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How much voltage difference between blocks will the Gen 1 Prius tolerate?

Discussion in 'Generation 1 Prius Discussion' started by trseven, Nov 19, 2012.

  1. trseven

    trseven Junior Member

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    Location:
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    Vehicle:
    2004 Prius
    Model:
    II
    Just finished my "seems like forever" pack rebuild for a friend of mine. Had to replace 4 cells, charge cycled all, matched low with high capacity. Made a harness to put the whole thing in parallel and let sit for 4 or 5 days. Then had some ECU issues and had to replace a few opto-isolators. Took over 2 months. After I got the pack back in and buttoned up, drove it around for about 50 miles no problem. Checked the pack with the laptop, noticed I had a few low blocks and a few high blocks. Total difference about .4V, I know it shouldn't be more than .2. Should I take the whole thing apart and rebalance? Will it eventually post a code? Thanks!

    Gerry
     
    #1 trseven, Nov 19, 2012
  2. usnavystgc

    usnavystgc Die Hard DIYer and Ebike enthusiast.

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    Four
    Well, the tolerance is .3 so I'm amazed it hasn't thrown a code yet.

    My estimation is that it will eventually throw a code if the difference stay @ .4V. I wouldn't take it apart and rebalance until I got the code b/c that's too much work for a maybe.

    Who knows, maybe the system will balance to w/in .3V over time. It sounds like you did a good job of balancing the pack. I would give it some time. I would try to cycle the charge from low to high (using driving techniques) a couple of times and recheck to see if anything changed.
     
    #2 usnavystgc, Nov 19, 2012
  3. trseven

    trseven Junior Member

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    Location:
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    Vehicle:
    2004 Prius
    Model:
    II
    Thanks! Yeah, the pack does seem strong. Have a little over 50 miles since I got it together and got 52mpg on the readout. After I posted I looked up the battery ECU codes and found this one:
    P3006 - Battery SOC are uneven

    P3006 - not too sure about this, but criterion appears to be maximum permitted difference between highest block voltage and lowest block voltage at any instant (not including transients) is 1.2 volts.

    I guess if the guy that posted them is correct I may be alright!

    Thanks again!
    Gerry
     
    #3 trseven, Nov 19, 2012
  4. trseven

    trseven Junior Member

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    Location:
    Council Bluffs, Iowa
    Vehicle:
    2004 Prius
    Model:
    II
    Hey, you were right, I drove it about 40 more miles (mostly city) and checked again. Now it is about .2 off from the high block to the low. I sent it on its way with my friend Tom. Hope it gives him many trouble free miles!

    Gerry
     
    #4 trseven, Nov 20, 2012
  5. usnavystgc

    usnavystgc Die Hard DIYer and Ebike enthusiast.

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    Four
    That's great news. I figured it might do that since you took the time to ensure a good balanced pack. I predict many trouble free miles for him.
     
    #5 usnavystgc, Nov 20, 2012
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