I have an Onan 7500 watt diesel generator.With nothing on in the motor home, other then then items like the CO2 detector, the Microwave display, etc etc. the following is happening.The generator will run at three different rpms (judging from the sound) At each level it will run for several minutes (5-10) then will switch to the next level. Kinda like shifting gears.Inside the motor home I have a Xantrex display that shows DC Volts, amps and Battery State.The Battery State displays 3 different battery levels. First indicator is an outline of a battery and shows a low level, next little battery shows a 1/2 level and the 3rd battery display shows a full battery.When the generator changes rpm (power) the Battery State display will change also. I don't recall my generator doing this before.I did check the voltage at the batteries at they were all good.Any ideas?ThanksBrian PS This is on a 2004 Fleetwood Revolution.

As it changes RPM levels, are they decreasing? If so, is it following the lower power demand as battery charging amps drop?

I suspect you are experiencing battery failure.Have your batteries load tested.Richard

Buy one of the inexpensive Kill-A-Watt meters and when your generator is running, this will tell you the exact voltage and frequency of your generator output. it should be a constant 120 volts at 60 cycles. Kill-A-Watt

I have a 2005 Fleetwood Excursion with the same generator. With nothing else on, the generator rpms will change and the needs of the batteries / battery charger change. The rpms will start off somewhat higher when the batteries first start charging - drawing a higher amperage. Then as the batteries have been receiving a charge, the charger amperage decreases and therefore the generator rpms decrease.I don't see any problems with your generator. The same thing happens when the A/C or microwave comes into use.Bill

Trackrig wrote:I have a 2005 Fleetwood Excursion with the same generator. With nothing else on, the generator rpms will change and the needs of the batteries / battery charger change. The rpms will start off somewhat higher when the batteries first start charging - drawing a higher amperage. Then as the batteries have been receiving a charge, the charger amperage decreases and therefore the generator rpms decrease.I don't see any problems with your generator. The same thing happens when the A/C or microwave comes into use.BillThanks Bill, the trouble is, it will keep going through these cycles, over and over and over again.

Generator run at different speeds | Good Sam Community

rgatijnet1
Explorer III
Oct 04, 2017
The sound of the generator will change as the load increases or decreases but the RPM's are what determines the 60 cycle AC output. The RPM's should remain constant, with a small jump as the load changes.
supercub
Explorer
Oct 04, 2017
Trackrig wrote:
I have a 2005 Fleetwood Excursion with the same generator. With nothing else on, the generator rpms will change and the needs of the batteries / battery charger change. The rpms will start off somewhat higher when the batteries first start charging - drawing a higher amperage. Then as the batteries have been receiving a charge, the charger amperage decreases and therefore the generator rpms decrease.

I don't see any problems with your generator. The same thing happens when the A/C or microwave comes into use.

Bill

Thanks Bill, the trouble is, it will keep going through these cycles, over and over and over again.
Trackrig
Explorer II
Oct 04, 2017
I have a 2005 Fleetwood Excursion with the same generator. With nothing else on, the generator rpms will change and the needs of the batteries / battery charger change. The rpms will start off somewhat higher when the batteries first start charging - drawing a higher amperage. Then as the batteries have been receiving a charge, the charger amperage decreases and therefore the generator rpms decrease.

I don't see any problems with your generator. The same thing happens when the A/C or microwave comes into use.

Bill
rgatijnet1
Explorer III
Oct 04, 2017
Buy one of the inexpensive Kill-A-Watt meters and when your generator is running, this will tell you the exact voltage and frequency of your generator output. it should be a constant 120 volts at 60 cycles. Kill-A-Watt
RLS7201
Explorer II
Oct 04, 2017
I suspect you are experiencing battery failure.
Have your batteries load tested.

Richard
wolfe10
Explorer
Oct 04, 2017
As it changes RPM levels, are they decreasing? If so, is it following the lower power demand as battery charging amps drop?

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