Battery overcharge

dvdockery2

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Joined
Aug 11, 2024
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2
Location
Elberton
We have owned a 36 ft motorhome and a 36 ft 5th wheel, and recently downsized to a 22ft travel trailer (Coleman CM1805RB20).


Got it home, plugged into our 30amp camper service line and later found the battery hot and bubbling over. After multiple attempts of cooling the battery, adding water with electrolytes (there was evidence this was not the first time it had boiled over), we looked for a disconnect like our other campers had -- that disconnects the battery from the charging system. NOTE: the battery did not overcharge during the 3-hour trip home connected to our pickup.


Can't find a disconnect. Can't find the converter. Can't leave the battery connected. Don't have the original owners manuals because we bought it used.


It looks like everything works on shore line with battery disconnected. Just hate to not have a working battery in case of emergency.

Any suggestions?
 
Last edited:
Sounds like you are trying to charge a shorted battery. You are lucky it didn’t explode! I suggest changing the battery, plug it in and check the amount of voltage to the battery when charging. You should have 14 or so volts.
 
22ft travel trailer (Coleman CM1805RB20).

Got it home, plugged into our 30amp camper service line and later found the battery hot and bubbling over.


This indicates a shorted cell inside the battery. Battery charger keeps tying to bring the voltage up to 13 volts or so. Battery with shorted cell now is a 10 volt battery. Heat and acid spitting is the result.

Replace the battery.

we looked for a disconnect like our other campers had -- that disconnects the battery from the charging system. NOTE: the battery did not overcharge during the 3-hour trip home connected to our pickup.

Can't find a disconnect. Can't find the converter. Can't leave the battery connected. Don't have the original owners manuals because we bought it used.


Battery disconnect switches are usually after market. RV builders rarely put a disconnect switch in. Battery must not be disconnected while towing for safety purposes. Electric emergency brake requires 12 volts in case trailer becomes disconnected from tow vehicle.

Any automotive store will sell battery disconnect switches. Even Walmart probably stocks battery disconnect switches in the automotive section. Dozens of them are listed on Amazon.

Inverter/Chargers, or Converter Chargers come in many different configurations. Mine is built into the main circuit breaker panel.

Some are deck mounted and connected with wires and fuses.

Sometimes you can find it by following the wires from the positive terminal of the battery or from the main 12 volt fuse panel.

"It looks like everything works on shore line with battery disconnected. Just hate to not have a working battery in case of emergency."


RV's with converter/chargers often provide good 12 volt power to 12 volt appliances when the battery is disconnected. Mine does.

Do you have an inverter?

What is the make and model of the main circuit breaker panel?
 
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Battery overcharged

Thanks for all the comments. We tried a different battery and it is working fine. Apparently it was shorted.


We found the converter; built in with the breaker panel. Our previous RVs had factory battery disconnects, but this one doesn't, so we will be adding one. As far as we know it does not have an inverter.



We are now Happy Campers!
 
Thanks for all the comments. We tried a different battery and it is working fine. Apparently it was shorted.


We found the converter; built in with the breaker panel. Our previous RVs had factory battery disconnects, but this one doesn't, so we will be adding one. As far as we know it does not have an inverter.



We are now Happy Campers!

As Persistent noted, make sure your disconnect does not impact your emergency brake as that will need power to activate if the pin pulls. Same with any running and brake lights, which should work off of the tow vehicle battery but double check that everything works when the disconnect is off.
 
Maybe Cheap Chinese Converter

Persistant Hates it when I chime in. Many converters in RVs are from WFCO. They are notorious for not only slowly charging batteries, they overcharge them.
 
Battery

We have owned a 36 ft motorhome and a 36 ft 5th wheel, and recently downsized to a 22ft travel trailer (Coleman CM1805RB20).


Got it home, plugged into our 30amp camper service line and later found the battery hot and bubbling over. After multiple attempts of cooling the battery, adding water with electrolytes (there was evidence this was not the first time it had boiled over), we looked for a disconnect like our other campers had -- that disconnects the battery from the charging system. NOTE: the battery did not overcharge during the 3-hour trip home connected to our pickup.


Can't find a disconnect. Can't find the converter. Can't leave the battery connected. Don't have the original owners manuals because we bought it used.


It looks like everything works on shore line with battery disconnected. Just hate to not have a working battery in case of emergency.

Any suggestions?
I would suggest pulling the battery and have tested at a auto parts store:)
 

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