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Recharging Cells

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by TwoPriusInTenn, Sep 8, 2019.

  1. TwoPriusInTenn

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    I am interested in recharging the hv battery cells. What is the process? Are there any videos on how to do this? What equipment/charging system is needed? Any info is appreciated.
     
  2. Raytheeagle

    Raytheeagle Senior Member

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    When you say recharging, do you mean:

    • Reconditioning?
    • Do you want to do this all at once?
    • Do you have a dash light indicating an issue?
    • Seeing early signs of battery failure?
    Good luck and keep us posted (y).
     
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  3. tankyuong

    tankyuong Senior Member

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    Cheap way would be a hobby charger
     
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  4. TwoPriusInTenn

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    Reconditioning. Bring them back up to as full a charge as possible.

    I have some cells I've taken out/replaced that I would like to do this with.

    Main question, how is this done? Step by step would be helpful.
     
  5. iskoos

    iskoos Active Member

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    If you will be charging each of the 6-cell individual module (There are 28 of them in Gen 3), a very simple hobby charger or any computerized charger can easily do it. But you need to remove the Hybrid battery unit. Yo do not need to remove each of the 28 modules but the whole unit needs to be out of the car on the table.
    If you want to charge the whole unit all at once (I would not recommend), then you will need an expensive high voltage charger.
     
  6. ASRDogman

    ASRDogman Senior Member

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    Have you thought about the Prolong charger?
    Or is it too much money?
    I wonder, if you put two batteries series, making 12-14 volts, could you use an AGM charger???

     
  7. TwoPriusInTenn

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    Cells would be done individually as they are out of the pack now. I think I read somewhere on here that they must be drained before recharging. If so, how is this done? Any recommendations on an inexpensive charger?
     
  8. iskoos

    iskoos Active Member

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    You don't need to drain them. NiMH cells don't suffer from memory effect much.

    Just get a wall adapter something with 9volts and 500-700mAh range and it should charge each module over night.(About 10-14 hours depending on their charge level). Leaving it on charge for a few hours extra will not hurt the modules as this is considered a slow charge.
    Do not try to fast charge those modules as NiMHs do not like fast charge and old cells will also have higher internal resistance which will not help.
     
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  9. ASRDogman

    ASRDogman Senior Member

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    Doesn't the Prius fast charge the battery?
     
  10. iskoos

    iskoos Active Member

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    It does and it does it super fast. But there is no other option I guess. NiMH chemistry is not suitable for fast charge. We will never see them in the future EV vehicles.
     
  11. ASRDogman

    ASRDogman Senior Member

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    Eventually, they will develop a better battery, as they did when they made the NiMH.
    Mine are almost 10 years old, 179,000 miles, and still going strong. :)

    I would imagine with a battery designed for continual fast discharging/charging, they will
    last even longer. But what would they cost?
     
  12. iskoos

    iskoos Active Member

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    Mines are 10 years old as well with 160k miles on them. They are working but I started realizing they lose voltage quicker under load (especially when below 4 bars) than before. The entrance of my neighborhood has bunch of speed pumps, one cannot go any faster than 15-20mph. So at that low speed, car shuts down the ICE and runs on battery. By the time I get home, I am sometimes down to 3 (or even 2 bars). I used to never get below 4 bars. So they aren't keeping charge as they used to but so far I didn't get any codes. (Fingers crossed). I will though (as a preventative maintenance) open up my hybrid pack and measure each of those 28 modules to see how they are doing...
     
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  13. Raytheeagle

    Raytheeagle Senior Member

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    Those signs are the early warnings signs of the pack failing;).

    That’s why I bought the Hybrid Automotive equipment at 150 k miles on our 2010 :).

    Helped ensure our 2010 battery worked well until we sold it at 200k miles(y).
     
  14. iskoos

    iskoos Active Member

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    What is that?
     
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  15. ASRDogman

    ASRDogman Senior Member

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    I haven't notice any change in my charging/discharging time.
    90% of my driving in highway driving so maybe that keeps a steady charge on them?
    I HATE SPEED BUMPS! They do NOT slow anyone down, only to go over the bump.
    Then you have to go FASTER to make up the lost time!!!!

    I do have techstreem, I should do the battery test. I should do ALL the tests!
    I'm just too lazy too do it.

     
  16. Raytheeagle

    Raytheeagle Senior Member

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    http://www.hybridautomotive.com

    It’s equipment used to maintain the hv battery in a Prius:).

    The charger and Discharger can be used either for a Gen3 or Gen2 ;).

    It works well(y).
     
  17. iskoos

    iskoos Active Member

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    Very nice looking equipment but very expensive as well. I will buy me a charger to charge the entire pack one day. But not plan spending that much money. At least for now :)
     
  18. TMR-JWAP

    TMR-JWAP Senior Member

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    You don't want to do that. You need to have them all clamped together using the clamp assembly from the HV Battery. If you try to charge them, without being clamped, you had might as well just throw them away. They'll swell significantly and damage themselves.
     
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  19. TMR-JWAP

    TMR-JWAP Senior Member

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    I don't even know where to start on this....
    guess I'll start by just passing over the first sentence and focus on the later stuff...please don't do that. Using a wall adapter as a battery charger is going to look pretty stupid when you're trying to explain to the fire department why you tried to burn your house to the ground.

    If you really want to cycle your modules, please buy a charger that's designed for it. They have some weird crap called safety features manufactured into them. There's plenty to choose from. Just do a search for "hobby charger".

    If someone really feels comfortable going to sleep with some jerry rigged crap like that in your house, then more power to you. I hope you sleep light and have a very understanding family/neighborhood.
     
    #19 TMR-JWAP, Sep 9, 2019
    Last edited: Sep 9, 2019
  20. TMR-JWAP

    TMR-JWAP Senior Member

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    And for the record, I have done the "top charge" only method. Multiple times. I do quite a bit of experimenting. Significantly more than I discuss on the forum. Top charging is a stop-gap method at best. It does not last. So this part....You don't need to drain them. NiMH cells don't suffer from memory effect much....? I wouldn't bet a paycheck on that sentence..