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Landed a Gen II Prius in need of repair for next to nothing

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by GC8Steve, Feb 9, 2016.

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  1. GC8Steve

    GC8Steve Junior Member

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    Just wrapped up module balancing this morning.

    Went pretty smoothly. I used a HiTec X4. Lost power once and a bit of data but another cycle showed all those modules in the green. Here's a link to the google spreadsheet with all the data for anyone interested.



    I highlighted a few suspect packs in yellow and gave them a fourth cycle after. One dropped on the fourth cycle; the only pack to behave that way.

    Recommendations on how I should move forward?

    My current plan is...
    1) Flip all modules so the +/- terminals are in line and wire in parallel to balance the pack voltages with some heavy gauge solid core copper wire.
    2) After voltage stabilizes, stack module packs with the most capacity in pairs with the strongest in the center. (Any advice here would be welcomed)
    3) Wire brush terminals and buss bars prior to re-installation, torque nuts to spec and get this thing back in the car.

    Thank you all for the guidance so far. Without the advice of the forum I'm probably be digging back into the battery pack right now with another failed module from lack of balancing!
     
    #21 GC8Steve, Mar 8, 2016
  2. strawbrad

    strawbrad http://minnesotahybridbatteries.com

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    All that will do is bring the surface charge (voltage) of the modules together. It can not move significant amp hours from one module to the next. It will have no real effect on anything.

    Brad
     
    #22 strawbrad, Mar 8, 2016
  3. edthefox5

    edthefox5 Senior Member

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    When re-assembling make sure you use some lubrication/ anti corrosion on the terminals. Wire brushing old copper will excite corrosion unless treated. Nothing rust likes better than raw shinny copper . Especially when exposed to corrosive gases. Replace the nuts also but do not use trilock nuts. No plastic on nuts.
     
    #23 edthefox5, Mar 8, 2016
  4. GC8Steve

    GC8Steve Junior Member

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    I thought this was advised to equalize voltage. Is there a different step i should take to do this or just reorder the modules as/if required and forget this step?
     
    #24 GC8Steve, Mar 8, 2016
  5. GC8Steve

    GC8Steve Junior Member

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    Wouldn't happen to know the size of these off the top of your head would you? There's a fastenal down the street from my work, I could grab some before I head home...
     
    #25 GC8Steve, Mar 8, 2016
  6. strawbrad

    strawbrad http://minnesotahybridbatteries.com

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    Putting modules in parallel will equalize the voltage. It will not bring them to the same SOC. I have tested this. The test started with five equal capacity modules in a mostly discharged state. Two were then fully charged and then all five were left in parallel overnight. At that point they all the same resting voltage. Another discharge test showed the modules that had been fully charged had retained about three times the energy of the modules that had been charged only from being in parallel.

    Brad
     
    #26 strawbrad, Mar 9, 2016
    S Keith likes this.
  7. GC8Steve

    GC8Steve Junior Member

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    I understand this Brad. I've already balanced the modules to bring them to their best individual SOC. Now that I'm reassembling the pack my understanding was that you need to equalize the voltages in the modules before you put the pack back in the car. To avoid the ECU seeing the voltage discrepancy and throwing a code.

    Sorry if I'm misunderstanding but I thought this was the correct final step before putting the pack back together and in the car.

    -Steve
     
    #27 GC8Steve, Mar 9, 2016
  8. S Keith

    S Keith Senior Member

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    Can you elaborate?
     
    #28 S Keith, Mar 9, 2016
  9. edthefox5

    edthefox5 Senior Member

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    [

    I'm sorry I don't. Try Lowes of Home D. Maybe move up to stainless nuts. Just no trilocks. Poster recently snapped a stud off using trilocks.
     
    #29 edthefox5, Mar 9, 2016
  10. strawbrad

    strawbrad http://minnesotahybridbatteries.com

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    It is really not clear what you mean.

    Within two seconds of starting your car, modules that have been parallel equalized will revert to their pre parallel state. Putting modules in parallel matches their surface charge and not the SOC. Once any load or charge is applied the surface charge is gone and what remains is the true SOC and voltage.

    Brad
     
    #30 strawbrad, Mar 11, 2016
  11. ericbecky

    ericbecky Hybrid Battery Hero

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    And once again, I will trot out this video showing exactly what strawbrad is talking about.
     
    #31 ericbecky, Mar 11, 2016
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