generator hours to just a couple during the midday to run the AC units and to recharge the batteries.

Having said all of this, I also think the attention to noise pollution by Onan and the others is seriously belated.

Considerations

Engine Size is Power

The bigger, the more gas it uses.  Generally using the least gas is considered good.  Power is power.  That is, horsepower determines the number of Kilowatts, and that is determined by cubic inches of engine size.  This is contingent on efficiencies but everyone tries to be efficient.  The more cubic inches, the noisier.

In general, the larger the unit, the more gas it uses even when no power is being consumed.  Honda now has a dual-load unit which switches between 1.5KW and 3KW.  This solves both the idle and the full-load issues.  At 1.5KW you can stand next to it and hardly notice it is running.

You must decide how much power you are going to use when determining the size of generator that you need.

Hint: If you run off of a generator, switch your refrigerator to the gas position.  A gas refrigerator running on electricity is very inefficient.  Also watch your hot water.  I last six months between propane fills because I only heat my water when it is cold and I need a bath – and it is always on the gas position.

Sound Insulation

You see the little red thing that looks like a big gas can with a pull handle?  That is the 1KW Honda.  It has a molded plastic cover over the entire unit, including the muffler.  It is almost silent.

See that oversized tubular frame with the vented cylinder head in the middle?  That is the Coleman.  It puts out .9KW and sounds like a motorcycle climbing a hill.

Even Onan has gone to covering up its generators.  My Marquis Gold is enclosed in its space in the RV.  The original equipment had no other shielding.  It is located almost under the bed.  You could not sleep with it running.  I would not want to interview my neighbors in the morning.  The new one is quiet and smooth enough that I can sleep through it.  At 5.5KW my neighbors will still hear it but it is better.

Cooling

Some have fans to cool them.  In general the air-cooled ones do not have a fan.  They count on fins and airflow to expend the heat.  They may or may not be successful.

Some of them are now water or oil cooled.  This adds weight and complexity but make for serious sound reduction.  With liquid cooling, you have to worry about fans and thermostats.  The heat has to go somewhere so the water absorbs the sound and the heat.  The heat must be expended so there is a radiator like under the hood.  There is also a fan that blows air through the radiator.  This fan can make noise.  The fan noise should be less than the difference between the sound straight to the air and the sound through the water shell.

Fuel Injection

This in not in itself a noise reducing feature.  It comes under efficiency.  A fuel injection engine is seriously more efficient than a carbureted engine.  This means that it idles with less gas and it consumes less gas under load.  It is also more expensive.  Since it is more efficient, it loses less to pollution by unburned gas.

Efficiency

We have seen most of the efficiencies under the Considerations.  This includes fuel injection and water-cooling.  The water jacket makes the engine run at a more constant temperature.  This makes it more controllable and therefore more efficient.  Again, Honda has long been known for how efficient and how long its engines run.  I may sound like an ad for Honda.  May be I am but I am here to tell you, I have had two Honda motorcycles and will never own another.  I had to get a lawyer to get Honda to honor its warrantee both times.

Gas Supply

The onboard generator has its own hose into the RV gas tank.  Hopefully it is setup to not run you dry -- or you have no power and no gas to drive.  Mine will run the tank dry since the RV repair place did not understand this.

Properly installed, you may notice the ¼ tank rule when you try to start the generator and it will not start.  You may also notice this when the generator is running when it depletes the tank down to its hose limit.

If you have one of these problems, check the gas gauge before panic.

If you have a portable generator, then you carry a gas can or a siphon hose or both.

Care

A generator is a finicky thing.  All generators require regular care: (See my brand-descriptions of generators)

Use it or lose it

The Onan (maybe others?) generator has a peculiarity: "use it or lose it".  The manual says -- and it is true -- run it at least one hour per month or the thing will clog up on you, break seals, and otherwise do nasty things absolutely not covered on the warrantee!  If you are not going to run your Onan this often, before starting add a gas stabilizer (e.g. "Sta-bil"), and run the generator for a while.  It is better to run for two contiguous hours than run a few minutes at a time.

The problem: gasoline evaporates or breaks down into goo.  This goo will clog a carburetor jet and other things.  Once clogged, forcing regular gasoline or a gasoline additive will ultimately clean out the goo.  In the meantime your generator will run erratically, if at all.

Brand Choices

It seems that any company selling lawn mowers to motorcycles also has a line of generators.  Let's stick with 3 popular brands: Honda, Coleman, and Onan.  .  Yamaha and Generac are popular brands.  I see more and more of Generac.

Here you need to consider the electronics and fuel injection.  Fuel injection is good: it uses less gas. 

The electronics are changing fast.  Electronic regulators control RPM, voltage, and cycles much better than mechanical.  The current ultimate is an inverter rather than an AC generator.  Why?  True 60 cycle 120VAC is a continuous Sine wave that smoothly oscillates between +120V and –120V.  The mechanical generation of AC simply jumps between plus and minus with no attempt to match the mathematical Sine wave. This is acceptable for most things although they really don’t like it.  Some electronic devices know the difference and complain or are hurt.

Onan

Onan has started selling small units in the RV stores.  For me, Onans have always been hard to start, noisy, and generally a pain in the neck.  Unlike the Honda, they must run at the fixed RPM and they have a mechanical governor/regulator to do this.  You hear the Onan recovering and your UPS screaming as you change the load.  You will not believe the cost to replace the regulator.

Honda

Honda has been around for a while with the 1kw range and now we see it growing larger models.  Honda would sell many more units if they did not cost at least 50% more than their competition.

The Honda is well packaged in an indicative red case that also encloses the gas tank and the sound insulation.

The little 900w Honda is almost silent.  You can walk past one and not notice it running.  It gets about 8 hours on a gallon of gas.  But then it can run only one appliance and never an AC or heater.  It will take care of charging your 12v RV batteries and running the TV/stereo/computer.  Unless you live in the desert or the Arctic, 900w is almost enough.  It will not run the microwave.

If this is insufficient, you can get a bigger Honda.  Maybe up to 3kw.  You still get 4 hours on a gallon but it is hefty and is not so quiet.  Honda is always known for its easy-starting, quiet engines.  Remember the Honda lawn mowers?  You would never go back to a Briggs-Stratton.  Same here.  Honda has come out with a dual mode generator with either 1.5 or 3.0kw.  It runs either at 1200 or 2400 RPM -- manual switch.  At 1.5kw, it is almost silent.  At 3kw, it is still quieter than anything the competition puts out.  Looks like a great deal.

Honda has gone to full electronic conversion of 12V DC to 120V AC.  This means that Hondas are not locked into a fixed RPM like those with mechanical inverters.  This saves gas and noise and assures you that your electronic equipment is safe.

Honda-Powered

The Honda generators are very expensive -- about $800 for the 1kw model.  Be careful here.  The Honda name is so valued that other companies are adding Honda engines to off-brand generators and calling them "Honda-Powered".  These would be a bad choice for someone who wants a genuine Honda.  The Honda package is expensive but is exactly what it looks like: an extremely efficient, quiet, generator.

Coleman

Coleman has entered the market with the same power range as Honda.

Coleman is a great name in camping supplies and I guess they feel a need to get into this marketplace.  Seeing their machines, I have lost all respect for the Coleman Company.  For example, their “1100 Mite model” is a 2-cycle engine (you have to mix gas and oil) and generates only 900w (not the 1.1kw you would expect from the model number).  It has a metal wrap-around frame and looks like the toy that it is.  Coleman also has an 1800 model:  a klutzy-looking thing also with a tubular wraparound frame.  There is no sound insulation on either model.  Your camping neighbors will not love you: I suspect the Onan is quieter than the Coleman.  Last year the 1800 sold for $380 at Costco.  This year the 1100 model sells for $150 at Costco.  I hope they have many unhappy returns:  I like Costco -- they should know better.

My Choice

This is my synopsis on generators.  Honda if you can afford it.  Onan is catching up on the technology and a good second choice.

When I can afford one, I shall pick up a little Honda (1-2kw).  This should take care of my TV and computer needs.  Then I can turn on the Onan when I need additional power or for its monthly cleaning.

The Bottom Line

The bottom line is your bottom line: that is, your wallet and your lifestyle.

If you live in an RV park almost all of the time, and your RV has an onboard generator, use it when you need it and run it once a month for its exercise.

If you live in the woods or the beach or the desert, and you have an onboard generator, and a bottomless wallet, God be with you.  If your wallet has a bottom, you may want to lose the onboard generator and use the storage space for more important things.  You are a candidate for solar with a small generator for emergencies.  If you go solar, you need to look into serious battery configurations.

If you straddle the line, get a small Honda for when you are just enjoying life, use the onboard for AC when it is hot, and watch your fuel level.  I am ready for the Honda.  I am not ready for the Solar.

This month I bought a 1KW inverter and a 1KW Honda.  I need to increase my battery amps and then I can go anywhere.

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Written:  2003          Updated:  September 27, 2003          Back To Top