Onan 5500 and Honda 2000...can I run then at the same time?

B Traveler wrote:


If your next rig is a "B" similar to mine, you won't need another generator, just an inverter, to charge cell phones or to watch TV, and you don't need either to run the furnace. Those things will not run down the house batteries for several days, and driving will recharge them. I do have an small inverter.

The biggest battery drain I tend to have is the furnace, namely the furnace fans. In my experience, the furnace uses about 7-10 amp-hours, (and this seems to be independent of BTU). So, if I have two house batteries (either two 6V jars in series, or two 12VDC in parallel), I'm looking at two nights max before I cross under the 50% point which isn't good for the bank (either the battery bank, or the wallet when I have to replace them.)

To offset this, most Bs use a 45 amp converter. So, I'll be pulling at most 550-600 watts from a generator to charge up the bank. With this in mind, pulling out a 1000 watt red/blue that can run a good long while on less than a gallon of gas is probably the most economical way of recharging the batteries when I boondock. Since a generator is the most economical at a half load, running a 1000 watt model for four hours will get the house batteries up enough to withstand another day of worst case furnace use.

I could be wrong on these numbers though.

M GO BLUE wrote:
I run our Onan when we want electricity...period...and don't have to fool with anything else

Does not make any sense what most of you are doing...two generators?

You spend a lot of money on your RV and now you are trying to be cheap by running a Honda? To each his own I guess...

Not just about being cheap, at low load levels, the Honda is quieter, and mine runs about 9 to 12 hours on a gallon just keeping the fridge running and the TV/Satellite on. For 3 day weekends, we run the Honda 24 hours a day and never use all of the 6 gallon external tank. Burning less gas, and being quieter (when possible) DOES make sense, side benefit of the APU doesn't hurt either.

using previous math - $1.55 x 60 hours (my typical weekend) = $93, the Honda is free after 10 weekends. (Paid for itself in less than a year). (they're easily found for $700 to $800 in the used or barely used market). Even though my rig burns a lot of fuel, my generator doesn't have to burn an extra 23 1/4 gallons of gas a weekend.

If I were always in a campground, or where I wanted to run AC units all day long the Honda wouldn't get much use. Everyone's sitch is different.

mlts22 wrote:
I'm getting a small (1000 or 2000 watt) inverter generator with my next rig (assuming I get a MH with a built in Onan.) This way, I will have two options:

#1: The Onan running off the gas or LP tank to keep the A/C on or run the microwave.

#2: A small portable generator running to keep the batteries fairly charged (offsetting the loss from the furnace), run a 750 watt electric heater, or charge up cellphones/laptops. The small portable comes in handy if the house batteries get run down, preventing the Onan from starting. Since the small generator is thrifty when it comes to gasoline, it is the best to run when just needing to keep things topped off.

If your next rig is a "B" similar to mine, you won't need another generator, just an inverter, to charge cell phones or to watch TV, and you don't need either to run the furnace. Those things will not run down the house batteries for several days, and driving will recharge them. I do have an small inverter.

My built in transfer switch defaults to the onan. If it is running, it is primary. In your example, you could start the onan, leave the honda running, run the microwave, shut down the onan, and move on. As far as the ac, start the onan, start the ac, shutdown the honda.
I have a 3kw inverter/charger on my trailer, and I still have the old 100 amp converter. I am thinking about wiring the old converter back into the 12 volt side, and put in a seporate power inlet - just for it. Then I could run whatever off the inverter, with a honda 2k running the converter - trying to charge the batteries / run the inverter. The batteries would cover any shortfall (for a limited time), and the honda / converter would be extending the time the batteries can run the inverter. When I need it, the onan is still there and can run whatever loads, and recharge the batteries fast.

I'm getting a small (1000 or 2000 watt) inverter generator with my next rig (assuming I get a MH with a built in Onan.) This way, I will have two options:

#1: The Onan running off the gas or LP tank to keep the A/C on or run the microwave.

#2: A small portable generator running to keep the batteries fairly charged (offsetting the loss from the furnace), run a 750 watt electric heater, or charge up cellphones/laptops. The small portable comes in handy if the house batteries get run down, preventing the Onan from starting. Since the small generator is thrifty when it comes to gasoline, it is the best to run when just needing to keep things topped off.

Mine defaults to the house generator anytime its running. So I can have the Honda running for normal house loads, fire up the house generator, do the MW, oven, etc. and kill it when done without going outside. The inverter picks up the qlitch switch of the ATS so the power is uninterrupted.

X2! Exactly what I do!!

.111 gal/hr vs .5 gal/hr = .39 gal/hr saved or $1.55 per hour. ($4/gal)

Cost of Honda $900? Gives gasoline payback in 578 hours run time.
Could be other returns such as reduced service on the Onan vs Honda.
Having a portable Honda could serve other needs.
Honda might be quieter that gives subjective value.

Honda 1000 might be an even better value.

Beauty of camping is we all get to do it our own way, priceless.

TRIPLE8 wrote:

M GO BLUE wrote:
I run our Onan when we want electricity...period...and don't have to fool with anything else

Does not make any sense what most of you are doing...two generators?

You spend a lot of money on your RV and now you are trying to be cheap by running a Honda? To each his own I guess...

Hi, My onan uses about a half gallon of fuel an hour to charge batteries, my honda will run about 9 hours on 1 gallon with the same load.

Ok using your theory on saving gas with the Honda compare that with the original cost of the Honda and let me know how long it will take until you come out ahead...I would probably start at 10 years and work your way up :R

But like I said to each his own...

hershey wrote:
Of course it might not make perfect sense to many....having two generators.
But like said above, the Honda uses a lot less fuel especially when doing the menial task like charging batteries. That alone may not save enough fuel to pay for the Honda, but its just so much quieter than my Onan...that makes it a done deal.

Makes perfect sense to me because I do the same thing for the same reasons.

hershey wrote:
My MH and I'd bet its similar to others will default to shorepower. So If the Onan is running and I plug into shorepower or my 2000 watt honda, it automatically switches to the shorepower/honda. Once the Honda is turned off, it automatically goes back to the Onan.

Mine defaults to the house generator anytime its running. So I can have the Honda running for normal house loads, fire up the house generator, do the MW, oven, etc. and kill it when done without going outside. The inverter picks up the qlitch switch of the ATS so the power is uninterrupted.