Fleetwood Saratoga battery problem

[Danyman]

Hello, I have a 2008 Saratoga popup trailer. Last summer everything worked great. I took the battery into my house for the winter & winterized the trailer.  This spring when I started to put it back into use I accidentally reversed the battery connection.  I forgot which way it went. Now it won't work on battery. It works when I connect my SUV, but not on battery.
What can I check?
The fuses on my converter are good.
The battery reads 12.4 volts.
Any ideas?

 

[Rene T]

When you plug into 110 volt ac, what do you read for voltage at the battery  terminals. You should be reading about 13.6 volts. Let us know what you find. If you?re reading just what you?re reading at the battery, you may have tripped the fuses on the converter. Some converters have fuses which protect the converter if you connect the battery cables on the wrong posts.

 

[Gary RV_Wizard]

You very likely popped "reverse polarity" fuses on the battery charger/converter, or possibly trip a breaker built into it.  I'm not familiar with the components used on your trailer, so hard to be specific.  Find the charger unit and identify the make & model; we can probably advise better/more once that is known.
If it has reverse polarity protection, there will be a pair of fuses, probably 30A, that are separate from the various 12v circuits. One or both blows instantly if the battery is hooked up incorrectly.

 

[Danyman]

When I plugged the trailer into AC I could see the battery voltage slowly increasing.  The open circuit voltage on the battery wires is 13.5. So I think my battery is OK and it's being charged.
But I still can't get anything to work 9n the battery. I'm suspecting the converter.  I have a WFCO Ultra Distribution Panel.
There are reverse polarity fuses which are good. I took them out and put my meter on them.
I'm still wondering why it doesn't work!!

 

[Rene T]

What you?re reading I think is the output of the converter which is good. What you need to do is unplug from shore power and take another reading at the battery posts. Tell us what you get.  It may be that your battery needs to be replaced.

 

[Gary RV_Wizard]

Maybe it will help if I explain what the various components do.

The converter/charger converts 120vac input to 12v power, typically about 13.6v  [Some converter/chargers have variable voltage algorithms for battery charging, but that's not relevant here.] The converter function supplies all 12v needs as long as 120vac shore power is available, and the charger handles battery charging at the same time.  You say that everything works when on shore power and that the battery is receiving 13.5v, so we know that the converter/charger is working and that is is delivery charge voltage to the battery.

Your problem apparently begins when you disconnect from the 120vac.  The converter can't supply 12v so the battery source is supposed to take its place.    The wiring that does that is internal to the WFCO power center.  Since you believe that the wiring to the battery is ok (as shown when 120vac is present), there may be a bad connection inside the WFCO.  You can open it up and try to fix, or you can replace the entire unit.

This brief manual may help:https://manuals.heartlandowners.org/manuals/Electrical/Converter/WFCO/WFCO%20Ultra%20III%20WF-8900%20Power%20Converter%2055Amp.pdf