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Gen II Prius Individual Battery Module Replacement

Discussion in 'Gen 2 Prius Technical Discussion' started by ryousideways, Apr 24, 2013.

  1. ryousideways

    ryousideways Member

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    Setting it up as parallel was kind of an experiment with the main goal of not allowing the positives or negatives to accidentally make contact. I was also low on speaker wire. The black wire on the opposite side of the car was the best design.

    That would work just fine. That is what I ended up doing on one side.

    You need to take the time to balance the batteries. I learned the hard way that balancing is required so I had to tear my prius apart a second time. With no car in the meantime, you will have to break out the old bicycle...
     
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  2. wegortw

    wegortw Junior Member

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    Well against everyone's advice and maybe because I like to learn things the hard-way I decided not to balance the batteries (not reassembling the interior). So it sounds like I will know if this works for me or not after 15-120 test miles (or 3,000+), right?

    In the meantime I am going to play with the Android Torque app with the custom PIDs to see if I can monitor the voltage of the packs. Oh and air up my bike tires :)
     
  3. sampathkumar

    sampathkumar New Member

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    John - do you know somebody in manchester, connecticut area to do a individual module replacement. its battery block 11. p3021.
     
  4. Britprius

    Britprius Senior Member

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    I'm afraid I know a number of people in Manchester, but that is Manchester UK not US sorry.

    John (Britprius)
     
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  5. Pchan

    Pchan New Member

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    Can't wait for a detailed write up. Hopefully with more pictures. I checked the voltages on my cells and found one at 6.4. but now am trying to figure out where to go from here besides ordering a new cell.
     
  6. ryousideways

    ryousideways Member

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    Sorry I have not taken the time to put one together yet.

    Tips:
    • Make sure to load test your modules with a 55w DC halogen bulb (a car headlight). To do this wire the bulb using alligator clips to the bulb. Use your volt meter while the light bulb is on.
    • Write down your voltage results on a sheet of paper or spread sheet.
    I had to replace two modules at once. This helped me determine the second one that needed replacing.

    My previous post should help. Gen II Prius Individual Battery Module Replacement | Page 2 | PriusChat

    If you are in central Florida I may be able to help. If not try checking on facebook to see if any of your friends have the chargers you need. Otherwise you will have to drop about $250 on 8 chargers. You can get away with 4 but it will take longer. You will also need to find a way to power the chargers. If you have a spare computer power supply, convert it to a DC power supply and use that. I used a 450watt computer power supply and a car battery to power 8 chargers.
     
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  7. Pchan

    Pchan New Member

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    Thanks, I think I will try a load test first since its the easiest to start with. I will buy the thunder t6 as you recommended when I get the money.
    I have a question. You numbered all your cells. Which one is considered number one?. I marked all mine and marked my number one closest to the maintenance plug.
    In the meantime im going to soak some of the the terminal in vinegar to get the corrosion off since they pop out of the buss bar.
     
  8. Pchan

    Pchan New Member

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    ok I load tested each cell with a 55 watt halogen bulb. I alligator clipped the bulb to the positive and negative of the cell than put my meter on the terminal. These are the readings I got. Cell #14 needs to be replaced but am suspicious of 1 and 28. what do you guys think?

    1) 7.41
    2) 7.53
    3) 7.59
    4) 7.55
    5) 7.53
    6) 7.56
    7) 7.56
    8) 7.56
    9) 7.55
    10) 7.55
    11) 7.55
    12) 7.57
    13) 7.56
    14) 6.21
    15) 7.56
    16) 7.56
    17) 7.56
    18) 7.57
    19) 7.56
    20) 7.57
    21) 7.58
    22) 7.58
    23) 7.54
    24) 7.56
    25) 7.56
    26) 7.56
    27) 7.57
    28) 7.41
     
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  9. 2009Prius

    2009Prius A Wimpy DIYer

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    If I were you I would replace 1 and 28 as well - you have gone through so much trouble already, why not do them all together at once?
     
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  10. Britprius

    Britprius Senior Member

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    I would balance charge them all except module 14 as then you can make a decision knowing the capacity of all the modules.
    It is noticeable that number 14 is in the middle of the pack, and is likely to have run warmer than the outside modules and dries out faster.
    It would be a good idea to shuffle the modules when rebuilding center modules to the outside of the pack.

    John (Britprius)
     
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  11. Pchan

    Pchan New Member

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    I think I'm going to take both your advice. Replace all three and shuffle the centers to the outside. Thanks so exciting
     
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  12. Mr.Kenny

    Mr.Kenny New Member

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    How long do you leave the 55W bulb on the cell while testing?
    On my battery any cell will keep dropping in voltage as long as it is being tested.
    I suspect two cells that are lower than the others. But the range is only 7.89 to 7.62; almost all of the cells are 7.85.
     
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  13. ryousideways

    ryousideways Member

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    You only need to leave the bulb plugged in for however long it takes for your volt reader to stabilize on a reading. It will jump around until you make good contact. Mine took about 3-5 seconds to read with the bulb and voltmeter making contact.
     
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  14. Kurzweil

    Kurzweil Member

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    My '04 has 220K on it now and I am just beginning to see indications that my battery may be getting "tired". I found it down one bar (at 5 instead of 6) just traveling on level freeway and then later saw it at 7 with no more than a mild reduction in speed. I try and take it easy and am trying to make myself always idle for a half minute before starting out (up a hill).

    Regardless of the above, I see battery work in my future. I am capable of taking on the balancing task and have a friend that has done a good deal of this on Honda Insight batteries. My other two choices are a new battery from Toyota or a rebuilt one from one of the aftermarket suppliers like Reinvolt. At 220K, and particularly with my mild driving habits, I am not inclined to buy a new one unless the cost difference indicates. So I guess my question, and it should be appropriate for followers of this module string, is: Is a nine year old high mileage battery, even one obviously driven mildly, worth rehabilitating with either balancing and possible select module replacement? Or do I need to open it up and record all of the module voltages, inspect for leakage/corrosion, etc. first? Thanks.
     
  15. nh7o

    nh7o Off grid since 1980

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    The symptoms you described, changing a couple of bars, doesn't sound like impending failure by any means, although maybe you have watched this develop over time. 220K miles is certainly a good long run.

    I would suggest getting something like Priidash going, and using its data logging feature to plot the cell voltages, and have a look at what is happening. The software's author has posted examples of that. (You can also do that in varying ways with the other Prius scan tools often discussed on PC.)

    If you see more than one cell that is starting to vary from the others, then I would imagine that complete replacement would be the way to go, unless you wanted the learning experience of cell swapping, and could have the car down for a period of time.
     
  16. Kurzweil

    Kurzweil Member

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    Thanks for the Priidash recommendation. I had looked at it and did not realize that it could send individual cell voltages. That would be far easier than removing the battery and notedly safer. I have a laptop and can locate the OBDII cord. I'll await stronger indications of distress however, before proceeding.
     
  17. Britprius

    Britprius Senior Member

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    Priidash is a very useful driving aid and does give HV battery information, but feel a mini VCI with techstream may be better for your application in the long run.

    Being able to check fault codes and clear them along with brake bleeding and flushing to cover just some of it's uses may be of more help if or when you finally strike trouble.

    I am in no way degrading Priidash an extremely useful tool for a different application. As the equipment required in both cases is at minimal cost you may prefer both.

    John (Britprius)
     
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  18. ryousideways

    ryousideways Member

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    Update: Prius is still running great! I have logged over 8,000 miles on it since the rebuild/re balancing the pack. Still averaging about 48mpg.
     
  19. maverick13

    maverick13 Junior Member

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    I just wanted to say thank you. I am currently 300+ minutes into my first cycle.

    I could not figure out the Thunder T6 at first and actually charged them twice before I found out you need to be on the DISCHARGE>CHARGE Screen when you Hold Start. Hopefully they won't spaz out on me for taking them up to a healthy 8.x volts.

    I too made the mistake of just swapping one module without balancing. I took the time to rearrange the pairs to make good groupings but I learned the hard way, 120 miles, that that was not adequate enough.

    Hopefully in 3.5 days I can wire them in parallel and sync 'em. Until then I have 3.5 days to practice some soldering for the wiring harness in my head.

    Thank you.

    Here's to another 209k miles... :)
     
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  20. maverick13

    maverick13 Junior Member

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    Hey did you end up replacing #6 and #27? Were you able to get them all to 7250 mAh before the equalization process?