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Does my battery need charging or can it be charged?

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by DougsPrius, May 6, 2017.

  1. DougsPrius

    DougsPrius New Member

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    Right now these are the readings I'm getting off each module of a hybrid gen 2 battery.

    Would you consider charging any of these individually, as a whole or just install as is?
    (*********) indicate modules I might concerned about.

    closed = 12v bulb load on individual modules during testing.

    1. 5.78 open circuit, 4.18 closed circuit **********
    2. 7.46 open, 7.2 closed
    3. 7.46 open, 7.3 closed
    4. 6.24 open 5.1 closed **********
    5. 7.46 open, 7.2 closed
    6. 7.45 open, 7.15 closed
    7. 7.36, 7.20 ************
    8. 7.44, 7.20
    9. 7.15, 6.98 ************
    10. 7.44, 7.20
    11. 7.44, 7.20
    12. 7.44, 7.25
    13. 7.44, 7.15
    14. 7.44, 7.31
    15. 7.44, 7.22
    16. 7.43, 7.30
    17. 7.44, 7.30
    18. 7.45, 7.33
    19. 7.45, 7.20
    20. 7.45, 7.25
    21. 7.30, 7.00
    22. 7.44, 7.20
    23. 7.43, 7.20
    24. 7.46, 7.35
    25. 7.46, 7.30
    26. 7.45, 7.20
    27. 7.46, 7.20
    28. 7.20, 7.00 ***********
    Thanks for your help!
     
    #1 DougsPrius, May 6, 2017
    Last edited: May 6, 2017
  2. bisco

    bisco cookie crumbler

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    if it is working okay, i would get a grid charger from prolong and exercise it regularly.
     
  3. RobH

    RobH Senior Member

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    #1 & #4 look like they have dead cells. #7 & #9 are clearly out of balance, but might be usable after full rebalancing.
     
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  4. DougsPrius

    DougsPrius New Member

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    Can the dead cells be charged to be good again?


    Merged posts, use multi quote


    Is rebalancing the same as charging?
     
    #4 DougsPrius, May 6, 2017
    Last edited by a moderator: May 7, 2017
  5. Patrick Wong

    Patrick Wong DIY Enthusiast

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    No.

    Rebalancing implies that the two modules in question are charged so that they demonstrate similar behavior as the other good modules.
     
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  6. SFO

    SFO Senior Member

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    Are positive results better seen when rebalancing a battery pack with a Prolong charger, or would it be best to remove the cells/modules and rebalance them individually before reassembly and reconditioning at the pack level?

    How does one know when to only rebalance a battery pack (including the soaking charge) verses reconditioning a battery pack by rebalancing and then discharging to different voltage levels (.8v, .5v, .1v) multiple times.

    Thank you! :)
     
  7. jerrymildred

    jerrymildred Senior Member

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    It looks to me like two bad cells. Whether you replace them or not, it should be grid charged. I would first do a full reconditioning with the Prolong grid charger and then recheck the cells. If they still look bad, replace them and recondition again with the grid charger. It will get your voltages very even if you use it properly and will be a whole lot faster and easier than taking the battery apart for individual charging. Still, plan one or two weekends for it.