Finally got the P0A80 on my 2011

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by koukilights, Feb 23, 2025.

  1. koukilights

    koukilights Junior Member

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    2011 with 315k miles and I finally got the P0A80 on my original battery pack.

    I cleared the code with my generic scanner and drove the 15 miles home and it hasn't come back on yet.

    From what I've read, this is a code indicating I have a voltage difference between a few cells in the pack. What scanner can I get to monitor individual cell voltages? Techstream? Some sort of android to bluetooth obd2 scanner software?

    How long can I drive on it like this?

    What are my options to fix this? Are there aftermarket new-style cell packs that don't cost an arm and leg?
     
  2. JC91006

    JC91006 Senior Member

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    A 14 year old battery pack is already on it's last legs and should be replaced. Instead of finding a rebuilder, you should call around to local salvage/wrecking yards and see if they have a late model hybrid with similar modules you can buy. Then swap in the newer modules. This will be the best economical and reliable solution
     
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  3. koukilights

    koukilights Junior Member

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    I've tried rebuilding/replacing modules and balancing them back in my 2nd gen prius. And it never worked. I just kept getting the P0A80 code every other week. It was like wackamole.
     
  4. bisco

    bisco cookie crumbler

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    aftermarket are similarly priced to oem, around 2k.
     
  5. JC91006

    JC91006 Senior Member

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    You need to have a little skill in determining the bad modules in the pack and replacing them. If you cannot do that properly, you can buy a complete used pack from a salvage yard and put it in your car.

    That should work if it's not old
     
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  6. koukilights

    koukilights Junior Member

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    That's brand new OEM? Or refurbished/used oem packs?
     
  7. koukilights

    koukilights Junior Member

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    How do you determine the bad cells? If I remember from my 2nd gen rebuild, it was a matter of putting a smal load on the cell like a light bulb, and measuring the voltage and seeing which ones were lower than the others.

    But I could either never get all the bad cells, or perhaps the "new" cells weren't balanced properly to the pack? I don't know what exactly went wrong.

    I'm open to replacing a few cells if that would work, but I remember trying to do that, still getting the CEL, and juts buying an entire replacement pack in the end.
     
  8. bisco

    bisco cookie crumbler

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    brand new oem. call all the dealers you are willing to drive to, they are competitive
     
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  9. MAX2

    MAX2 Active Member

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    Your answers are contradictory. You claim that you repaired the high-voltage battery, but you do not know how to identify bad cells. Then what is the point of repairing? Rearranging the faulty and working ones in different places. But the sum does not change from rearranging the terms.
     
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  10. JC91006

    JC91006 Senior Member

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    There are many factors to determine if you would get a successful rebuild. It probably would help if the battery pack that you are repairing is an original pack containing most of the original modules. For example in a pack of 28 modules, you would want at least 25 of them to be the same, replacing maybe up to 3 failed modules of similar capacity and age. This will allow you to get the best results for reliability.

    If you are rebuilding a battery pack with many different modules of different age and capacities, you will have a hard time to get a reliable pack. The computer in the car will pick up the differences in voltage under load (100a) so if the modules are not very similar, you will get a failure again.

    Internal resistance in a module, the self discharge rate, voltage variations, etc all will determine how long the battery pack will last you. So you really need a little bit of skill and experience before you can properly rebuild a battery pack
     
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  11. koukilights

    koukilights Junior Member

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    Yes, on my 2nd gen prius, I replaced cells that I thought were bad. Ones that had lower voltage without a load, and doubled checked to have lower voltage with a light bulb on it as a simulated load. It didn't work and I ended up just getting a replacement pack altogether.

    So, I have replaced/repaired a HV batt, but either I had bad luck or I don't really know how to identify bad cells. Which is why I'm asking here.

    Does that make it more clear?
     
  12. MAX2

    MAX2 Active Member

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    A cell can have different voltages depending on how charged it is.

    What is low voltage in your understanding? 8v? 7v? 6v?
     
  13. koukilights

    koukilights Junior Member

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    I don't know. That's why I'm here asking for advice. 6v is definitely low. 7v under load is perhaps ok. 8 is probably good.

    But I think the bigger thing the ECU looks for is variance between cells. So if the whole pack is tired but close together, it's probably fine. Where as a pack of 7.5v cells with a few 8v cells is probably not.
     
  14. AzusaPrius

    AzusaPrius Senior Member

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    Surprised they havent answered your real question.

    Buy a Carista and download the Dr. Prius app.
     
  15. MAX2

    MAX2 Active Member

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    Don't shake the thermometer when it shows a high temperature. It won't cure it.
    When you have problematic code, you need a systematic approach. Study this.

    https://static.nhtsa.gov/odi/tsbs/2019/MC-10169322-9999.pdf

    https://share.qclt.com/%E4%B8%B0%E7%94%B0%E6%99%AE%E7%91%9E%E6%96%AF%E5%8E%9F%E5%8E%82%E8%8B%B1%E6%96%87%E6%89%8B%E5%86%8Cpdf%E6%A0%BC%E5%BC%8F/repair%20manual/04pruisr/05/20zmw/cip0a80.pdf

    https://share.qclt.com/%E4%B8%B0%E7%94%B0%E6%99%AE%E7%91%9E%E6%96%AF%E5%8E%9F%E5%8E%82%E8%8B%B1%E6%96%87%E6%89%8B%E5%86%8Cpdf%E6%A0%BC%E5%BC%8F/repair%20manual/04pruisr/05/20zmw/cip0a7f.pdf

    https://share.qclt.com/%E4%B8%B0%E7%94%B0%E6%99%AE%E7%91%9E%E6%96%AF%E5%8E%9F%E5%8E%82%E8%8B%B1%E6%96%87%E6%89%8B%E5%86%8Cpdf%E6%A0%BC%E5%BC%8F/repair%20manual/04pruisr/05/20zmw/cip3011a.pdf

    Once you have learned the basics, you need to understand what you can use to read data from various systems, including a hybrid battery.
    This could be a special program from Techstream.
    TechStream | PriusChat
    But you also need a cable to connect the computer to the program, which you need to purchase.

    Or use an OBDII adapter and a program on your phone that will allow you to read the necessary data.
    Hybrid battery diagnostic and repair tool for Toyota and Lexus
    can-newsletter.org - Miscellaneous

    Descriptions of various applications for the phone can be read here.
    https://priuschat.com/threads/gen2-obd2-app-review.232741
     
  16. rjparker

    rjparker Tu Humilde Sirviente

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    Buy new cells, you already know the whack a mole routine. Getting reliable no concern hv battery life for the next ten years is worth it.

    Dr Prius is no magic bullet and the company will offer you new sodium replacements which are unproven. Their lithium replacements and others nimh aftermarket replacements all had very short lifespans and the lithium sometimes failed with smoke in the cabin.

    But if you want to mix and match used modules (again) watch this guy:

    Prius Hybrid Battery Reconditioning "How To Properly Repair A High Voltage Nickel Metal Hydride (NiMH) Battery Pack For Hybrid Vehicles"

    the hybrid guy
     
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  17. AzusaPrius

    AzusaPrius Senior Member

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    So there is no confusion, Dr. Prius app will help you figure out which modules are bad and can give you a battery health test along with other features.

    The maker of the app also offers aftermarket battery options at sodiumhybrid.com

    This rjperson is not an actual user of any of said products.

    The Carista OBD reader is great and offers dealer settings and options and works flawlessly with the Dr. Prius app (not to be confused with sodiumhybrid.com)