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ryanPSD's avatar
ryanPSD
Explorer
Jul 21, 2016

New 6 volt batteries, problem?

Hey everyone,

Hoping for some input on the new battery situation. We have a 2015 class C, about one year old next month. I’ve replaced the converter in my WFCO 8955 with a Progressive Dynamics 9270 already.

In the last week I purchased two new 6 volt US Battery 2200’s to replace the factory 12v’s house batteries that came with it. Date stamp on the new batteries was Feb (IIRC) 2016. When I installed them, voltage on each was around 6.2, and 12.4 when wired up. I figured no problem, and left the RV connected to shore power for about 3 days before our trip this weekend.

Upon unplugging and driving to our campsite today (less than 20 miles), my volt meter shows still 12.4 on the batteries. Any idea what gives? Shouldn’t I be seeing 12.7+ on a full charge still with two 6v batts in series?

I did notice the other day that the electrolyte level on the new batteries was not close to the bottom of the fill neck, but about halfway down to the plates. I estimate 1/2” above the plates, and 1/2” below the fill neck. I did not get a chance to top them off, but assumed they would be fine for the moment. I assume this should be the typical 1/8” or so just below the fill neck on these as well? The RV was level while charging, and is level at the campsite.

I did not check voltage after unplugging from shore power, before leaving. I only did prior to unplugging and the PD9270 was in storage mode at the time, it was around 13.2v if I recall, but I know it charged these batteries in all stages. The converter had no issues charging the previous 12v batteries.

Had to run back to work for the rest of the day but will be back this evening to see how they are doing, with the family using them. I don’t have a hydrometer but I think that may be next on my list.

Thank you for any input!

25 Replies

  • sounds like
    something is wired wrong
    dropped / lost a wire during the battery change out
    you have 'house loads' running and NO charging from the battery isolator alternator circuit
    blow fuse in charge circuit ?
    dropped missing wire ?

    what was on inside the RV, put fridge on LP not electric not auto
    batteries should not have dropped that much, just running CO detector and fridge LP controls, unless you have a residential fridge powered by inverter ?
  • Posted before I saw your edit, I believe the PD charge wizard does an equalization every 21 hours at 14.4v for 15 minutes. RV was plugged in for near 3 days before leaving. I feel I may wind up trying an exchange after we get back from this weekend.
  • Hmm.. it sounds like the charger is working properly. Is there some draw on these batteries you're not aware of? Can you unhook them when (supposedly) fully charged, let them sit for a half hour and check voltage again?
  • 2oldman wrote:
    Assuming your VM is accurate, you did buy under-charged batteries, but that shouldn't be a big deal. Electrolyte sounds fine - as long as it's above the plates.

    I'm a bit confused as to whether you've checked the voltage at the batteries when plugged in and charging. Next I'd be considering doing an equalization charge, or exchanging them, assuming your voltmeter is correct.


    Thank you for the quick reply. Sorry, typing on my phone and it may not have come out right. I checked voltage when I first plugged in to charge, and saw around 14.4v, indicating the PD's bulk charge. After a couple days, today, before unplugging, voltage showed around 13.1v-13.2v. Did not check after unplugging, before driving. After driving to campsite, voltage showed 12.35v-12.4v.
  • Assuming your VM is accurate, you did buy under-charged batteries, but that shouldn't be a big deal. Electrolyte sounds fine - as long as it's above the plates.

    I'm a bit confused as to whether you've checked the voltage at the batteries when plugged in and charging. Next I'd be considering doing an equalization charge, or exchanging them, assuming your voltmeter is correct.

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