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midnightsadie's avatar
midnightsadie
Explorer II
May 31, 2013

12 volt help

both batteries read 12,8 and 12.9 two yr,s old not much use.out of the rv, problem.plug in dig meter in coach reads ,13,44 when plugged into shore power .turn shore power off and turn one light on meter reads 10.56 where,d the volts go?? my converter is a parallax 7300 series the rv is a 2007. 30k om rv.
Class C
  • Queens_Carriage's avatar
    Queens_Carriage
    Explorer
    May 31, 2013
    Fully charge them up one at a time. After they are charged disconnect them, let stand for 12 Hrs. Them check voltage. Should be 12.6-12.8. Let sit for another 12 Hrs. check again. Then check after another 24 Hrs. That will tell you if you have a bad cell.
  • rvten's avatar
    rvten
    Explorer
    May 31, 2013
    Many of us with a Parallax converter have replaced it.
    It can over charge your batts if left on in storage.

    Check your batts for water. Check batt connections.
  • Joe_Hamm's avatar
    Joe_Hamm
    Explorer
    May 31, 2013
    You are receiving some good advice. Charge then up then test. If they will not hold charge then load test them at any auto parts. Here is a good link if you want to test yourself.
    http://blog.rv.net/2009/11/testing-your-battery-state-of-charge/
  • tenbear's avatar
    tenbear
    Explorer
    May 31, 2013
    The Parallax converter is a slow charger. If they haven't been on charge, charge them up for a couple of days and do your check again.
  • time2roll's avatar
    time2roll
    Nomad
    May 31, 2013
    Were they kept charged in storage?

    Otherwise it looks like a classic shorted cell and time for a new battery.
    How is the water level?
  • vermilye's avatar
    vermilye
    Explorer
    May 31, 2013
    Could be lots of things - if it isn't too difficult to pull the batteries, I'd start by taking them to a Auto Parts store for a load test.

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