12 volt power issues

[tonythepony]

Got up yesterday to find 12 volt power like all 12 volt lights barely working and finally stopped I was plugged in to 50 Amp shore power.
Also 110 volt outlets were only working at partial power.
Reset all 110 breakers even though none were tripped
Power came back on 110 and 12 volt systems.
What would cause that?
Also house batteries will not charge on shore power I have to keep a battery charger on them that I keep plugged into one of the outside outlets on the RV
Think it’s all related??
2010 Montana Mountaineer 37 ft bunkhouse

[firestation12]

Originally Posted by tonythepony

Got up yesterday to find 12 volt power like all 12 volt lights barely working and finally stopped I was plugged in to 50 Amp shore power.
Also 110 volt outlets were only working at partial power.
Reset all 110 breakers even though none were tripped
Power came back on 110 and 12 volt systems.
What would cause that?
Also house batteries will not charge on shore power I have to keep a battery charger on them that I keep plugged into one of the outside outlets on the RV
Think it’s all related??
2010 Montana Mountaineer 37 ft bunkhouse

You’ve not provided enough info to get a simple answer. I’d suggest you start at the batteries. If they have been depleted to where the lights quit working, consider replacing them, regardless of age. Consider installing lithium batteries. Amazon for example has Chin branded lithiums for just over $300 each. The battery protects itself from over discharge (as does most lithiums). The second item to investigate is the voltage converter. If the 12 volt lights stay on with the batteries disconnected, then the converter is working. You don’t state how you determined the 120 volt system was working at “partial power”. BTW using the term 110 volts casts doubt about this. The only link between the 12 volt and 120 volt systems, is the voltage converter. If your batteries were toast and the shore power suffered a “brownout” then yes you could have had the symptom you described. Had an EMS such as the Progressive PT50X been in place, it could have diagnosed and stored a trouble code. An EMS can prevent damage to all your electrical devices….A/C, microwave, radio etc.

[DQDick]

First check your converter. On a 12 year old rig it could certainly be going bad and flipping its breaker may have given it a jolt to restart working. As far as charging the batteries, make sure your battery disconnect is in the proper setting. If you can remove the key it's off and the batteries won't charge. Do not change to lithium batteries as your converter isn't made to charge them, they weren't even invented back then.

[Daryles]

Carl wrote this 12vdc troubleshooting flow chart:
https://www.montanaowners.com/forums...ad.php?t=86323

[firestation12]

Originally Posted by DQDick

First check your converter. On a 12 year old rig it could certainly be going bad and flipping its breaker may have given it a jolt to restart working. As far as charging the batteries, make sure your battery disconnect is in the proper setting. If you can remove the key it's off and the batteries won't charge. Do not change to lithium batteries as your converter isn't made to charge them, they weren't even invented back then.

Actually lithium batteries can be charged from a standard OEM voltage converter.
There is ample evidence that charging lithiums at say 13.6 volts instead of 14.4 volts extends the lifespan of the battery.
Here is a screen shot from Battle Born presentation.

[tonythepony]

Originally Posted by firestation12

You’ve not provided enough info to get a simple answer. I’d suggest you start at the batteries. If they have been depleted to where the lights quit working, consider replacing them, regardless of age. Consider installing lithium batteries. Amazon for example has Chin branded lithiums for just over $300 each. The battery protects itself from over discharge (as does most lithiums). The second item to investigate is the voltage converter. If the 12 volt lights stay on with the batteries disconnected, then the converter is working. You don’t state how you determined the 120 volt system was working at “partial power”. BTW using the term 110 volts casts doubt about this. The only link between the 12 volt and 120 volt systems, is the voltage converter. If your batteries were toast and the shore power suffered a “brownout” then yes you could have had the symptom you described. Had an EMS such as the Progressive PT50X been in place, it could have diagnosed and stored a trouble code. An EMS can prevent damage to all your electrical devices….A/C, microwave, radio etc.

12 volt batteries were at approximately 90% charge according to my gage
Battery charger was only showing 5.8 volts charging ( normally at 12-13 volts. 12 volt lights were on but very dim
A/C kicked on then right back off
Jacks and slides would not make a sound
Battery charger was plugged in to outside plugs on camper
Only after I reset all shore power breakers inside the camper fuse box
After all were flipped off and then back normal 12 volt and 110 shore power worked fine

[tonythepony]

Where would the converter be located on my 2010 Montana Mountaineer?
I don’t think my batteries are being charged while plugged in to shore power.
When I get back to the camper I will check the battery voltage plugged in to shore power and then unplugged
The battery charge indicator inside the camper continues to go down plugged in to shore power when using the 12 volt system including lights and water pump.

[jimcol]

The partial power is confusing. Your fix leaves the possibility one side of your 50amp breaker was tripped even if it didn't look like it. The side that was tripped also controlled the 120 volts to the converter. Or, the breaker feeding the converter was tripped.

[BB_TX]

Just to make sure you are aware. Circuit breaker handles do not flip to OFF when tripped. They just move slightly from the ON position. Not always obvious by just looking when one is tripped. If a breaker is tripped and you push the handle toward the ON position you will feel it move a fraction of an inch with a “soft” feel. OFF to ON resets it.