All 14 battery pairs show great voltage, But CEL replace hybrid Batt

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by poway, Aug 7, 2026 at 12:42 PM.

  1. poway

    poway Junior Member

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    Hello all,
    2013 Prius V, 230,000 miles. Replaced 3 battery packs 6 months ago. All 14 pairs show great voltage. Car worked great for 6 months. Left car unused in FL 90 degree weather. Now getting CEL P0A80 (check engine light) to replace hybrid battery. Along with C1259HV control system regenerative malfunction. Replaced the two expensive brake components in engine compartment in Jan. I believe this code is related to the Hybrid batt. After I clear the CEL it takes approximately 50 miles for it to reappear. It's after the second start, of the day. Any ideas on how to proceed greatly appreciated! IMG_1046.jpeg IMG_1048.jpeg
     
    #1 poway, Aug 7, 2026 at 12:42 PM
  2. bisco

    bisco cookie crumbler

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    are you testing the battery under load?

    when you say battery packs, do you mean modules?
     
    #2 bisco, Aug 7, 2026 at 1:09 PM
  3. ChapmanF

    ChapmanF Senior Member

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    #3 ChapmanF, Aug 7, 2026 at 1:37 PM
  4. Brian1954

    Brian1954 Senior Member

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    To help troubleshoot, you need a good scanner that can read the freeze frame data for the P0A80 code. The freeze frame data will show the voltages of the 14 battery blocks when the P0A80 was triggered. Looking at the battery block voltages should tell you which battery block is the problem.
     
    #4 Brian1954, Aug 7, 2026 at 2:00 PM
  5. PriusCamper

    PriusCamper Senior Member

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    When an older Prius sits for a good long while unused the battery cells self-discharge at different rates. So when taking a Prius out of storage doing a full charge and balance on the hybrid battery prevents this problem.
     
    #5 PriusCamper, Aug 7, 2026 at 3:33 PM
  6. rjparker

    rjparker Tu Humilde Sirviente

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    It is not uncommon for "reconditioned" batteries to quickly fail again even when professionally refurbished (video below) and operated at least weekly.

    You either go through the process again or you bite the bullet and buy a new set of oem modules which will work trouble free for another 10-15 years.

    The Hybrid Guy NiMh Battery Rebuild
     
    #6 rjparker, Aug 7, 2026 at 3:35 PM
    Brian1954 likes this.
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