Gen - How long will it run?

Me.Bikes.Dogs · 06-25-2011, 06:30 PM

Anybody know about how long the Onan 5,500 Watt Generator will run on 30 gallons of gas? Haven't used it much but boondocking tonight and it's 100 degrees outside. With the gen. running I can run the A/C thankfully. Thanks!

Me.Bikes.Dogs · 06-26-2011, 04:16 AM

Answer my own question, used 1/4 tank in 12 hours. Tells me I have about 48 hours of generator. Good to know.

**JRTJH** · 06-26-2011, 09:05 AM

HOLY SMOKES !!!!!!!!!!!!!! 7.5 gallons in 12 hours? That's 0.65 gallons an hour. That's a pretty thirsty generator !!! Of course it's 5500 watts, a little bigger than most of the "quieter" portables, but still thirsty !!!

Our Champion has a 4 gallon tank, we can run about 12 hours with the A/C and converter running. We leave the refer and water heater on gas and occasionally use the microwave, but mainly for the A/C and recharging batteries for when it cools down. Thats about 0.3 gal/hr, about 50% less.

Have you actually refilled the gas tank and hand calculated the run time or are you just "guesstimating" based on the fuel guage? It might be better than you think

antiqfreq · 06-26-2011, 12:15 PM

Our Honda Eu2000's run about 7 hours filled up with the a/c cranking.....

Had to use them sometimes when we were drycamping out west and it was really hot!

Jo

**JRTJH** · 06-26-2011, 02:42 PM

Quote:

Originally Posted by antiqfreq

Our Honda Eu2000's run about 7 hours filled up with the a/c cranking.....

Had to use them sometimes when we were drycamping out west and it was really hot!

Jo

Then that's 1.1 Gal per generator for a total of 2.2 Gal for 7 hours for 4000 watts (max) or a burn rate of about 0.3 Gal per hour. Not bad and about the same as our champion.

Me.Bikes.Dogs · 06-26-2011, 07:17 PM

That was guesstimating using the gauge. I know they can be off pretty wildly. On my bike the first quarter tank takes forever to run down and the last 1/2 flies by really fast.

I've never used a generator before. I was under the impression that it ran at one speed and produced it's peak wattage at that speed. I would think fuel efficiency wouldn't be connected to the devices running, am I incorrect?

Txoutback · 06-27-2011, 03:32 AM

Quote:

Originally Posted by Me.Bikes.Dogs

I've never used a generator before. I was under the impression that it ran at one speed and produced it's peak wattage at that speed. I would think fuel efficiency wouldn't be connected to the devices running, am I incorrect?

THe lightweight genny's run at 3600 rpm. The fuel consumption is directly proportional to the amount of load applied just like your TV. Running your gas TV at 6o mph without the TT and you may get 18mpg whereas driving the same road at the same speed with the TT connected you may get 10 mpg. A genny is the same way. The efficiency rating is a non-linear curve meaning the more you load it the less efficient it is KW/gal. Diesel gennys are more linear and efficient but heavier and smaller output units are less common.
Side note: I have found with my champion that if I turn on the AC and let it run for about 10 minutes I can turn on my water heater without killing the genny as long as the AC compressor stays on. If I let the compressor cycle off and then back on it overloads the genny and I have to start over. The AC startup current with the water heater on exceeds the genny ability.

antiqfreq · 06-27-2011, 04:22 AM

Even though we have the generators we use the refrig and water heater on propane only - we don't use electricity for those unless we are in a campground with power & then we don't need the gens anyways.

On a side note, gotta turn off a/c to run the microwave, OR else those gens SCREAM........

Jo

**JRTJH** · 06-27-2011, 09:05 PM

Quote:

Originally Posted by antiqfreq

Even though we have the generators we use the refrig and water heater on propane only - we don't use electricity for those unless we are in a campground with power & then we don't need the gens anyways.

On a side note, gotta turn off a/c to run the microwave, OR else those gens SCREAM........

Jo

antiqfreq: are you saying that running 2 honda 2KW generators that you load them down with the AC and the microwave? We have teh 4KW Champion, Dometic 13.5K AC and a 900Watt microwave and the AC will start while the microwave is running and the generator doesn't seem to load up much at all. The honda is rated 2KW max and 1.6KW continuous, so 2 in parallel would be 3.2KW continuous, the Champion is 3.5KW continuous, I wouldn't think 300 watts would make that much difference. How powerful is your microwave?

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