Module Conditioning - Not Working?

Discussion in 'Gen 2 Prius Technical Discussion' started by Metzen, Oct 12, 2019.

  1. Metzen

    Metzen New Member

    Joined:
    Sep 25, 2019
    3
    1
    0
    Location:
    USA
    Vehicle:
    2007 Prius
    Model:
    LE
    I had some modules go bad in a 2007 Prius, so I read up online and have been trying to recondition the cells as best I can based on what I've read. I also ordered 4 modules off eBay (from "Hybrid Battery World").

    This is the approach I'm using:
    1) Discharge the cell to 6 volts using two 6 volt 1154 bulbs with both elements on (pulls from 7 amps at the beginning to about 6 amps at the end). This takes about 2200 - 2300 seconds for the decent cells, and 1800 - 1900 seconds for the weaker ones.

    I rigged up a Raspberry Pi with a voltage sensor and it sounds an alarm at 6 volts (as well as keeping track of how many seconds it takes to go each 1/4 volt along the way).

    2) Do a discharge-charge cycle using a Turnigy Quad 4x6S Lithium Polymer Charger.

    It discharges down to 6 volts again (I wait 5 minutes after the 6 amp discharge, and the modules bounce back to about 7 volts in that time), then charges at 2 amps. The modules get to about 8.5 - 8.7 volts before it stops.

    Many of the original modules took about 4500 - 5500 mAh on their first cycle, and have improved to 6500 - 7500 over the course of 3 or 4 discharge - charge cycles. Pretty universally they've all improved a little more with each cycle (though some are lower then previous cycles by a bit, then go up again on the next cycle), and all but 3 ended up from 6500 - 7500 on their last cycle. The 3 I plan to replace.

    However, the 2 of the 4 I ordered off eBay got 6800 - 7300 on their first cycle, then went down by 600 - 800 on the next cycle, and down another 600 - 800 on the third cycle.

    Now to the questions:
    1) Is my methodology sound for a DIY setup (even if it isn't ideal)?

    2) Did the eBay batteries come good (perhaps already reconditioned on professional equipment) and I'm somehow damaging them with my method? Or is my method just showing their existing weakness and they wouldn't have held up great in use anyway?
     
  2. Metzen

    Metzen New Member

    Joined:
    Sep 25, 2019
    3
    1
    0
    Location:
    USA
    Vehicle:
    2007 Prius
    Model:
    LE
    Am I missing necessary information to get a reply on this, or not asking the question right?
     
  3. Elektroingenieur

    Elektroingenieur Senior Member

    Joined:
    Jan 8, 2017
    2,336
    3,094
    9
    Location:
    California
    Vehicle:
    2016 Prius
    Model:
    Three Touring
    I think there aren’t all that many PriusChat members with real expertise in HV battery reconditioning, and if none of them happened to see your posting and have time to respond, I’m afraid you may not get an answer.

    The rest of us are either ignorant of it, or regard it as similar to rejuvenating picture tubes: not a sufficiently long-term fix to be worth the effort, when new batteries are available at reasonable cost from Toyota and others, and there is a recovery and recycling program for the old ones.
     
    SFO likes this.
  4. Raytheeagle

    Raytheeagle Senior Member

    Joined:
    Jul 1, 2016
    11,248
    15,429
    0
    Location:
    Bay Area, California
    Vehicle:
    2019 Prius Prime
    Model:
    Prime Plus
    Welcome to Prius Chat (y).

    Your post may have gotten lost in the shuffle:(.

    What do the serial numbers say on the top of the eBay ones?

    I don’t think you are damaging them, it just might be the test;).

    I’ve only done full pack charging and reconditioning, so I’m not the best on the individual cell maintenance. But I’ll bump this so others get a shot to help:).

    Good luck and keep us posted (y).
     
    SFO likes this.
  5. donbright

    donbright Active Member

    Joined:
    Feb 17, 2018
    171
    108
    33
    Location:
    oklahoma
    Vehicle:
    2007 Prius
    Model:
    Two
    i would be very grateful if anyone could point to any scientific or scholarly paper that describes the electrochemical process that occurs during reconditioning.
     
  6. Raytheeagle

    Raytheeagle Senior Member

    Joined:
    Jul 1, 2016
    11,248
    15,429
    0
    Location:
    Bay Area, California
    Vehicle:
    2019 Prius Prime
    Model:
    Prime Plus
    What you’re doing by reconditioning is breaking each cells “memory” by taking the cells outside of their normal range;).

    @jeff652 built his business off of making this process easy and repeatable (y).
     
    SFO, jeff652 and Prodigyplace like this.
  7. Prodigyplace

    Prodigyplace Senior Member

    Joined:
    Nov 1, 2016
    11,698
    11,296
    0
    Location:
    Central Virginia
    Vehicle:
    2017 Prius
    Model:
    Two
    @TMR-JWAP has done a lot sold reconditioning at the module level I believe.
     
    SFO and Raytheeagle like this.
  8. SFO

    SFO Senior Member

    Joined:
    Feb 7, 2017
    4,772
    4,073
    0
    Location:
    Northern California
    Vehicle:
    2007 Prius
    Model:
    N/A
    Did your setup allow for the compressing of the modules during the process?

    Though I have no real expertise in such, it seems that you might be hitting the modules a little hard with the amperage. Hopefully someone else can chime in on the proper protocol. Personally, I like to think less is more.
    Not sure if professional equipment was used, or of the sellers reconditioning methodology. There is also the possibility of the modules being sold as good, when they were actually bad. Since they're already believed to be questionable, it might be best to cycle them a few more times and see if they regain some capacity. If they are bad, you might try and have them exchanged by the seller, and or leave the appropriate review and rating for the seller.
     
    Raytheeagle likes this.
  9. Metzen

    Metzen New Member

    Joined:
    Sep 25, 2019
    3
    1
    0
    Location:
    USA
    Vehicle:
    2007 Prius
    Model:
    LE
    Thanks for the replies, everyone. Sorry for the slow response, work and life have been hectic.

    In the end I reconditioned all of the modules as good as I could, only replacing one of my modules with the best replacement module. After letting it settle for 24 hours wired up as one big 7.7v battery I put it back together and installed it, and everything works really good.

    The battery is as strong as it has been since we've owned the car (about 5 years and 40,000 miles) and the car is quite spunky. The battery seems to have as much or more capacity, judging on how long it takes to charge to fully green (coasting in B down a long, long hill by our house) and the fact that going from 0 - 60 at full throttle on a full battery only drops it down by one bar.

    So even though it was VERY time consuming I'd say it was worth it (if it lasts). If we can stretch the life of the car out another 18 months it will have been worth it. Reconditioning the modules individually definitely makes a big difference, and I think switching the inside modules to the outside and vice versa (basically going from 1 - 28 to 15 - 28 / 1 - 14) also helped. If I have to play whack-a-mole a time or two to replace other dead modules, so be it. Beyond that we'll either have to put in a new battery or sell the car. Given that it burns a quarter to a half a quart of oil a week it will almost certainly be the latter.
     
    kdfchannel likes this.
Loading...