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Code P0A80 -- seeking info and feedback

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by JoJo_NC, Jan 16, 2015.

  1. JoJo_NC

    JoJo_NC Junior Member

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    Hi all,
    2004 Prius with 160,000 miles. Got the red triangle of death, along with check engine, orange (!), and VSC lights, and codes P0A80 and P3020. From what I've read on PC these warning lights are pretty common with the P0A80 code and confirm a failure of the hybrid battery (not sure about the P3020 but maybe that's identifying the problem cell?).

    I'm not very handy (replacing the 12v battery last year was pushing the limits of my abilities) and don't have a ton of spare time so I'll probably pay someone to do the work. I'm probably going to have the faulty cells replaced vs installing a remanufactured battery, for cost reasons, though not totally decided yet.

    What I'm hoping for most in terms of feedback from PC is the things I should be absolutely certain of when asking a mechanic what they plan to do. From what I've read, balancing is crucial, and every mechanic I've called has said they do balance all cells. so a couple other questions I have:
    • Is all balancing created equal? I spoke to one mechanic (Curry's auto in Arlington VA) who claims his process is better b/c they have some proprietary method whereby they do a "power and energy test" and then drain all the cells before re-charging all of them. Is this process really any different than what any person is going to do in terms of re-charging weak cells and balancing? (notably they offer a 3 yr warranty which is way beyond the other guys that do cell replacement).
    • Do both cells within a module need to be replaced? I spoke to one guy who said he only replaces them in pairs, he won't install a new cell in a module while leaving the other old cell there.
    • Do cells need to be within .5 or .3 variance of one another? I seem to have read both on different threads here.
    • Can corrosion alone cause the P0A80 (and all the dashboard lights I'm getting)? Is it technically possible but very unlikely?
    • What else do I need to be thinking about / asking? Is there something I've missed entirely?
    I'm located in the MD suburbs of DC . Found a thread here with mechanics in the DC area and called 7 places so far, with price quotes of $575 (random guy on Craigslist) to $2500 (Mac's in VA). Obviously I'm tempted to go cheap but want to be sure he'll do the job right, if not I'll pay the extra.

    FYI in terms of the conditions that led to the hybrid failure: I hadn't started the car in maybe 5 days and it was during a cold snap so I understand that may not have helped. Also this has been a TX, FL and NC car til last year so lots of hot weather which I understand can also tax the hybrid battery.

    Thanks in advance for any and all feedback.
     
    #1 JoJo_NC, Jan 16, 2015
    Last edited: Feb 3, 2015
  2. Easy Rider 2

    Easy Rider 2 Senior Member

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    At 10 years and 160K miles, my opinion is:
    Replacing individual cells is probably NOT cost effective......as I think more of the old cells are likely to fail relatively soon.
    That is if you plan to keep the car at least a year.

    If you are trying to do just the minimum to get it ready to sell or trade........then that's a different story.
     
  3. bisco

    bisco cookie crumbler

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    i'm amazed at how many places you have found that do this kind of work. that's quite a list. my advice would be to pm member 'ericbecky', if he doesn't chime in here. he's the resident expert and will be happy to point you in the right direction. all the best.(y)
     
  4. GregP507

    GregP507 Senior Member

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    Bad cells are one thing; they need to be replaced, and the rest of the battery may have many happy miles on it. However, when a battery starts to wear out, the first cells to go are followed soon-after by their siblings, and it's a fool's errand to keep replacing them.

    The difference is shown us by a good and honest mechanic, not one who just wants to skin us in any way possible.
     
  5. nh7o

    nh7o Off grid since 1980

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    That has not been a concern with the various battery rebuilds that have been posted here. All the cells in the battery are in series, and all play exactly the same role, and have the same current flow. The use of the term "module" is conceptual only, and is just a means of measurement for the battery management system, so that it can provide a fine enough detail. Toyota could just as well have put 4 cells in a module, with less granular data, or it could have measured all the cells, with greater cost and complexity. Once a module has been flagged as being out of spec, it could be either one of the cells that is at fault, or even both. Generally people have reported multiple cells that are weak, randomly spread through the whole bank.
    Less is better. It depends on how long you want the repair to last. Some have needed to replace additional cells within months. The resulting "whack-a-mole" syndrome is what has some people just getting a new bank, if they need the car to be reliable.
    So far that has not been the root cause of failure, more an effect. The corrosion occurs as battery electrolyte is vented from overheating cells. Those cells would be suspect for replacement.
     
  6. ericbecky

    ericbecky Hybrid Battery Hero

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    I agree with the question of how long you want it to last, plus will the company still be around to support you if there is an issue.
    To a large degree, you get what you pay for.
    Generally I would agree with replacing cells in pairs. But I know not everyone cares to do it this way.
    Corrosion can cause quite a few issues.

    Anyone can call their method "proprietary". I'd take that with a grain of salt.
    If I remember right, p3020 is block#10.

    If you are not doing the work yourself, I'd want to pay someone one time to get a replacement pack.
    Either get a new one, or get a quality rebuilt one. Rather than palying the whack-a-mole game with your existing battery pack.

    If you were really handy and enjoyed the process of taking your car and hybrid battery pack apart, then maybe it might be worth it to do just one module. But when you are paying by the job or by the hour, I don't think it'll be worth it in the long run.

    Feel free to call. I'd be happy to expand on this a little, including the whole "proprietary method" thing.
     
    bisco likes this.
  7. wa-chiss

    wa-chiss Member

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    When a Prius comes into my shop with that code, before I condemn the traction battery, I'll inspect the cooling fan for excessive build up on the fins that could cause loss of cooling. There's actually a bulletin for this concern. Although the true tell-tale sign is the ballance of the cells, it's still posible to have just a clogged fan that can reveil a weaker cell with excess heat. I wish I still had a picture of the clogged fan I replaced a couple of weeks ago. It was BAD. Replaced fan and cleared dtc's. Drove it a week to home/work and kept an eye on the ballance. All was good after that.
     
  8. GregP507

    GregP507 Senior Member

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    Side-thread: If your Prius goes into the water, do you electrocute before you drown?
     
  9. JC91006

    JC91006 Senior Member

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    Are you saying dealers are not replacing batteries (warranty) with that code now? Just cleaning the fan and have the customer go on their way?
     
  10. Yakoma

    Yakoma Active Member

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    I hope there's a big-nice person fuse for this.
     
  11. Yakoma

    Yakoma Active Member

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    Before you take it in to replace, this would be a good half-measure to try. All it takes is a socket set, a dry garage and some patience. I removed and cleaned mine in 30 minutes using a YouTube video as guide. If this is all it takes, it's basically free.
     
  12. GregP507

    GregP507 Senior Member

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    I always use a compressed-air blow-gun to clean air-filters. I don't believe the crap about damaging the paper element by doing so. I'm not the numb-skull they seem to take us for.
     
  13. wa-chiss

    wa-chiss Member

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    jc91006: not at all. It's at least a point of interest. I've had 3 prii in the last month with P0A80 and only one (the one I mentioned earlier) had a clogged fan. The other two needed batteries. Both were low on 2 or three blocks by like 2v. The one with the dirty fan got it cleaned and the P0A80 never returned for the remainder of the time I had it and maintained a steady ballance within specs. of .3v.
     
  14. Easy Rider 2

    Easy Rider 2 Senior Member

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    I think that theory remains unproven.
    There is considerable evidence to the contrary. :)

    For instance, which side do you blow FROM ??
     
  15. GregP507

    GregP507 Senior Member

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    Always good to hear from you. Are the vitamins helping?
     
  16. Easy Rider 2

    Easy Rider 2 Senior Member

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    Answer the question please.
    When cleaning a filter with compressed air, which side of the filter do you blow the air onto ??
     
  17. GregP507

    GregP507 Senior Member

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    If you don't know, you don't deserve having me telling you.
     
  18. Easy Rider 2

    Easy Rider 2 Senior Member

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    I know what the right thing to do is.
    I am asking what YOU do.
    It is not a hard question.
     
  19. GregP507

    GregP507 Senior Member

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    Not a hard question; even a numb-skull should know the answer.

    I was doing this for my dad since I was about six, and even then, I knew how to do it without poking a hole in it. We used some of those filters for 20 years.
     
  20. Easy Rider 2

    Easy Rider 2 Senior Member

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    Nobody but YOU knows how YOU do it.

    But in the interest of forum harmony, I will drop the question.