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Hybrid Battery Re-balancing - How important is SOC?

Discussion in 'Gen 2 Prius Technical Discussion' started by Jimmy Lam, May 22, 2020.

  1. Jimmy Lam

    Jimmy Lam New Member

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    Hey guys,

    So i'm just in the final stretch (hopefully) of repairing my hybrid battery. HUGE thanks to everyone on this forum for all the knowledge and help!

    I've already load tested, replaced the bad modules. and cycled all the batteries, and am in the process of balancing the pack. From what I gather, I should match the blocks according to capacity. I then need to connect the modules in parallel for a day to equalize the voltages before putting the pack back into the car.

    HOWEVER, do I need to make sure that the modules are all in the same state of charge before reinstalling? They're all currently fully charged. If so, what would be the best way to do this? (I've thought about individually discharging and charging each module up to say 4000mAH but this seems tedious).

    Any help would be so greatly appreciated!
     
    #1 Jimmy Lam, May 22, 2020
  2. dolj

    dolj Senior Member

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    This procedure has fallen out of favor as it doesn't really accomplish anything, so save yourself some time and skip it.
    Discharge them down to the same voltage. 7.8/7.9 V is a good target. As long as all the modules are 0.1-0.2 V of each other the BMU won't be too worried.
     
    #2 dolj, May 23, 2020
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