Forum Discussion

SamAnne's avatar
SamAnne
Explorer
Aug 15, 2019

Trickle charger for batteries

1. Monaco Vesta 2012: Wonder if there was ever a trickle charger put on this RV? If batteries are pulled out, will there be something in that area that will show me it? I have been told to disconnect it and install a new one. My chassis batteries boiled over terribly; I replaced 3 years ago and now have noticed it has boiled over again.
At a suggestion from a heavy duty mechanic, we replaced the batteries 3 years ago and I stopped leaving RV plugged to shore power when not in use; I also turn off the Inverter. The batteries are always ready to go if I don't let it sit over 4-5 weeks. I do shore power for 24-36 hours when I do plug up in storage.
2. This all came to light when Onan Generator would cut off shortly after starting. Onan repairman said I need to check my electric so we thought checking the batteries would be good. Getting to the generator battery seems difficult so we started with the Chassis and House batteries. Any suggestions greatly appreciated. Also, what does Subscribe,do not....all that mean?
Class A
  • Sam_Spade's avatar
    Sam_Spade
    Explorer
    Aug 15, 2019
    You need a voltmeter.
    To check the charging voltage under various conditions.

    This sounds very much like your converter/charger has failed.
    A more sophisticated one should solve the problem.....but if it is only off by a little bit.....you can certainly unplug the shore power cord and manually connect an automatic smart battery maintainer instead while it is in "storage".
    You do NOT want anything that is labeled as a "trickle charger".

    P.S. Although somewhat more expensive, AGM batteries are usually a better choice as they are maintenance free.

    And finally, if you have a 12 V power socket available that is connected to the house batteries, I find that having a digital voltmeter plugged in there allows you to monitor the situation, more or less continuously.
  • msturtz's avatar
    msturtz
    Explorer
    Aug 15, 2019
    Most motorhomes have a combined inverter converter. Usually they are made by Magnum Energy or Xantrex. They charge the battery when connected to shore power. Most of them are configurable first battery type (flooded, AGM, gel) as well as any equalization requirements. If the inverter/converter charger fails for some reason it is possible that the voltage is too high causing the batteries to boil. I would check the open circuit voltage when on shore power with everything but the charger off. Then test again with the batteries connected. If you have a higher voltage than 13.8 with the batteries fully charged there’s a problem with the inverter/converter unit. In the unlikely event you have a separate converter the same test applies however you will only need to replace the converter.

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