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2011 Prius P0A80 battery cell testing?

Discussion in 'Gen 3 Prius Technical Discussion' started by LDM, Oct 9, 2017.

  1. LDM

    LDM New Member

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    hi guys! I will cut to the chase and make this short, so like a lot of us, got me a P0A80 code, and need your advice on how to load test each battery cell, I got it out the car, and tested each cell with a multimeter, I got 7.8 and 7.9 and all of them, so could not detect an obvious bad cell that way..reading different post, I found out about load testing, by checking voltage connecting a close circuit on each cell using a light bulb. my question:
    anybody has a step by step on how to perform these tests? what kind of home bulb can I use? any help!
     
    #1 LDM, Oct 9, 2017
  2. 4md

    4md Member

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    Headlight bulb - 12v. You can use 55w, but if you find more powerfull it will be better.

    Just connect the voltmeter and check if there will be an instant big voltage drop when you connect the load.

    Create a table and write down each cell voltage before the load and after 10 seconds with load for example.
     
    #2 4md, Oct 13, 2017
    mjoo likes this.
  3. JC91006

    JC91006 Senior Member

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    Just let the modules sit for 1 week, you'll be able to see the bad module
     
    #3 JC91006, Oct 13, 2017
  4. priusb78

    priusb78 Member

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    Better connect high and low beam of the 12V bulb and you have a higher load of approx. 5 amps.
    Measure and write down voltage of each cell (better call it module, as a module is made of 6 cells) before the test.
    Take a stop watch and connect the bulb to each module for exactly 120 seconds.
    Measure the voltage immediately after the 120 seconds.

    Voltage drop usually is in the range of 0.15-0.3 volts. If a module is bad you'll see a higher drop compared to the others.
    Giving the pack a rest of a few days before testing is a good idea.
     
    #4 priusb78, Oct 15, 2017
    sovannaroeun likes this.
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