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Will dead cell HV battery drain the 12V battery?

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by MikeSF, Oct 23, 2021.

  1. MikeSF

    MikeSF Member

    Joined:
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    Location:
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    Vehicle:
    2006 Prius
    Haven't been driving the car much since the HV battery decided to die on me before 150k miles... but it's a 2006 so well after 10 years. Haven't been driving much at all for a few weeks, just moving the car across the street to keep ahead of street sweeper/parking tickets. And well wife tried to move car and nothing, no start, no electronic locks, zero.

    So long story short put a voltmeter across the terminals and ready 2.45 volts, nope didnt miss a 1 at the beginning of that number. And was quite shocked that it discharged that deeply.

    So could the HV battery be the culprit for that directly? Or the quick move across the street over the past few weeks without letting it fully idle prematurely wrecked it?
     
  2. bisco

    bisco cookie crumbler

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    nope, just sitting is what killed the 12 volt
     
  3. Brucetafer

    Brucetafer Member

    Joined:
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    Location:
    Orlando Florida
    Vehicle:
    2013 Prius
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    Two
    since I've been a prius owner since the day they were brought here in 2000, and after many and many and many of them, including the 4 in my driveway currently, I've seen things that would make a British (pre ford) jaguar proud.. im dealing with a Isolation fault in my 2009, and my brand new yellow top has a solid draw that goes away when I remove the battery from the body... so unless you know how to take those pesky probes and poke and prod all over the place, I wouldn't assume until you verify.. the hybrid battery ECU does corrode naturally and might ground out like mine did and made an awesome disco smoke show minus the fringe, bellbottoms and sequins..
     
  4. sam spade 2

    sam spade 2 Senior Member

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    NO and NO.
    Likely that either the battery has just failed.
    OR a light was left ON or a relay stuck and drained it down to nothing.