Class A Generator and Battery ??

[jdub1177]

Hi All, I've been a member before, but can't seem to remember my old log in.

Love the site, very helpful!

Anyhow, need to draw on the knowledge base. 🙂

Have an Onan Diesel Generator that is throwing a Error Code 25 (governor issue). Basically fires up, runs for 20 minutes, slows and surges, than dies. Runs great when coach engine is also running?? Was recently serviced (oil change and fuel filter).

Called Onan, they think it may be a voltage issue. I was just wondering if anyone has had this experience and was it their house batteries? Previous owner said the house batteries are only 2 years old.

We purchased in July

2010 Fleetwood Discover 40g
Onan Quiet Diesel with 900+ hours

I have not tested the batteries yet, not really sure how or what I should want to see...

Thank you in advance!!

[jdub1177]

Latest:

Replaced all 6 batteries, same issue. Generator shuts off after 10 to 15 minutes, and throws a Error Code 25...

Eliminated bad batteries....

Thank you in advance! 🙂

[jdub1177]

Update. In order:

Unplugged

Kicked on 6 lights only, inverter/converters were off.

Turned on furnace.

Within 15 minutes Coach battery guage reads 11.9....

Toast? 😉

Thank you!

Joe

[D_E_Bishop]

Another thing that could cause those symptoms is, lack of fuel. My Bounder had a very weak in tank fuel pump and the engine would loose power after running at high speed for awhile. Could be the fuel pump on the generator can't keep up with the demand if the engine is off, with the engine running the in tank pump would be helping the generator pump.

If the problem continues after replacing the batteries(if needed) it would be something to look at.

[MrWizard]

12.8 or more
Is correct for fully charged batteries freshly unplugged
Your batteries need to be replaced
If plugged in all the time
Fluid level in batteries should be checked at least once a month

[jdub1177]

Thank you Fred!

Yes I did fill the batteries once I noticed they were dry.

Great advice, I will work on it and report back.

Based on your notes though, I remember seeing 12.4 almost immediately after unplugging.....I suspect I cooked them.

If keeping it plugged in when not in use will cook the batteries, what do you recommend? We like to keep a dehumidifier going and typically don't shut the fridge off...

[Golden_HVAC]

Yes dry batteries can cause the problem.

I guess that you have filled the batteries? If not do so with distilled water.

Once the battery is full, try this. Check the voltage while it is plugged in. Should be in the 13.2 to 13.8 volt range. If over 13.8, it will lose water much faster than normal, and you need to keep adding water monthly.

Then unplug the coach and turn on some lights to put a load on the battery. It should drop to 12.8 or 12.7 (indicating full batteries) fairly quickly, then good batteries will slowly drop to around 12.6 and later (an hour or two later) might drop to 12.5 volts. Bad batteries might drop to 12.5 in 10 minutes and 12.2 in 2 hours with only a few lights on. Run the furnace, and that load can take a bad battery to 11.9 in a hurry.

If the battery gets to 11.9 volts within 3 hours, I would be replacing them, they are done. If you put a load on them like 'normal camping' with 3-4 lights on for a couple of hours, then shut them off, go to bed, and in the morning turn on a couple of lights, the voltage should be above 11.9 in the morning. Otherwise the battery will not support a normal camping trip, and should be replaced.

Also check the battery voltage while the generator is running. If you are getting 13.2 volts when on shore power, you should be getting 13.2 volts on generator power, and perhaps a little more if the inverter/charger has restarted and now is in the 'bulk' mode, it might be putting out 14.4 volts.

IF the generator is shutting down because of high input voltage from the battery, perhaps the inverter/charger or generator voltage should be adjusted. Perhaps the inverter/charger is putting out to high of voltage, or the generator is to sensitive to getting 14 volts to it's battery connection.

You should also be checking the generator output 120 volt too. It might be the generator output is going over 130 volts, and shutting it down too.


Good luck!

Fred.

[ksg5000]

Most auto parts/ tire outlets will load test your batteries for free - that should rule out batteries as issue.

[jdub1177]

And the inverter/converter display(s) will say "absorb" when Genset is running.

[jdub1177]

Good info, let me add some more information now that you reminded me. I needed the generator when we had some weather and lost power to house, so we were gonna driveway camp. That time, the batteries were about 70% charged. Power came back on to house, so I plugged the coach back in, fully charged all batteries, unplugged, fired up genset, same symptom.... In addition, I'm the type to keep my rv plugged in when not in use, I didn't think to check water level in batteries, when I finally did, theY were DRY! Worried I may have cooked the batteries?

The voltage Guage shows 12.4 when freshly unplugged. Over 13 when Genset is running.

[MrWizard]

check the voltage on the batteries
before starting the generator and with the genset running
the converter/charger (maybe inverter-converter combo) should be charging the batteries
sounds like it is turned off or malfunctioning
could be a switch or fuse or even a "breaker/reset" on the "converter"
or a GFI that supplies the converter circuit and is tripped,
no power no charge.. the batteries are low and cannot maintain voltage to the genset

[Crazy_Ray]

Check btry with volt meter 12.6+ fully charged. Google 12 volt side of life and read learn, GREAT READ