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How does my battery health look? Seem to be having issues with bank #11. Battery is a few years old.

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by Jagdepanzer, May 10, 2023.

  1. Jagdepanzer

    Jagdepanzer New Member

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    Bought a Prius with 300k miles recently. Battery has been replaced a few years ago, was looking at the Dr. Prius app and seem to have an issue with bank #11. It's very high resistance and has very high voltage difference under heavy load.

    Heavy load:

    Screenshot_20230510-211949_Photos.jpg

    No load other than car on:

    Screenshot_20230510-203552_Dr Prius.jpg

    Battery test results:
    Screenshot_20230502-144806_Dr Prius.jpg

    My battery scored 83% health with 20 seconds of discrepancy due to me adjusting voltage use.

    I'm fairly technical and very mechanically inclined, but I don't know anything about hybrids/batteries. How big of an issue is this? How hard would it be to fix, if needed? I would rather not buy a new/refurbished battery, I'd rather fix it myself if need be.

    Sounds like if I needed to replace it I'd have to find a bank with very similar voltage? How does the charge/discharge part work once you get everything back together?
     

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    #1 Jagdepanzer, May 10, 2023
  2. Jagdepanzer

    Jagdepanzer New Member

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    Better images
     

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    #2 Jagdepanzer, May 10, 2023
  3. JC91006

    JC91006 Senior Member

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    Try to force charge it, with the car in Drive, hold the brake down and floor the gas pedal. Look at your battery state of charge meter and watch the battery charge up to full. Drain the battery (sit in the car with AC blasting), repeat the force charging a couple times.
     
    #3 JC91006, May 11, 2023
  4. bisco

    bisco cookie crumbler

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    it's time consuming to fix, but not difficult. plenty of good threads here, the more time you spend, the more reliable it will be
     
    #4 bisco, May 11, 2023
  5. Jagdepanzer

    Jagdepanzer New Member

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    One issues that I didn't think of until now, my car has a GreenTec auto battery installed with dynamite shaped cells. Warranty is out on it, and they don't sell singular blades. Does anyone know where I can find these blades so I can replace the one going bad on my car? I was told by a rep "Our battery supplier supplies multiple brands, I can't tell you who our supplier is but if you find them you can buy singular blades".

    I'll be ripping into the battery in the next few days probably, maybe I can find a part number or something on one of the blades.
     
    #5 Jagdepanzer, May 12, 2023
  6. edthefox5

    edthefox5 Senior Member

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    Common for that battery position to fail first as its an interior battery in the battery block and gets the hottest. Make sure your hybrid battery fan inlet is not clogged and the fan itself is clean and working good and all the battery vent piping is in place.

    And you don't need to floor it to force charge it. Just press the gas pedal gently enough to see the charge cycle begin on the mfd.

    Did that for months before replacing my battery. But mine did not have a failing module just a tired under used battery in general.
    You have a failing module and the rest of the battery is very unbalanced.

    My guess is the car sat a long time.
     
    #6 edthefox5, May 12, 2023
    Last edited: May 12, 2023
  7. Jagdepanzer

    Jagdepanzer New Member

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    What's the best course of action?
     
    #7 Jagdepanzer, May 12, 2023
  8. edthefox5

    edthefox5 Senior Member

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    A bad hybrid battery and its repair/replacement is the #1 post on this site. Hundreds of posts about it. Lots and lots of youtube video's also.

    It all depends on your engineering skills if your going to diy or your wallet size if wanting to just replace. Since you have 300K miles I doubt you want to put any money into anyway.

    Using the search forums link here's some posts about a bad hybrid battery. Start reading:

    https://priuschat.com/search/425893135/?q=bad+hybrid+battery&t=post&o=relevance
     
    #8 edthefox5, May 12, 2023
  9. Jagdepanzer

    Jagdepanzer New Member

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    Thanks
     
    #9 Jagdepanzer, Apr 19, 2024
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