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2005 Prius - Hybrid battery lights again

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by ringinear, Jun 20, 2015.

  1. ringinear

    ringinear Junior Member

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    A year and a half ago, I had the hybrid battery warning lights come on and had it towed to the dealer. After given the option of replacing the battery for $4300, I took it home and did a single cell replacement (all cells ~8V, one at 6.6V which I replaced), which seemed to be all good until yesterday. Back with the warning lights and blower fan, I jumped to the conclusion that I have a similar situation, removed the battery and all cells are 8.04V +/- .05V except for 1 cell at 7.92. I am not convinced that this cell is really the culprit.
    I would appreciate any thoughts on what my next step should be here. Thanks very much.
     
    #1 ringinear, Jun 20, 2015
  2. bisco

    bisco cookie crumbler

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    it could be that under load, a cell is further off than when you take a static reading.
     
    #2 bisco, Jun 20, 2015
  3. JC91006

    JC91006 Senior Member

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    Well if you're going to play whack a mole, you should now change the one that's 7.92 volts
     
    #3 JC91006, Jun 20, 2015
  4. brucebee

    brucebee Junior Member

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    how many miles did you get before issue returned? sounds like you got a good run
     
    #4 brucebee, Jun 20, 2015
  5. ericbecky

    ericbecky Hybrid Battery Hero

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    Get a code reader.
    It should point you in the right direction
    Other possibilities:
    Same module is bad
    Different module is bad
    Too much deviation between the modules.
    Loose connection
    Corrosion
    HV leak

    Measuring the voltages under load would be more useful.
     
    #5 ericbecky, Jun 21, 2015
  6. ringinear

    ringinear Junior Member

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    Over a couple of days, the voltage (unloaded) on the one cell did go down and I replaced it with an ebay module. After a month,back with warning lights and
    Fan running constantly.
    The codes are the Port and P0A80. I am guessing that the single module replacement bought me a year or so but now need a recondition or replacement pack.

     
    #6 ringinear, Aug 2, 2015
  7. bisco

    bisco cookie crumbler

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    i concur. or get a mini vci, and go the rebalancincing route explained in other threads.
     
    #7 bisco, Aug 2, 2015
  8. ericbecky

    ericbecky Hybrid Battery Hero

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    This is a typical "Whack-A-Mole" game that is played when doing single cell replacement. Especially without periodic pack balancing to mask any imbalances. Even then it can be an ongoing challenge.

    Thanks for reporting back on your continuing saga.
     
    #8 ericbecky, Aug 4, 2015
  9. ringinear

    ringinear Junior Member

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    Thanks for all the feedback. I decided to purchase a charger and see if I can do a recondition. So I ordered a Hitec X4 charger and
    was going to try to start off with the settings I've seen elsewhere and see how it goes.

    These would be a
    (7.2V NiMH)
    Charge : 2A
    Discharge Current : .7A
    Discharge Cutoff V : 6V
    NiMH Sensitivity (delta V) : 7mV
    Waste charge time : 5 mins
    Safety Timer : off
    Capacity cut-off : 7000 mAh

    I'd appreciate any comments or suggestions on these parameters. Also, wondering if I should maybe lower the capacity cutoff since my battery has suffered some pretty warm Hawaii temperatures over the years. Thanks again for any and all advice.
     
    #9 ringinear, Aug 10, 2015
  10. bisco

    bisco cookie crumbler

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    are you studying the other rebuilding threads, or flying by the seat of your pants?
     
    #10 bisco, Aug 10, 2015
  11. ringinear

    ringinear Junior Member

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    Very much studying other posts and the rebuilding threads.
     
    #11 ringinear, Aug 10, 2015
  12. bisco

    bisco cookie crumbler

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    excellent, all the best.(y)
     
    #12 bisco, Aug 10, 2015
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