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Another 12v battery question ...

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by yankeemikehotel, May 14, 2015.

  1. yankeemikehotel

    yankeemikehotel New Member

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    Good morning,

    After trying to research though the forum I still have a quick question regarding the 12v. I had the HV pack refurbished two months ago and was running strong until two days ago. I noticed the battery was dapleated to one purple bar and after driving a few miles shot up to full green, then back to middle blue. Drove to store, and on way home the triangle and two orange warning lights all came on. As did the rear battery fan. I was able to make it home.
    I am contacting the ones that replaced battery but was wondering if a low 12v could cause such issues? My wife had left a dome light on overnight the day prior to this happening.
    Thank you for your time.
    2006 prius
     
    #1 yankeemikehotel, May 14, 2015
  2. JC91006

    JC91006 Senior Member

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    No not 12v problem
     
    #2 JC91006, May 14, 2015
  3. Mendel Leisk

    Mendel Leisk Senior Member

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    While they may not be related, you probably do have a low 12 volt too. Check it's voltage with a digital volt meter.

    I we could run a pool I'd put dibs on 11.9. :)
     
    #3 Mendel Leisk, May 14, 2015
  4. yankeemikehotel

    yankeemikehotel New Member

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    It is at 11.9 /12.0 while running. I am going to replace this week but wanted to make sure before paying labor on HV warranty
     
    #4 yankeemikehotel, May 14, 2015
  5. JC91006

    JC91006 Senior Member

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    While running in Ready mode, it should be closer to 13.8 volts. At 11.9, you would have a problem
     
    #5 JC91006, May 14, 2015
  6. yankeemikehotel

    yankeemikehotel New Member

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    But it would it be causing the issues that I'm having?
     
    #6 yankeemikehotel, May 14, 2015
  7. JC91006

    JC91006 Senior Member

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    You have to confirm the reading while the car is ready, if it's really 11.9, you have another problem to worry about
     
    #7 JC91006, May 14, 2015
  8. yankeemikehotel

    yankeemikehotel New Member

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    Sorry, still new here. What other problems besides replacing the 12v? I'm having the one that replaced the battery look at it today, but just trying to learn what I can and see what I can check. Running codes today as well. Needed a new code reader.
     
    #8 yankeemikehotel, May 14, 2015
  9. Mendel Leisk

    Mendel Leisk Senior Member

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    Deal with the 12 volt first, no harm in seeing what that does. If you replace it, don't use a memory saver, just disconnect, maybe that'll reset the lights.

    I left the driver's door ajar for about 18 hours, about a week back. It was pretty much the first time, on a 4+ year old battery. When I checked with DVM it was (you guessed it) 11.9. I hooked up a CTEK 3300, and it charged for about 11 hours before I got green (done) light.

    It seems to be back to status quo now. Obviously these hits take a toll, but it's still functional.
     
    #9 Mendel Leisk, May 14, 2015
  10. JC91006

    JC91006 Senior Member

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    I was wondering how you got 11.9........I said what a crazy guess
     
    #10 JC91006, May 14, 2015
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  11. yankeemikehotel

    yankeemikehotel New Member

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    Could the 12v really throw HV battery issues?
     
    #11 yankeemikehotel, May 14, 2015
  12. JC91006

    JC91006 Senior Member

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    not really, it should be a totally different issue.

    You should really get the DTC codes read.
     
    #12 JC91006, May 14, 2015
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  13. dolj

    dolj Senior Member

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    I agree with JC on both points.

    However, there could be a correlation.

    If your 11.9 V reading really was taken while your car was READY, then that would indicate your DC/DC converter (within the inverter) was not powering the 12 V bus to charge your battery. The DC/DC converter, in turn, might be broken, or, it may not be functioning correctly because the HV battery has failed. Even if that was the case, the ICE should turn the MG1 to provide power, so less likely a malfunction and more likely it is broken.

    My money, though, is on the HV battery has failed.
     
    #13 dolj, May 14, 2015
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