What can cause the Hybrid Battery Failure ?

Discussion in 'Gen 2 Prius Technical Discussion' started by GeneralGump, Dec 16, 2016.

  1. GeneralGump

    GeneralGump Junior Member

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    So, about a month ago I had a bad cell in my hybrid battery. It was causing a ground short to the case of about -120V and the computer detected this fault and wouldn't allow me to start the car. I replaced the cell but didn't recondition the pack. (mistake) Ultimately, I ended up having to swap out the entire pack to a local guy who reconditions packs and put in this new pack.

    Things were great for about 3 weeks. Then yesterday I get another P0A80 code that I have a voltage mismatch. With it being a completely different pack that is conditioned and volt matched (supposedly), and a new hybrid computer that came with his pack, I am skeptical now to have another failure so soon after I swapped packs.

    What else downstream of the battery could cause my cells to be getting out of sync on their voltages? I already replaced the 12v battery in my car about 4-5 months ago. it is reading 12.67V with my multimeter when the car is off.

    Is there anything else that could be causing my cells to go bad? I am going to get another pack and swap it in from the guy, but maybe I am not hitting the root cause of the problem by just swapping packs.

    Thanks for any feedback.
     
  2. jadziasman

    jadziasman Prius owner emeritus

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    I suspect that the rebuilder of your battery pack is the problem. It takes skill (and a little luck) to refurbish these batteries. If you plan on keeping your Prius for a long time you should consider buying a brand new pack from a stealership. Three year warranty on it and it will easily outlast rebuilts by three times or more.
     
  3. The Electric Me

    The Electric Me Go Speed Go!

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    I'm seriously just curious.
    Why would you need a new hybrid computer?

    If the failure was singularly with the HV battery? What evidence or need to replace the hybrid computer?
     
  4. bisco

    bisco cookie crumbler

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    with reconditioned packs, it's always the pack there's no way to guarantee a long lasting product unless you use all new cells.
    if there's something else wrong with your car, it wouldn't run properly, get bad mpg's and/or throw a dtc. have you checked with tech stream?
     
  5. ericbecky

    ericbecky Hybrid Battery Hero

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    GeneralGump,
    Can you please let us know the name of your rebuilder?

    Batteries fail for various reasons.
    - Mismatched capacity
    - Mismatched Internal Resistance
    - Mismatched self-discharge rates
    - Shorted cell
    - Electrolyte Leakage
    - Overheating (fan failure)
    - Broken voltage sensing wire
    - Broken temperature sensing wire
    - Corroded harness connectors
    - Corroded bussbars
    - Improperly tightened nuts/bolts

    It's pretty amazing the batteries work as long as they do considering all the potential failure variables.
    It is very hard to make a healthy pack that has long term reliability from used modules.
    Too often rebuilders are learning how to do the job at your expense.

    It's been interesting to watch this industry grow since its infancy over a decade ago.
     
    m.wynn, Raytheeagle and bisco like this.
  6. GeneralGump

    GeneralGump Junior Member

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    I don't think you "need" a new computer, but as you probably know, it is much easier to just swap the entire pack in the casing. So, the computer and connection for the hybrid system all come as one big piece. Just 5-6 bolts total that latch it down to the car. So we just swapped the entire pack. From my perspective, it was a good trade. Giving up my computer that was 8 years old with 225k miles for something that is more than likely newer.
     
  7. GeneralGump

    GeneralGump Junior Member

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    Well, new pack is in now after a second swap out in the last month. Hopefully this one works. I am not sure what you mean about the tech stream.
     
  8. GeneralGump

    GeneralGump Junior Member

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    Thanks for the info. He is a local guy in Phoenix. I'm not sure if his name is that important to this conversation. He does have a very thorough system of matching capacities, voltages, etc. He has a bunch of Hi-Tec battery chargers and connects everything up on a custom wiring harness. He seemed to know what he was doing in every conversation I had with him. I am very happy that he was willing to swap out the pack that gave me the new error code for another one. Hopefully, this will do the trick and I can get another couple years out of this pack.
     
  9. bisco

    bisco cookie crumbler

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    tech stream is the toyota software you need to read trouble codes, to find if something is going on besides the hybrid battery. all the best!(y)
     
  10. ericbecky

    ericbecky Hybrid Battery Hero

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    <rant on>
    The name is important because there are plenty of no-name or criagslisters who are known to provide crap packs to hybrid owners.
    Can save us a lot of trouble armchair guessing at your problem if we already know that the seller is a known bad apple. (I'm looking at you Elite Auto - Elite Auto - Beware. Craigslist hybrid battery ads should make you leery | PriusChat)

    Prius owners come here for free advice, it would be helpful if they also were willing to reciprocate with information they possess as well. It shouldn't be a one-way street here. Makes the forums, and the community a better place. We should all be willing to look out for our fellow owners. <rant off>

    That said, there are guys like Phoenix Hybrid Batteries, that you can trust.
    Listens to customers. Stands behind his products.
    Hopefully that is the super secret, mystery person your are dealing with.
     
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