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HV Battery change help needed

Discussion in 'Gen 2 Prius Main Forum' started by Celticprius, Jul 23, 2017.

  1. Celticprius

    Celticprius New Member

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    2005 Prius
    Model:
    Four
    Greetings from damp Cornwall..on my 2005 Prius the red triangle came up, along with VSC and engine management lights, I called the RAC and the code all said the HV battery needed replacing, Toyota is not an option for me, so I purchased a used HV battery from a breaker for £180...seemed a good deal, anyway I swapped the battery, but when I tried to start the car the 12volt aux battery died..almost like there was a dead short, so I swapped the HV battery again for my old one and the car came back to life again..albeit with the warning lights still on, now I used the battery ECU that was on the new (used) battery, should I have swapped the ECU over? and I used my orange safety plug, are they coded in some way? any advise greatly received folks, I have done something wrong but cant see what.
     
    #1 Celticprius, Jul 23, 2017
  2. Celticprius

    Celticprius New Member

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    Forgot to add, the replacement battery is from a 2008 car, mine is 2005, does that make a difference?
     
    #2 Celticprius, Jul 23, 2017
  3. ericbecky

    ericbecky Hybrid Battery Hero

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    Sounds like you did things correctly.
    No need to swap over your old Ecu.


    Perhaps the one from the breaker is faulty?
    Did they provide a warranty against it being Dead On Arrival.

    You could open up the breaker pack and see if you see anything obviously wrong.
    Check the Ecu on breaker pack for corrosion or other obvious signs of problems.

    Or you could swap over the old Ecu.

    Sounds like you are getting good experience in swapping Prius packs in out of cars. Maybe you can start posting ads up as a side business soon. Lol.
     
    #3 ericbecky, Jul 23, 2017
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  4. fotomoto

    fotomoto Senior Member

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    I suspect the pack from the breaker is either bad or has been sitting for too long and has too low of a SOC (state of charge) to start the ICE (gas engine). You would need special equipment to charge that pack back to proper levels.
     
    #4 fotomoto, Jul 23, 2017
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  5. Celticprius

    Celticprius New Member

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    Vehicle:
    2005 Prius
    Model:
    Four
    Thanks for your replies guys, the battery from the breakers is indeed DOA, I stripped my battery today and found most cells around the 7.9 - 8 volt region, except 1 cell that was 6.2 volt, so I am guessing that cell needs replacing, whilst I was about it, I checked the cells on the breaker battery, they were showing around the 2 volt area, except one that was reversed polarity? anyway, the breakers battery is going back tomorrow and I guess I just need to buy one cell and replace it, is that correct?
     
    #5 Celticprius, Jul 23, 2017
  6. ericbecky

    ericbecky Hybrid Battery Hero

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    You can replace one module.

    Knowing full well that you will need to do it again in the future. (over and over)

    May as well buy a few extra modules at the same time so you are ready. Would be nice if they were from the same pack at least. Helps to reduce the variability of module characteristics.

    Now begins your game of Whack-a-mole.
     
    #6 ericbecky, Jul 23, 2017
  7. fotomoto

    fotomoto Senior Member

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    You should load test the other modules to see if there are more weak ones. Ideally you need to balance the new, used module(s) with the whole pack before reinstallation. That's what I did and got another year of the pack before finally replacing with a new Toyota pack. Details here: My P0A080 fault code and battery rebuild | PriusChat

    GOOD LUCK!
     
    #7 fotomoto, Jul 23, 2017
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