Stop rebuilding Prius battery packs with used modules

Discussion in 'Gen 2 Prius Technical Discussion' started by epoch_time, Feb 22, 2026 at 3:40 PM.

  1. epoch_time

    epoch_time Active Member

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    Stop rebuilding prius battery packs. Used battery modules can never be balanced to make a good rebuilt battery pack. Stop buying these rebuilt battery packs warranty or not these packs can never stay balanced longer than a few months.
    I see several used priuses on craig's list all around 120k to 160k miles all state brand new hv battery packs with warranties, albet all rebuilt packs. Good prices from 3k to 6k dollars.
    I wouldn't take any of these priuses even if given free! I can guarantee the orignal battery packs from these craigs list priuses were better ballanced than there replacements.
    Why are so many prius owners replacing there used but good balanced battery packs with plenty of life remaining (albet most with 100k miles remaining) with rebuilt junk packs good for
    1k or maybe 4k miles.
    I have a 2009 prius that I purchased new, now with 130k miles I've had an android blutooth torque apk connected continously for 12 years now. I monitor the 14 module pairs internal
    resistances. They are all within 1 milliohm some will show after long drive .028 some .027 ohms no difference more than .001 ohm. Each torque apk guage can be configured up to 3 decimal points
    of accuracy! I live in las vegas and I've been controlling the hv battery cooling fan speed using the torque apk (not recomended). Over the hot summer years I've kept the t2 battery
    temperature below 106F degrees.
    at 106F the prius goes into first current limiting stage. Unfortionatly a prius parked in the summer sun for as little as one hour will result in 122F battery temperature before even being driven!
    You want to continue rebuilding battery packs try matching modules while putting a momentary charge/discharge current of 90 amps for several seconds at a time this is the regen current
    and the discharge current under hard
    acceleration of my 16 year old hv battery pack. When you can balance the modules with 90 amp momentary charge/discharge you might have something usable otherwise forget it.
     
    #1 epoch_time, Feb 22, 2026 at 3:40 PM
  2. bisco

    bisco cookie crumbler

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    I’d buy one if the price was right and put in a new oem
     
    #2 bisco, Feb 22, 2026 at 3:55 PM
  3. BiomedO1

    BiomedO1 Senior Member

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    Definitely not a gen3; Well maybe a FREE V in decent condition. Also be willing to lose your traction battery core charge. depending on how badly the original was butchered - that's why I like FREE, which makes me feel better when I get bit in my assets....
    Congratulations; Ya seem to know what your doing; because I've given up with trying to educate people who think that a halogen headlamp bulb is a decent load test of those batteries.:(:LOL::sleep:
     
    #3 BiomedO1, Feb 22, 2026 at 4:09 PM
    Last edited: Feb 22, 2026 at 4:15 PM
  4. PriusCamper

    PriusCamper Senior Member

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    Sounds like you're financially stable enough that you can afford a brand new pack, but that makes you in the minority and not aware of the majority of old Prius owners. Apparently this is your Marie Antoinette moment....

    And yes, I agree sellers don't do a good job differentiating between a new vs rebuilt pack. I also agree that a brand new pack is essential if you're running a repair shop, in terms of permanent repairs and making sure you don't have cars coming back with the same problem your repaired.

    But the truth is rebuilt packs or simply slapping a spare module in is the only possible way most people on a limited income can still keep driving their Prius.

    Most of all you seem to not understand that professional battery rebuilders have little problem giving a 3 year warranty on their packs. Nor do you understand that slapping a spare module in that only costs $35 and not doing a full reconditioning or thorough testing can sometimes get you down the road for another year.

    As in, there's a huge number of dead Prius out there because owners can't afford a new battery pack and what you're advocating is that those cars are only good if they have a brand new battery packs, which will often cost more than the value of the vehicle, which is an incredibly wasteful assertion.

    It's not like we live on a planet of unlimited resources for all 8 billion people. As in we need to get as much value out of the cars we already have rather than forcing people to go deeper into debt buying a different vehicle because they can't afford to repair their existing one with brand new parts.
     
    #4 PriusCamper, Feb 22, 2026 at 4:49 PM
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