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12V Battery Monitor

Discussion in 'Gen 2 Prius Accessories & Modifications' started by ccdisce, Feb 28, 2011.

  1. ccdisce

    ccdisce Active Member

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    #1 ccdisce, Feb 28, 2011
    2 people like this.
  2. 2009Prius

    2009Prius A Wimpy DIYer

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    For gen2 Prius from the OBD port we can get the 12V battery voltage, the HV battery temperature and outside air temperature. The latter two give a rough estimate of the 12V battery temperature. The chip above adds the capability to measure 12V battery current which I don't know whether we can get from the OBD port or not.

    What I do is periodically, maybe twice a month, put the battery under some load by turning on headlights and rear defogger and look at the battery voltage. This establishes a baseline. I posted some data here:
    http://priuschat.com/forums/gen-ii-...-trip-record-fun-early-problem-detection.html
    If I start to see the voltage under load to drop significantly then I know the battery may be sick.
     
    #2 2009Prius, Mar 1, 2011
  3. ccdisce

    ccdisce Active Member

    Joined:
    Oct 10, 2010
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    Location:
    Stone Mtn GA USA
    Vehicle:
    2008 Prius
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    N/A
    What I was hoping for was a package that I would install and forget ...until it sounds a Klaxon warning of impending death of the 12V battery a couple of weeks before the actual event. A day downcount on a LCD counting down the days to battery failure is good.
     
    #3 ccdisce, Mar 1, 2011
    1 person likes this.
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