Generator won’t charge batteries

[AlmostRetired]

I apologize if the answer lies within this forum. I searched for 20 minutes to avoid a redundant post.
I’m dry camping at a music festival for the next three days. The Onan will run everything just fine but it won’t charge the house batteries. I use a Yamaha 2k to keep the batteries charged since it sips fuel and it will charge the batteries so there is no urgent need for a remedy. The Magnum controller shows a fault warning but doesn’t get into detail. I did a soft reset on the inverter but no help. All breakers are fine except the washer/dryer circuit breaker won’t reset even with power off. I’m not planning on doing laundry while dry camping. Any ideas what may be preventing the gennie from charging the batteries? I just had the generator serviced and they replaced a circuit board for error code 14. Two weeks ago I was at another music festival dry camping and it started flashing 14 and shut off after a few minutes. Had a nice farmer camping next to me and he said to try loading the generator with both ACs and the water heater at start. Said they are meant to work hard and by golly, it fixed the 14 code. I called the service shop and the manual said to do the opposite and slowly add power. Didn’t work. Some more American heroes, Farmers! I have a 2016 ES 38PS3 with all the electronic safety options and AGS.

[Judge]

The Inverter should have nothing to do with your problem.

Not sure if you have a Use / Store switch but if you do are you sure it is in the Use position?

If that switch is in Store position, it bypasses the batteries and they won’t be charged by the genny or shore power.

If you start the engine, does that charge your batteries?

[AlmostRetired]

Thanks for your help. Seriously, I appreciate you. I’ve managed to go through life quite well even though I am the lowest common denominator in any group. What does the transfer switch look like? Single syllable words and/or pics are appreciated! Please type slowly...

[Judge]

Originally Posted by AlmostRetired

Thanks for your help. Seriously, I appreciate you. I’ve managed to go through life quite well even though I am the lowest common denominator in any group. What does the transfer switch look like? Single syllable words and/or pics are appreciated! Please type slowly...

I edited my post because when I re-read what you said I saw you did have AC power in your coach when the genny was running but the batteries weren’t charging. If you have some AC in the coach, the transfer switch is working.

After some more thought..... you might want to check the breaker for the converter. That should be in your breaker box.

The converter is what takes the AC and converts it to DC to run 12V accessories and charge the batteries when on shore power or generator power.

Perhaps when they were doing your generator work they switched off the converter breaker and never turned it back on?

[AlmostRetired]

Thanks, Judge. The breakers are fine except for the w/d. Don’t know why it won’t reset even without power. Must be a bad breaker. I’m not crippled while dry camping but it bugs me why the onboard gen won’t charge the batteries. Probably a reset or a loose connection but my background is with flesh and blood versus plastic and wires.

[Judge]

No worries......

When you get back It would be worth checking to see if shore power is charging your house batteries. If the shore power does charge them, then that would seem to indicate the converter / charger is working ok.

That would then start to narrow it down specifically to the generator circuit not getting power to the charger.

I have an Outlaw 29H Class C so they may be a little different but are you sure you don’t have a Use / Store switch? If I turn my Use / Store switch to Store, it disconnects the house batteries and they won’t charge.

[AlmostRetired]

The Yamaha 2k is simulating shore power at 20 amps. It charges the batteries just fine so I’m not in trouble the next few days. I thank you for taking the time to respond Judge, you must be a good man. Best to you and all you love!

[javelin]

You know what a lowest common denominator is and most of us are exactly the same, in at least one subject matter, so you are not alone. One of mine is that I don’t know your coach specific systems, but we will try to help anyway.
You said the gen runs your AC and DC loads OK. I expect your use/store switch is on to allow batteries to charge. What happens when you turn off the gen (with no AC shore power connected)....... do you still have your DC lights powered from the coach batteries? If not, you might have a tripped 50 amp re-settable breaker that is usually in series between the converter 12vdc output and the use/store latching relay connected to the coach batteries. The re-settable breaker is usually under the bed near the converter on many coaches.
You may also have a problem with the use/store latching relay. Do you hear a latching relay operating and releasing when using the use/store switch? Attaching a “generic schematic” showing this typical 50 amp re-settable breaker and the latching relay between converter and coach batteries to give you a rough idea of a basic battery set up. Also a picture showing what the small 50 amp resettable breaker looks like.

[Judge]

I missed you were running the Yammi as the shore power. I was thinking you were using it just to keep the house batteries charged via a separate charger.

Javelin may be into something. If that 50a breaker is tripped that would cause the issue as you look at the wiring diagram.

And no worries.... glad to try to help. Even though I don’t have the same rig a lot of the systems are very similar.

[AlmostRetired]

Thanks Javelin. I’m at the concerts for the night so I’ll respond in the morning. I’m drinking now and partying. I think I’m way too cute when I’m drinking. See you in the morning!

[AlmostRetired]

Thanks for the replies. I finally found the cause and thought I’d share it for someone else. I’m not sure if my pics will post so I’ll provide narration. The culprit was the Magnum AGS. The status button was flashing red so pushed the test button below it. The generator started and then shut off in test mode. Now, I couldn’t figure out how to stop the darn test mode and the status button was flashing green. Went inside to the remote controller and turned AGS off but the darn thing continued to test. Went back to the AGS with the flashing green light and pressed and held the test button for 10-15 seconds and it went to steady green and stopped the testing cycle. Everything is copasetic!

[Judge]

Excellent!

Thanks for reporting back and letting us know how you resolved it. Hopefully it stays that way!

Enjoy the music!

[AlmostRetired]

The saga continues but I’m happy for the moment. Turned off the main generator 5500W Onan, and started the 2k Yamaha since we were going to be at concerts. My wife came back early and the main generator was acting up again. Wouldn’t charge batteries or keep running. Batteries were at 12.0. The AGS controller was flashing green so I pressed and held it for 20-30 seconds and I could feel a click but it wouldn’t stay green. The small generator will not bulk charge batteries so I’m starting to panic. I had figured out every time I had issues it brought me back to the AGS controller. I pulled the fuse and voila’ everything is running again and I have AC for a hot, humid night. It’s my wife and my 24th anniversary at midnight and she thinks I’m her hero. It’s good to be me!

[Peterrrr]

I no longer have a Magnum inverter. What you seem to describe, is that you have AC power coming from your generator but no charge for the house batteries. There is a setting in the Magnum equipment which controls this. If I remember it is labeled , "Shore". If the power draw from your RV reaches what ever you have this option set at, then it decreases the amount of power supplied to the charge process. This could be your cause. I encountered the same problem in the past and it was this setting which corrected it.