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BQ34Z100-R2: Battery chemistry OCV table

Piotr Radecki
Prodigy 50 points
Part Number: BQ34Z100-R2
Other Parts Discussed in Thread: BQSTUDIO, GPCCHEM

Tool/software:

Hi!
I am using bq34z100r2 as a fuel gauge for NiMH battery pack BK-310CHU (4s1p).
I've managed to carry out a succesfull learning cycle.

However I observed that after fuel gauge reset it's unable to determine SOC from OCV.
It shows values near 90% while real SOC is about 15%.

I'm using battery chemistry for my cell (0x0643).

My understanding is that I might need to match battery chem using your chemical ID matching tool.
But is it normal that discrepancy is that big?

Is it somehow possible to take a look at chemistry file and compare it with OCV table from manufacturer?

KR,

Piotr

  • 0
    TI__Mastermind 25855 points

    Hello Piotr,

    I would recommend to select the right ChemID in the BQStudio that matches your Cell. TI has a vast library of cell characteristics recorded however if you can't find your cell than you can also send it to TI to generate a ChemID aswell. However, a discrepancy that big can be link to your lack of lack of chemID but make sure that your setting in BQStuido's in the register tab has the right termination voltage, QMax, Charge taper current and etc.



    Thank you,
    Alan

  • 0 in reply to Alan Frias
    Prodigy 50 points

    I mentioned in my question that I did choose the proper Chem ID.
    I did program it.
    I don't think other things you mentioned may affect OCV measurement.

    So let me repeat. Is it possible to somehow take a look and analyze the OCV curve which I programmed?

  • 0 in reply to Piotr Radecki
    Prodigy 50 points

    I can give you an example.
    Today on fully relaxed pack, I measured 5264mV, which is 1316mV per cell.
    I am sure that there is about 15% of charge in the pack.

    However the fuel gauge shows 86% state of charge.

  • 0 in reply to Piotr Radecki
    TI__Mastermind 24851 points

    Hello, 

    Have you performed a learning cycle? How was the chemID matched, did you use the GPCCHEM tool? Can you please attach your .gg file and the report from the GPCCHEM tool? 

    Regards, 

    Jonny.