P0A80 options

Discussion in 'Gen 3 Prius Technical Discussion' started by Matt98svt, Jul 21, 2026.

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  1. Hybrid Battery Exchange

    Hybrid Battery Exchange Member

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    This is excellent data, along with your individual voltage numbers point at module 4 and 5 as being the problem. The rest of the pack seem to be fairly well balanced.

    In my experience once the battery modules begin deviating in voltage a high voltage charger like the prolong will only temporarily mask the problem. Once battery module begin to deviate in voltage they need to be replaced, even full reconditioning doesn't fix the issue (have tons of data showing this). The underlying problem is lack of efficiency from those modules, after a rest period or several charge and discharge cycles they will deviate again.

    The other concern is the location of the failure in the pack being block 2 and 3, the expected failure is in middle of the pack. Failures in block 1-4 usually occur due to sensing harness and battery computer corrosion. I would take a close look at those two components for any sings of oxidation. I recommend taking off the battery computer and looking at the circuit board side of the sensing plug.
     
    #21 Hybrid Battery Exchange, Jul 30, 2026 at 4:15 PM
  2. ASRDogman

    ASRDogman Senior Member

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    Had you started using the Prolong system before the issue, you likely would have been
    able to keep the pack in decent shape. Eventually, they will all fail, like any battery.

    Time for the Sodium Upgrade!
     
    #22 ASRDogman, Jul 30, 2026 at 5:07 PM
  3. Albert Barbuto

    Albert Barbuto Active Member

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    Module #1 is on passenger side. Yes, replacing the bad modules, and then doing the Prolong process, should yield good results. :)
     
    #23 Albert Barbuto, Jul 30, 2026 at 8:00 PM
  4. Matt98svt

    Matt98svt Junior Member

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    #24 Matt98svt, Aug 1, 2026 at 6:04 PM
  5. Matt98svt

    Matt98svt Junior Member

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    Looking at the wiring the new bus bars I installed when we got the car still look good but the senor wires do look darker in color on that end of the pack. They seem intact though and I cleaned them with deoxit. They looked more blackish than the green patina style corrosion that was on the original copper bus bars. I have not removed the battery computer yet but I removed all the plugs going into it and at least the plugs look nice and clean and corrosion free. I have been driving the car locally with no error codes. Delta SOC has slowly reduced to a 32.00% (which is still extremely high i know). I dont want to stress the battery too much but did a short test under load again and the #2 and #3 blocks again dropped down below the others quickly. Looking online now for replacement modules. I see some sellers advertise their reconditioned cells will have 7.5v or higher and some say 8v or higher? Anything in particular i need to look for as far as voltage goes before ordering tonight? Thanks so much
     
    #25 Matt98svt, Aug 1, 2026 at 6:16 PM
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