Can I resuscitate a weak hybrid-battery + battery block after lack of driving?

Discussion in 'Gen 2 Prius Main Forum' started by priuslyfe, Apr 10, 2026 at 12:14 PM.

  1. priuslyfe

    priuslyfe Member

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    I'm kinda confused how to ask this question tbh. Sorry if this problem lacks clarity. I guess the I'm just trying to say I would rather not have to worry about a hybrid-battery when I have to replace an actuator anyway in one of my Prius. I have two Gen2 Prius.

    PRIMARY DRIVER: 2007 Prius has bad actuator and cannot drive but the hybrid-battery is good.

    SPARE DRIVER: 2008 Prius has bad hybrid-battery (CODES BELOW) I suspect because although I've started it semi-regularly and let it run for 30min to an hour I haven't driven it at all this past year.

    My options are:

    A) Drive the undriven 2008 Prius and resuscitate the battery (hybrid) if possible. But it has the folowing bad battery codes

    [​IMG]



    B) If the ABOVE isn't an option and I can't drive it back to health, then I would have to swap the good-HYBRID battery from my 2007 Prius to the 2008 Prius (which would leave me shopping for a new HYBRID battery for the broken 2007 Prius plus having to replace the actuator). I don't mind because the weather in Ohio is better, but would like to avoid this option. The weather in Ohio has been brutal this past winter and the 2008 Prius has had to endure the cold-weather. Mentioning this because it might affect the outcome.
     
    #1 priuslyfe, Apr 10, 2026 at 12:14 PM
  2. pasadena_commut

    pasadena_commut Senior Member

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    Seems like these are the most likely issues:
    1. The pack is just out of balance because it has not been driven enough.
    2. Corrosion on the bus bars/nuts.
    3. The indicated module has actually gone bad.
    What are the battery voltages?

    If the voltages are just outside of the "good" limits I would be tempted to fire the thing up and drive it around for a couple of hours. Just not too far from home. Then check the voltages again. I'm not entirely sure that you can get it back into balance this way though. It may still be salvageable, but only with some time on a grid charger.

    However, if the voltage on the indicated module is way off then pull the safety latch, open the pack case, and look for corrosion. At the same time measure the voltage on the bad module directly. That should settle the matter for (2) and possibly (3).
     
    #2 pasadena_commut, Apr 10, 2026 at 2:24 PM
  3. priuslyfe

    priuslyfe Member

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    Vehicle:
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    not sure the battery voltages yet. been putting off doing any thinking about it due to the weather. gonna check tomorrow morning.

    i have read about driving it and that is what I apprehensive about. Supposedly, it needs varying speeds and distances, but because of uncertainty I don't want it to die on the highway.

    BTW It has the RED TRIANGLE that pops up after some time on 20min or so.

    EDIT: not sure exactly how to read voltages yet. did battery test on Dr. Prius said block 3 bad though.

    [​IMG]

    [​IMG]
     
    #3 priuslyfe, Apr 10, 2026 at 2:54 PM
    Last edited: Apr 10, 2026 at 3:46 PM
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