Forum Discussion

Octaneforce's avatar
Octaneforce
Explorer
Nov 11, 2019

Strange house battery issue

My rig is a 1993 fleetwood 30ft chevy class a.

So i think i need a little education before i can properly explain whats happening, but I’ll try. When plugged in, all my 12v powered items are struggling as if the house batteries are dead. The furnace blows slowly and doesnt light, the hot water heater doesnt light, the lights in the cieling are dim, etc.

So i guess my question is, why arent the batteries charging? How are the house batteries “tendered”?

If i shut off the house batteries while its plugged in, everything gets even more weak. Its like im not getting enough voltage to my 12v appliances. The 115v outlets are fine. Im not sure where to start.


  • Heres my current converter. It was under the oven/kitchen area as mentioned (thanks!). I dont think its original.
  • Octaneforce wrote:

    So i guess my question is, why arent the batteries charging? How are the house batteries “tendered”?


    When you are not plugged in, the batteries are NOT "tendered"; not charging at all. Batteries left completely discharged will not last long.

    One of two things: Batteries have gone bad....OR....the charger has failed. You really should get a digital multi-meter. Around $10 at Harbor Freight.
  • Check the batteries first. Bad batteries with dead cells will quite often not take any charge. Dead cells will bubble and boil but that is it. One bad battery in series will keep the others from working acting as a wall between it and the others.It or they may have some charge but not enough to function.
    If these are flooded batteries, how long since you checked the electrolite level. You may have essentially bone dry batteries.
  • You would have a 63XX Magtek converter and it's shot by now. I suggest you get a new PDI9260 converter from Bestconverter.com. They will also have videos on how to change it out. The new one will have multiple stages and work better than the old one ever did!
    Unless your battery(s) are fairly new, plan on replacing them too as the discharged condition will have taken its toll on them.
  • Gjac's avatar
    Gjac
    Explorer III
    Start with the basics first what does the 120v outlet read where you plug in? Plug in MH what is the output of your converter? Should be 13 plus volts or better. Next check the voltage across the pos and neg terminals of your battery, what does it read? Unplug MH and check voltage again the following day what does it read? Post these readings and you will find your problem.
  • Bad batteries can cause some strange symptoms. If I were you, I would check them first.
    Like said above, a voltmeter is needed to do a proper diagnosis. Maybe you can get an electrical person to help you.
  • Make and model of converter?

    Use a volt meter to check voltage under load.

    How old are the batteries?

    How long to you charge them before a trip?

    Have you ever equalized the battery bank?
  • the power converter/charger does two things simultaneously while plugged into shore power or when the genny is running:

    - it charges the house battery (or batteries). it usually does not charge the chassis (starting battery)
    - it converts 120vac to 12vdc and powers your 12vdc appliances. lights, rv fridge, etc.

    it sounds like one of two things are wrong.

    - there should be two circuit breakers on the converter. one or both may have tripped. if so your batteries will not be charged. that could explain what you’re experiencing.

    - the converter is kaput and should be replaced.

    - disconnect from shore power and don’t run the genny. are your lights still dim? if yes then using a battery hydrometer check the state of charge in each cell of each battery. i’ll bet the charge is low. if so disconnect the cables from each battery and using a standard automotive battery charger charge them overnight. reconnect the batteries and while still disconnected from shore power and the genny off see if your lights and other 12v stuff is normal.

    - if you’re handy and can use a multimeter check the voltage coming IN to the converter (should be ~120vav). then check the output voltage (should be 12vdc)

    betcha your converter is dead.

    good luck.
  • Sounds like your converter is shot. Can not help you on where it located, but it might be close to your power cord when it comes in to the RV.

    Looking Online it shows some were next to the heater inlet behind a door.