Can't get my gen to charge batteries above 12.5v

[YC1]

Gen shuts off at `12.5v instead ot 14.1 like it is set at

What does that mean? Does the generator shut down? Are you using the auto generator start function and having issues?

The generator should be just like connecting to shoreline as far as charging is concerned. If you are running the generator for short periods of time there is no way it will fill a large bank of batteries in less than two hours.

[jollyjim]

We had a similar problem that defied attempts to diagnose it. Turns out it was the temperature sensor that is placed on the side of one of the batteries to adjust the charge rate based on temperature. The sensor or the wiring was bad. When the sensor was disconnected from the inverter it imediately began charging at a resonable rate. You may want to try disconnecting the sensor from the inverter and see how it works for you. Would be curious to find your results. Good luck.

[Cat320]

The problem could be the Magnum. You have an odd number of batteries (6)...most have four or eight. You could try increasing the charge rate...it's under "settings'' on the Magnum. The other thing to check is where the "absorb charge" is set. My Magnum 'thought' there were only four batteries so it had an absorb rating of 1.5 hours. With eight batteries, the tech said to raise it to 3.0 hours. So with the charge rate increased to 80% or 90% and the absorb rating increased, all is well.

[dpinvidic]

Originally Posted by pointrow

Up date: Moved to shore power and battery voltage jumped up to 14.1 and full bars for full batteries. On the road 13.5v the same as on generator. So the dc charging system is suspect.
FW thinks it is the Ohnan Generator at fault but why wouldn't the engine alternator charge the batteries full?

Wanted to point this out from the OP. There is nothing wrong with the magnum since it works fine on shore power.
I know this thread is long, and some folks are skipping important posts

We need more input from the OP after a few more checks.

Regards,

Dan

[Kro1957]

Some of this has already been discussed. Like load with shore power.

Not being a electrical whiz I would want to isolate or find varied readings.

With all power off, no input or output. I would take my meter and read both engine bank and coach bank batteries. They should be in the 12.5 12.6 range.

With engine running, the alternator should be putting out 14.2 - 14.7v range.
(I think there is an adjustment if it is out of specs)

I think the genset might put out slightly higher voltage. I do not remember.

Do the same process with shore power as you did already, and with the gen set.

I would also do this as a periodic pre/post trip and record readings in your log book.

If it is isolated just to the generator, my next guess might be to pull the cover on the transfer switch and take a reading at your posts with it running and see what is coming back there.

Electrical is always challenging. Let us know what the resolve was!!

Good luck!!
James

[pointrow]

Thanks everyone for the ideas.

I talked to the Magnum tech support and they ran me through the settings and changed a few. I learned a lot talking with them.

I won't be able to do further testing until I'm back home where I can run the gen for an extended time in late April.

This has been one of the most helpful and civil discussions I have ever had on here.

Thanks
pointrow

[Kiawah]

Suspect it's your Magnum AGS (auto generator start) configuration settings which are set when to shut the generator off.

[Cat320]

Originally Posted by pointrow

Thanks everyone for the ideas.

I talked to the Magnum tech support and they ran me through the settings and changed a few. I learned a lot talking with them.

I won't be able to do further testing until I'm back home where I can run the gen for an extended time in late April.

This has been one of the most helpful and civil discussions I have ever had on here.

Thanks
pointrow

Magnum does not know how your coach is wired...I'd give FW a call and see what they say.