Prius HV Battery cell failure rate

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by gatorback, Dec 15, 2025 at 4:12 PM.

  1. gatorback

    gatorback Junior Member

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    My 2010 has 92K miles on it, so I am not sure if the age / mileage helps to forecast the HV battery outlook.

    I am forward to examining the HV battery through the Panlong Bluetooth OBD 2 device, which arrived via Amazon yesterday. It seems that the Dr. Prius app is the weapon of choice for this exercise, though I am open to other suggestions. Q1: I would like to understand how others are using this data to forecast (be prepared) for HV battery cell failure.


    Q2: When the first cell fails, should I expect the remaining cells to quickly (within weeks) to quickly follow suit and fail? Or does replacing the cell buy a significant amount of service before the next cell fails?
     
    #1 gatorback, Dec 15, 2025 at 4:12 PM
  2. PriusCamper

    PriusCamper Senior Member

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    I'm charging and balancing a person's pack in their original 2007 Prius and its still going strong... Sadly, mechanics and Toyota stealerships recommend replacing the whole pack on almost any battery pack related to any error for the pack, even when the problem isn't a failing cell and cheap to fix. You can learn more about charging and balancing and reconditioning to maximize the lifespan of your pack here: FAQ - Hybrid Automotive
     
    #2 PriusCamper, Dec 15, 2025 at 7:37 PM
    Last edited: Dec 16, 2025 at 2:49 AM
  3. bisco

    bisco cookie crumbler

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    generally, the center modules go first due to heat. replacing them doesn't lead to more failure, but without proper balancing/reconditioning, you're playing whack a mole.
    either way, it's an old battery that will be prone to failure, but there's no way to determine when.
     
    #3 bisco, Dec 15, 2025 at 8:37 PM
    Brian1954 likes this.
  4. Brian1954

    Brian1954 Senior Member

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    #4 Brian1954, Dec 15, 2025 at 9:25 PM
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