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Need help rebuilding my Gen1 2001 Prius HV battery

Discussion in 'Generation 1 Prius Discussion' started by Mareno Rathell, Aug 13, 2012.

  1. Mareno Rathell

    Mareno Rathell Junior Member

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    I purchased a 2001 Prius with 123K miles about two weeks ago for $1000. I knew the HV battery was shot when i purchased it. I decided to see if I could rebuild the HV battery on my own.

    I'm very mechanical but not the brightest bulb in the room when it comes to batteries and anything electrical.

    So here is where I'm at so far:

    - I removed the HV battery.
    - safely rested it on 2 horses (I used horses because it would give me easy access to the bottom to remove the bottom screws)
    - Removed all 38 modules from the battery pack
    - cleaned the busses in vinegar
    - inspected each wire that connects between buss and the nut.
    - tested each battery ( one of the batteries tested at -0.1, the others tested at 6.8)
    - I don't know how to load test the modules, so I couldn't tell if they would drop dramatically under load, so I ordered 38 used replacement batteries off of Ebay. (Gen II)
    - these replacement modules were about a half inch longer than my original modules.
    - The replacement modules arrived. I cleand the terminals, tested each one and installed them.
    - Connected the battery back into the prius.
    - Installed new 12V battery from the Toyota dealer.
    - The Prius started right up.
    - Drove it around for the first time for about 10 minutes.
    - When i was driving it, the monitor in the Prius would show the engine running most of the time but sometimes it would show it charging the HV and other times charging the 12V. the engine would shut off at stop lights and resume when I pressed on the gas pedal.
    - while driving back into my driveway, all of the warning lights came on and the batttery fan kicked into high gear,
    - I can't remember the code I pulled but it was in reference to the cells being out of balance I think. I'll have to check it again tonight when I get home.
    - I removed the HV and tightened the nuts around the busses hoping the issue would be resolved.
    - I was bale to drive it only a few minutes before the issue returned.

    other issues I noticed.

    While waiting for the replacement batteries to arrive, I did the following:
    - changed the cabin filter
    - did an oil change.
    - changed the tranny fluid and removed the tranny pan to clean out the slime and clean off the magnet.)
    - changed the rear brake shoes.
    - changed the front brake rotors and pads. ( they were in awful condition due to sitting so long)
    ***when I pressed on the brakes, only the rear brakes seem to engage, not the front. I never attempted to bleed them because I know only the dealer can do that)

    My question:

    Is it possible that my issue is because I didn't do the discharge/charge for each individual module before assembly?

    Please remember, I am electrically stupid. dumb it down for me in a major way :).
     
  2. Patrick Wong

    Patrick Wong DIY Enthusiast

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    Looks like you have accomplished a substantial amount. I suggest that you need to be precise about what DTC was logged before we can offer suggestions about what you should do about it.

    It appears that you may have a separate issue relating to your brakes that will also need to be addressed.
     
  3. jdenenberg

    jdenenberg EE Professor

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  4. Mareno Rathell

    Mareno Rathell Junior Member

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  5. Mareno Rathell

    Mareno Rathell Junior Member

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    Hey Patrick, I pulled only one code: P3006, I believe that is for uneven battery cell charge. I also believe that would be directly related to the 38 modules I just installed. I'm guessing they were all at different levels of charge so the computer is freaking out because it can't charge all cells evenly. Would this be correct? If yes, how can I resolve it? Remember I'm a retard when it comes to anything electrical so please use the most simplistic words when educating me. :)
     
  6. bwilson4web

    bwilson4web BMW i3 and Model 3

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    A Prius aware, OBD scanner can read the codes returned by the battery controller as well as the voltages from the 19, module pairs. These other codes and voltages are needed to go further. However, you could measure the voltages of all 38 modules but that won't identify a broken, voltage sense line.

    GOOD LUCK!
    Bob Wilson
     
  7. Patrick Wong

    Patrick Wong DIY Enthusiast

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    Yes, DTC P3006 is logged by the hybrid vehicle ECU and shows that the traction battery ECU has reported that one or more of the 19 module pairs has reported a lower state of charge compared to the other pairs.

    How to resolve it: I suggest that you purchase a decent digital multimeter and use that to measure the voltage of each of the 38 modules. If you see that one or two modules has a lower voltage than the others, you will need a means to charge those modules.

    The modules must be kept under mechanical compression at all times during the charging process as the plastic case will heat and expand during the charging process and may explode if not compressed.

    I also suggest that you will need to read and understand the thread that Jeff has suggested. If you should find the concepts described are not understandable, then you may need to abandon the idea of a DIY project in this area and instead buy a complete new or remanufactured battery. Good luck.
     
  8. Mareno Rathell

    Mareno Rathell Junior Member

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    thanks for that info Bob, I will try and pull the battery codes tonight.
     
  9. Mareno Rathell

    Mareno Rathell Junior Member

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    Although some of the things mentioned in the links are a bit over my head, I've never abandoned a DIY project :). If I must go at it along, I shall. I will be ordering the Dynam Supermate DC6 DC Multi Function Balance Charger/Discharger 1-6 cell Lilo/LiPo/LiFe, 1 to 15 cells NiCd NiMH to help me out with this adventure.
     
  10. bwilson4web

    bwilson4web BMW i3 and Model 3

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    The maintenance manual show the difference between the minimum and maximum module-pair voltages should be no more than 0.3V. There is also a procedure that can be used to measure the range of voltages for the 19 module pairs (from memory)
    • warm-up the car - drive around for 10-15 minutes
    • backup the car so the rear wheels are against a curb - this is so it won't roll away when put in "R"
    • use an OBD scanner that records all 19 modules or the pair of minimum and maximum module voltages and minimum and maximum module identifiers - this way you can monitor the voltage differences
    • put the car in "R" - this puts a load on the battery (does not harm the car) and record the voltages
    After I upgraded my pack using a ReInvolt pack, I used Autoenginuity to record the 19 module voltages and verify the maximum and minimum module voltages over the operational range.

    Bob Wilson

     
  11. Mareno Rathell

    Mareno Rathell Junior Member

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    Great info and suggestions Bob, I will try that tonight and thanks a million for the clear easy to follow directions :)

     
  12. Mareno Rathell

    Mareno Rathell Junior Member

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  13. Mareno Rathell

    Mareno Rathell Junior Member

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    I pulled code p3015 today. I read for the 2004+ Prius that it means the #5 modules are having issues. Those only have 28 modules so I don't think I can use that as a guide. Anyone has more info on p3015.....there don't seem to be too much out there on this code.
     
  14. Patrick Wong

    Patrick Wong DIY Enthusiast

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    Don't worry about that. If you are really concerned about identifying exactly which module pair relates to DTC P3015, then you can download repair manual info at techinfo.toyota.com

    When you remove the battery cover and use a digital multimeter to measure module voltages, you will find which module's voltage is different from the others. If you only pulled one code, then only one module pair has the problem.
     
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  15. Mareno Rathell

    Mareno Rathell Junior Member

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    The P3015 code was dead on for which module was bad. P3015 was for #5 and #5 was the one registering only 11.67 (paired up) and 3.67 by itself.

    Except for the bad module that all passed when tested under load.

    starting from the end with all of the electronics these are my results in pairs (except for 19 & 20)
    1) 16.08
    2) 16.04
    3) 16.02
    4) 16.01
    5) 11.67 (8.00 & 3.67)
    6) 16.01
    7) 16.01
    8) 16.02
    9) 16.00
    10) (#19 - 8.00 & #20 - 8.00)
    11) 16.00
    12) 16.00
    13) 16.00
    14) 16.01
    15) 16.01
    16) 16.02
    17) 16.03
    18) 16.04
    19) 16.09
     
  16. Patrick Wong

    Patrick Wong DIY Enthusiast

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    Great, so if you replace that one module with another 2G module, and make sure the voltage of the replacement is in the range between 8.00V to 8.09V before you install it, there is some hope that the car will run correctly.
     
  17. bwilson4web

    bwilson4web BMW i3 and Model 3

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    When you get the "3.67V" module out and everything normalized, please take a few minutes to look closely at it. In particular, check the terminals for evidence of "O" ring problems or other physical issues. If you have access to pool pH test kit, it would be great if you can test for evidence of KOH (strong base) outside the module.

    Bob Wilson
     
  18. Mareno Rathell

    Mareno Rathell Junior Member

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    When I took the module out yesterday I did notice that it was bulging from the sides. The bulge isn't evident today. Other than that, I didn't notice anything visually out of the norm from the other modules. What does the physical issues tell?

    The place where I purchased the modules informed me today that they will ship me out a replacement tomorrow at their expense.

    I will pick up a ph test kit today.

     
  19. bwilson4web

    bwilson4web BMW i3 and Model 3

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    Thanks,
    The swelling would be from gas. The typical failure occurs from an internal short.

    The battery electrodes are separated by a plastic mesh. Everything has a saturated, KOH electrolyte that transports the hydrogen ions from one to the other electrode through the mesh. The literature says as the electrolyte dries out, the current is forced through smaller areas. Eventually, the heating at that point becomes so severe that a small part of the plastic mesh melts opening a short inside the cell. This is not a recoverable fault.

    There are six cells in each module. When one shorts, it causes the other five to see a much higher voltage . . . leading to another failure. Worse, the higher voltages on the other cells leads to more gas generation . . . and swelling the case.

    What we are looking for is evidence that of any electrolyte leakage at either terminal ... or leakage anywhere.

    Thanks,
    Bob Wilson
     
  20. Mareno Rathell

    Mareno Rathell Junior Member

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    The replacement module arrived in the mail today. The modules tested well so I installed it and so far so good. My wife and I took turns driving it around with no lights yet :)

    You guys are awesome!!!!!

    Thanks a million for guiding me through this.