generator not charging batteries

**danlwil** · 05-23-2022, 02:50 PM

Went out this weekend on our 1st maiden boondocking trip and the batteries ran down
I ran the onboard generator for a good couple hours and it did not charge the batteries (12 v oem equipped interstate batteries)
I ended up plugging into the truck (ran it) and recharged the batteries enough to get me through the night without my fridge showing an error message

Am I doing something wrong or is the converter bad? (all breakers are on and the 40 amp fuses are good)

I would like to eliminate all possibilities before taking it in to the dealer ( their lead times are really bad right now)

thanks in advance
Dan

**Hoopy Frood** · 05-23-2022, 03:02 PM

How many batteries? What was the S(tate) O(f) C(harge)? What all were you running? What was the SOC before you left? What kind of refrigerator?

More information about what you own, what you pull with, and what appliances you're trying to run will help diagnose your problem.

**Soundsailor** · 05-23-2022, 03:17 PM

Originally Posted by danlwil

Went out this weekend on our 1st maiden boondocking trip and the batteries ran down
I ran the onboard generator for a good couple hours and it did not charge the batteries (12 v oem equipped interstate batteries)
I ended up plugging into the truck (ran it) and recharged the batteries enough to get me through the night without my fridge showing an error message

Am I doing something wrong or is the converter bad? (all breakers are on and the 40 amp fuses are good)

I would like to eliminate all possibilities before taking it in to the dealer ( their lead times are really bad right now)

thanks in advance
Dan

Hi Dan, sorry to hear this. It would help to know more about your coach. Which model? Have you successfully used the generator before? Does the generator run other things in the coach OK?

BTW, welcome to the forum.

**danlwil** · 05-23-2022, 04:15 PM

thank you for the replies

I have a 2022 25G Momentum toyhauler

2) 12 volt batteries (interstate deep cycle )OEM

it has an onan 4400 onboard generator
Solitude Solar System (300w Solar Panel, Controller, 1000w Inverter)
norcold 2 door fridge ( Model # N8DCSSL 12 volt only )

the batteries were fully charged when we set up (they charge fine off the truck alternator (2022 CHev 2500 HD)

We set up late Friday night
we used 12 volt system for interior and exterior lights, water pump and fridge.
the battery disconnects were on /the inverter was off
we were fine Friday night ( I wasn't monitoring battery voltage as I didn't suspect a problem)

I started the generator in the morning to make coffee and use the microwave. Ran about an hour or so. about 8:00 AM for 120 it works fine

By about 3 pm my wife noticed a beeping from the fridge and a E3 code.
I started up the generator and ran for about 2 hours but still had low batteries so I plugged into the truck with the 7 way connector and let the truck run for about a half hour
Immediately on truck start up the E3 code on the fridge went away...
I started looking closely and found all breakers to be on (generator too) and all fuses good
Continued to charge with the truck to get the batteries up enough give us little interior light ( I turned off the fridge for the night)

This was only a 1 day trip - I am going boondocking for 4 days over the 4th of July and hope I can get it all working by then.

Am I correct that the generator and solar (though the converter) charge the batteries? I suspect the converter is bad. Is there a method of testing it for output? If so, do I disconnect the batteries and test voltage in and out of the converter... If so, what voltage should it put out?

I hope this info helps... feel free to ask more if needed.

**stroguy** · 05-23-2022, 04:19 PM

With a multimeter at the batteries, disconnect from shore power and run the generator. See if a charging voltage of near 14 volts is present. If possible open the solar charge to the batteries.

**danlwil** · 05-23-2022, 05:32 PM

how do open the solar power?

**Hoopy Frood** · 05-23-2022, 05:41 PM

Is the solar power wired just to the inverter? And lead acid batteries take a while to recharge, a couple hours of running the generator won't do the trick. Probably 5 or 6 hours might do it. You need a reliable way to keep track of your 12V usage and battery charging.

**huntindog** · 05-23-2022, 06:07 PM

Originally Posted by danlwil

how do open the solar power?

I think he is saying to turn off or disconnect the panel.
My factory 300 watt system did not have a way to do this.

**danlwil** · 05-23-2022, 06:12 PM

suggestions on tracking the 12 usage?

**huntindog** · 05-23-2022, 06:17 PM

Originally Posted by Hoopy Frood

Is the solar power wired just to the inverter? And lead acid batteries take a while to recharge, a couple hours of running the generator won't do the trick. Probably 5 or 6 hours might do it. You need a reliable way to keep track of your 12V usage and battery charging.

A full charge will take a long time,,,, But he was able to limp along by plugging into his TV.

My money is on a converter problem.

OP: Is this the first time you camped in it?
A real common mistake when hooking up converter wires is to reverse the polarity. (yes even dealerships have done it) It is so common that there are fuses built into the converter that blow when this happens. Check them to see. If they are blown, correct the wiring, replace the fuses and go camping.

On edit: It is possible that it was reversed intially by the battery installer, caused a spark and the installer then corrected the wiring, thinking he got away with it. So your wiring MAY be correct now....The reason this happens so often is that the black wire is negative in the automobile world, BUT it is POSITIVE in towable RVs.