House batteries Charging

[KevinjmAZ]

New to us a 2019 Winnebage outlook, 27D. First time dry camping. Fridge is electric only running on an inverter. (I have read some of the tips like shutting down at night and learned for future but my question is more about charging system.)
1st night was colder so ran furnace along with the fridge. The Battery indicator was at the Low mark. Was able to start the house generator but no sign of any charge. Ran for 2-3 hours. Later the generator wouldnt even start due to no power. Multimeter shwed 10 v and falling. Attached a 2000W generator and ran for about 8 hours with no charge. Started the coach and immediate charge indicated. Drove home for 1.5 hours and the batteries show 12.5 volts with enging off. Show 13.9 with coach engine running and charging. But when plugged into shoreline back to 12.5 with no indication of charging. What am I missing? Thanks

[Morich]

Several small points that can be simple but also very confusing!

Your RV has a newer system for doing called BIM (battery isolation manager) . It has replaced what was called a "mode solenoid"on older models but they do pretty much the same but solenoids are an electrically operated "switch" that closes contacts. The Bim is a solid state item which doesn't have the solenoid and has done away with contacts to go bad on solenoids!
Simple and likely work better but less user friendly for repair!

Basic operation?
When camped, the coach and chassis 12VDC systems are seperated. When plugged into power or generator running, there is some form of charger connected to the coach batteries to charge them. Older were converters and only did the change from AC to dc for charge. Then inverters were added to use battery to make DC. Without looking, I would guess you may have a inverter/charger/ automatic power switch!

But they all should do the same on the separating/combining of the two 12VDC systems and batteries.
Plugged in, the coach gets charge but not the chassis, so you can get the chassis battery run down at times. When you need a jump start or boost to get the engine running, you have a switch near the driver which they can push to momentarily connect the batteries together. Bim and solenoid do the same but different equipment.

At the same time there is a connection to a portion of the chassis wiring called igniton hot. When we have the key on and this wire is "hot" the two systems, BIM or solenoid should connect the batteries together. This is when we expect to get a bit of charge back into the coach as we drive.

The place things get confused is when we try to read voltage as we will not get a true story if we miss a few points!

While we have charging from any source and read a battery, we see the voltage high and think it good but that is only the charger sending that voltage and DOES NOT mean the battery is getting or holding that charge!

Charging is a sloooow chemical process that takes hours to go from flat to near fully charged and a fully charged lead acid battery will never hold more than 12.8 volts. Just the way it works, so when you see higher, you are seeing what we call surface charge or the charger itself!

To get a betteridea of charge we have totake the charge off and wait a few hours for the chemicals to settle!.

Several points to help for future. When wanting to charge a weak coach battery, start the RV engine first. The coach battery may be weak and it is where the generator gets power to start, so may fail! But if you start the engine which we are assuming to still be good after camping, then the engine alternator is working to give lots of power to the chassis battery and the system should automatically connect it to the coach battery and that is a lot of power to let the generator start even if you have to crank it for a few tries!
Once the generator is running, it should then be charging the coach batteries and we can shut down the engine and alternator as no longer needed!

Maybe that will clear a few questions of what SHOULD happen, but there may be a problem if the coach batteries ran down while plugged in as that would mean the power is not getting from the charge portion for the inverter/charger or whatever they currently call what you have!

I suggest this for testing.
Start the RV engine. This should give good power to both sets of batteries to show they are connected. Reving the engine may give you 13.5 or higher as the alternator is pushing a charge to both sets!
This can be vital as the next step is to try turning the coach battery disconnect off and back on. This switch sends power to a relay and that relay has to have good coach battery to move and close! A magnet holds this relay in the last position. If we turn the disconnect off and the battery is down, we can't get it turned back on----until we get good coach power to move that relay!
See if all is better when the engine is started first as a way to get good power to it all until the battery gets in better shape.

But if you are plugged in or the generator is running, either should be powering the charge for the coach batteries. If you get the engine running, start the generator and let the genset run as you turn off the engine. Killing the engine will drop that charge coming to the coach batteries and let the generator and charger do that? Look to see there is still a high voltage showing on the coach batteries as they SHOULD be getting charged.

If the voltage still shows not charging like 13+, there is a problem between the charger and batteries to check out.

See if that helps and shout back as this is one of the more frequent things we discuss around here!

[Morich]

Sorry, tried to mislead you as you do have the solenoid, not the BIM!
They are located as shown here from the parts drawings:

https://catalog3d.winnebagoind.com/menu/Parts.htm

Click these snips to get a better view!



As a help to ID which cable goes to what, there should be tape markers on the cable ends to match this.



I find the solenoid is easier to work as I can hear and feel it move! If it is quiet around you and you push the dash switch, you may hear it thump as it closes or if you lay a hand on it while somebody else pushes the switch, you may feel it!
That will mean it is trying but the contacts inside can get burned/corroded and not actually make the connection. One way to test the solenoid without actually going to it( if it's hard to reach) is to test the two battery groups voltage and without starting the engine, have somebody push the button and see if the two voltages then match, showing they are connected.
OR
Start the engine and see if both battery voltages jump up high when the engine is started and revved up!

[KevinjmAZ]

Thanks for the details and the fast response. I have looked in the battery area and it is exactly as you show here. I will do the testing you layed out and if I am reading it correctly, the most likely problem is the solenoid and not the relay.
Like to pick your brain just a bit more. The panel lights show L-F-G-C. Does the "C" stand for "Charged" or "Charging" ? When running main engine all 4 are lit but when on shore or generator the "C" is not longer lit up.

THANKS AGAIN,
Kevin

[Morich]

Takes time for me to get a better idea of what you have and it helps if I look first and THEN answer! Electronics on our RV are changing all the time, leaving me behind!

To test the solenoid can be easy if you have a meter. There are two big cables on two big lugs on each side of the solenoid. Those cables should be labeled and one goes to each set of batteries. If we look at the voltage on each, at the solenoid or at the batteries, we will usually find a different reading on coach and chassis, if we have not been charging recently.
If we then push the switch or start the engine, the solenoid SHOULD connect them and we SHOULD see the same voltage on each! This is assuming the cables are clean, not corroded and that being the real problem!
NOTE:
Don't be shocked if you find a solenoid that works one day but not the next as it sometimes gets down to being two rusty pieces of metal slapped together and sometimes they make contact and sometimes not!
The solenoid arcs every time we start the engine and that makes it wear out sooner than we like. Maybe ten-fifteen years? But the corrrosion and dirty cables seems to happen every fifteen DAYS!!
Check for bad connections first!

When looking at the solenoid, they come in two types, one small wire or two. Some have only the batttery signal from the front and others both battery and ground using two wires. The two wires can be more reliable as the single wire type uses the metal connection of the mounting screw as ground. Make sure that metal connection is clean and solid if you have a single small wire. If the mounting screw gets loose or dirty, the solenoid gets funky and may not move!
Three post:
https://www.amazon.com/May-Continuou...87555298&psc=1
Four post?
https://www.amazon.com/Cole-Hersee-2...76528814&psc=1


On a solenoid that is way back somewhere out of reach, I go for hearing it move, rather than tear a bunch of stuff out to check the connections.

On reading the lights, I have no idea and would referr to the manual for that panel. Do you have a set of books in a big folder with manuals for a lot of the small parts of the RV?
I might start the search there and if not on hand, try looking for the brand and model number of the display?

[powercat_ras]

Additional discussion:

As a 2019 Outlook, it may still have the original OEM batteries which are now 3-4 years old. Winnebago used inexpensive NAPA RV/Marine batteries in these units and they are subject to loss of much of their storage capacity in 3 years. So one thing is you may need to replace them. If you do don't use RV/Marine batteries again. You want to use true Deep Cycle batteries. If you measure where the batteries are and there is enough height for them Golf Cart batteries are your best bang for the buck. If there are two coach batteries wired in parallel your best bang for the buck is to replace with two 6V golf cart batteries wired in series. If you have or know someone with a Costco membership and can handle the height this is about the best cost/value solution there is: Costco 6V Golf Cart Battery

[KevinjmAZ]

More to the story and wonder if on right track? The solenoidengages/disengages when disconnect when toggled. Pulled the cover and looked at the converter (8955PEC180326) and no obvious issues but when the service disconnect is turned back on the converter fan only runs 1-2 secs and then turns off. Converter? Search shows the 8955PEC - as a "WF-8955PEC Converter/Charger 55 Amp Power" and ignores the last 6 numbers. I admit I am mildly handy with electrical being the weakest link. Thanks