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Hybrid battery is dying, unsure which way to go

Discussion in 'Gen 2 Prius Technical Discussion' started by liberate88, Jun 18, 2022.

  1. liberate88

    liberate88 New Member

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    I did clean the fan, but it's still pulling hard. I'm going to clean the fan plug and see if that helps.

    The bearing is just the front right wheel, so that's not too bad. Could the brake actuator be triggered by other computer issues? Is there a way to get more information on that component or would I have to see if it comes up again after doing other fixes?
     
  2. liberate88

    liberate88 New Member

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    I'm not really certain about the ABS, and someone else said that brake codes won't show on Dr. Prius app? Perhaps I need to ask a mechanic to use their full diagnostic system? I was so focused on the battery when I first went to a mechanic that unfortunately I don't have the full diagnostic. The only code I did write down was P3000, the other things that I listed was whatever I could type down fast enough as the mechanic read them off.

    When I was looking into ABS I saw a screenshot of a prius with lots of lights on the dashboard... they had the ((!)) ABS VSC... but mine doesn't show ABS, the only thing is check engine. However, I don't totally trust my dashboard because it also doesn't ever say "ready," I thought it wasn't working properly until the check engine light came on. But maybe not showing ready means something else?
     
    #42 liberate88, Jun 26, 2022
    Last edited: Jun 26, 2022
  3. bisco

    bisco cookie crumbler

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    see post #3
     
  4. liberate88

    liberate88 New Member

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    Okay folks another update if you’ll bear with me!

    I cleaned the fan plug. I didn’t have the best tools so I’m going to do a more thorough job (used rubbing alcohol and paint brush), but it worked! The fan stopped blowing at high speeds. I feel really proud of this small thing, thank you everyone.

    Then I took her for a test drive. She charged! To full green bars! She accelerated quickly and normally after a full stop. The engine went off at lower speeds.

    Then I got back and plugged the OBD in and got new readings. The first photo is the car with just electrical running, the second is with the car running, and for reference I included the old one that had #12 in the red. I included that second one to show how it went out of line of the others.

    so according to these the internal resistances are all equalized now. Unfortunately it looks like I took the first set of photos with the car on (didn’t know I had to press power twice‍♀️), so I can’t have a great comparison, but all the voltages look around the same level except for #12.

    Also before I had P3022 and P0A80, and now I just have the P0A30 (I disconnected my 12v to do the plug clean).

    where to go from here? Even though the car is running back to MY normal, it’s evident that cell 12 is out of line, and I know that my normal battery loses some charge overnight (maybe down to 3 bars). Could it be corrosion inside the battery pack? Or is that cell on its way out? I’m still going to get a scanner for ABS (thanks for pointing that out bisco, didn’t realize what “tech scanner” meant at first but now I see you gotta pay a little more for scanners with ABS capabilities).

    Thank you!!!!
     

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  5. dolj

    dolj Senior Member

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    Your IR has 'equalized' because you disconnected the 12 V battery which reset the battery ECU. 19 mΩ is the default value it uses until it can recalculate the actual IR. Expect these to go back to what you saw before in a while.
     
    ColoradoCrow likes this.
  6. DarkAlaranth

    DarkAlaranth New Member

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    It may have been a read error too, the initial bad value. occasionally I'll get a super high read (250+ ohms) on my OBD adapter that then returns to normal on next update.

    If it has managed to charge near 70%+ SOC, then it should have re-analyzed the resistance by then I would have thought.

    The high voltage at "full" and low voltage at "empty" (not actual state of course) indicated that bank is a weak cell, and would be affecting the performance of the whole pack. At high voltage it would cause the voltage to stop charging due to that bank's high voltage, and at low, trigger the engine to come back on to charge the battery. This means it dictates the amp hour of the whole pack, as you cannot discharge the other cells to get their energy as it would push the weak cell down to far, and they cannot necessarily obtain their full charge.

    Reconditioning or careful charging with a hobby charger on the two battery blades that make up that bank might work, but professional reconditioning is probably needed. The blades would need to be recovered/replaced and then balanced to the rest of the pack to ensure max capacity to do the job properly.

    Might also be worth running the Prius for a while and see if normal use manages to cycle the battery and recover some capacity. (Cycling a Ni-Mh battery can sometimes remove/diminish a memory effect that makes it look more worn then it is, might also just be stuffed too ¯\_(ツ)_/¯ ).