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Need help understanding Dr. Prius results

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by Dusttttt, Mar 29, 2021.

  1. Dusttttt

    Dusttttt Junior Member

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    Screenshot_20210329-122431.jpg Screenshot_20210329-123142.jpg

    Hello everyone, I'm trying to fix my prius with 175k miles on it and I don't know if I need a new battery or if I can replace the bad modules with good ones. Based on these screenshots and the battery life expectancy test by Dr. Prius app, which modules are bad? 11.56% seems pretty low to me. Is this app accurate or should I do some more testing? I also have the Torque pro app and just looking at the numbers I can't figure out what my nest step should be. Any help would be much appreciated. Thanks. Screenshot_20210329-134556.jpg
     

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  2. rjparker

    rjparker Tu Humilde Sirviente

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    Certainly the age and miles are not in your favor.

    The real question is what symptoms are you having that leads you to believe a hv battery is in your future? Fast discharges at a traffic light? Fast recharges? Codes indicating problems? Poor mpg maybe ten percent off? If no symptoms then ignore Dr Prius. If you have issues, seriously consider new cells or battery.
     
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  3. Dusttttt

    Dusttttt Junior Member

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    I have the P0A80 pending fault code. If I clear the code I can drive for about a day before the Triangle light will come one and the car will only use the mechanical engine and not the battery.
     
  4. Dusttttt

    Dusttttt Junior Member

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    Do the values of these tests indicate whether or not I can replace individual cells or are they all bad?
     
  5. jdenenberg

    jdenenberg EE Professor

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    From the bar chart, module pairs 2 and 14 appear to be at a noticeably lower SOC than the others. This is a sign of future problems that may be averted by rebalancing the battery pack to extend its useful life. The "Prolong" (Prolong Value Reconditioning Package | Hybrid Automotive) can be used to do this with the pack in your Prius.

    If you have the skills to safely remove the battery pack and remove one side of the bus bars, you could try reconditioning the two weaker modules with a hobby charger as many have described in other discussions. Reconditioning your existing modules before they fail is more likely to result in a longer term repair than replacing modules.

    JeffD
     
    #5 jdenenberg, Mar 29, 2021
    Last edited: Mar 29, 2021
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  6. tankyuong

    tankyuong Senior Member

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    Best way is a multimeter to each module
     
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  7. davecook89t

    davecook89t Senior Member

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    I agree that the Prolong system might be a good investment, if the car has no other problems and is showing signs of battery degradation. However, it is hard to make a conclusion that the battery has problems based on one screen shot that shows a voltage difference of .13V, well within the normal range of variation for a healthy battery. The Life Expectancy test would be concerning if the results could be believed, but I don't think I've ever seen anyone on this forum reporting such a low number, so I would be suspicious that something had gone wrong with the test. Furthermore, I think the general consensus of members here is that the Life Expectancy number from Dr. Prius is not sufficiently accurate to make a decision about battery replacement on the basis of that value alone.
     
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  8. jdenenberg

    jdenenberg EE Professor

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    That has to be done with care as the modules are in series and the 200+ volts can kill.

    JeffD
     
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  9. rjparker

    rjparker Tu Humilde Sirviente

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    You can change individual modules and get rid of the code for a month, three months or maybe a little more. Two years from now you will be an expert because you have changed one bad module after another. There are plenty of "rebuilders" out there that will do it for you and offer a "guarantee". Dorman sells a rebuilt (actually used) all painted up that you can order from the local auto supply. You can try to revive the dead with module chargers.

    I suggest spending $1600 for new cells that you install diy or find a new Toyota battery for $2,000-$3000 depending on your negotiating and shopping expertise. The rebuilt (swapped modules) are available from $500 to $2,000.

    You will hear about rebuilders who don't return calls after the second failure and chargers for sale when people get tired of it. And guys who have a clean, non oil burner who just want a reliable Prius again and buy new parts that will easily last another 150,000 miles.
     
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  10. Ibrahim Dard

    Ibrahim Dard Junior Member

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    Dear Gurus, My 2014 Prius with only 75k miles driven in extreme heat (104F + Summer days) and a lot of parked with AC on usage has given me P0A80. I Measured through Dr. Prius app and recorded this very short video of few seconds (link below) showing what happens when the vehicle beeps and shows the Batter Alarm and yellow triangle. It seems i only have one bad battery block. Do you think there is a chance to extend this battery's life by services & replacing the bad cell or should I got for new battery ?
    Kind Regards,
    I live in a country where there is no Warranty from toyota so cant really claim warranty as its only 75k miles.

    Alarm moment.jpg
    Alarm moment.jpg LifeTest_2021-04-09_10-26-47.jpg
     
  11. davecook89t

    davecook89t Senior Member

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    Certainly you have one bad block, but judging by your screen shot (I can't read the values on the blocks in your video to confirm my suspicion, certainly it is advisable to have a larger sample size when deciding which modules to replace), several of the blocks in the center of the pack show relatively low voltage, and at the very least will have modules that need to be refurbished, if not outright replaced. If the Prolong (@jeff652) module balancing system can be shipped to your country, it might be worth your while to look into purchasing that to possibly save some of the modules that are getting weak but have not yet produced an error code. Clearly one of the modules in Block #6 has a shorted cell and will need to be replaced. I do not see that with the other modules in the center of the pack, but you should not wait until they become even weaker before replacing or refurbishing them.
     
  12. jdenenberg

    jdenenberg EE Professor

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    Block #6 which consists of two battery modules in series, has a reversed cell in on of it's two modules. Replacing that module will bring your Prius back to life, but unless you rebalance the whole battery pack, the repair will be temporary.

    JeffD
     
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