Forum Discussion

fighterpilota's avatar
Dec 09, 2013

House battery being overcharged????

1994 Calista Cove MH. Book says charging system will sense fully charged and not over charge the house battery. After being hooked to shore power the volt reading at the battery terminals is 14.2 volts which seems like too much. ????

17 Replies

  • I did not read through the other replies, but 14.2 volts seems normal to me. With most on-board RV chargers these days, if you are over-charging, the batteries will boil over. And if they boil over, it may be because one of the two batteries is either dead or dying. Such a battery will never get fully charged which causes the charger to over-charge both batteries.
  • My 2004 TT has the Parallax 7355 converter, it will definitely cook the battery if left on shore power too long (more than 2 weeks). The older converters don't have the smarts to switch to a maintenance charge once the battery is completely charged.

    An easy way to check for overcharging is to remove the caps on the battery and check for lots of bubbles after the voltage across the battery reaches 14 volts.

    You might want to invest in a battery disconnect switch if you're connected to shore power for long periods.
  • fighterpilota wrote:
    After being hooked to shore power the volt reading at the battery terminals is 14.2 volts which seems like too much. ????


    No.

    The only way you can truly tell if a battery is fully charged is with a hydrometer.

    What does the voltmeter read three hours after the charger has been turned off and there has been no load is on the battery. That's the only valid way to get a reading with a voltmeter on a battery charge.
  • What is the make and model of your converter? If it is a Magnetek or Parallax it is not a smart charger and the voltage should be 3.8v at the converter, probably lower at the battery.
  • Is that the voltage reading while on shore power? What is the voltage on the battery a few hours after not on shore power?
  • Been hooked to shore power for days and the battery new within the last two years. But they have been known to fail. I have a load tester, will try that. Voltage been 14.0 when I checked yesterday and still 14.0 this afternoon. Did they have smart chargers back in 1994??
  • How long has it been hooked to shore power?
    After the converter feels the battery is sufficiently charged, the voltage will drop to something like 13.6VDC if the converter and battery are in good shape.

    Scott