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BQ40Z50-R2: Running Chemistry Identification with GPC-Tool

Part Number: BQ40Z50-R2
Other Parts Discussed in Thread: GPCCHEM, BQ40Z50

Hello,

I am currently facing some issues running chemistry identification with BQ40z50-R2.

The configuration of my battery-pack is a 4-cell LifePO4 with external cell-balancing.

I already performed a Relax-Discharge-Relax-cycle as predetermined from TI but i won't get any good results from GPC-Tool.

The log-file i got from it is attached.

Can somebody explain me how to do a proper Chemistry Identification?

Rel_Dis_Rel.log

  • Hello Jan,

    Can you share the results/report from the GPCCHEM tool? I looked at your log and the discharge looks pretty good. The only thing is that the charge may have been a bit too high of a current (maybe not fully charged), but I don't know the battery's specifications so I can't say for sure. There is also a possibility that there is no CHEMID for this battery or something close. We can do new CHEMIDs for batteries but we like to ensure that GPCCHEM is done first.

    thanks,

    Alex M. 

  • Hello Alexander,

    Thank you for your support.

    I forgot that I have to convert the Log-file in BQ-Studio after running the Relax-Discharge-Relax-cycle.

    I attached the results from BPC-Tool and it looks pretty decent.

    Jan B.

    2845.GPC_report.txt
    Chemistry ID selection tool, rev=2.52		
    		
    Configuration used in present fit:		
    ProcessingType=2		
    NumCellSeries=4		
    ElapsedTimeColumn=0		
    VoltageColumn=1		
    TemperatureColumn=2		
    CurrentColumn=3		
    		
    Best chemical ID : 456	Best chemical ID max. deviation, % : 10.06	
    		
    		
    		
    Summary of all IDs with max. DOD deviation below 15%		
    		
    Chem ID	max DOD error, %	Max R deviation, ratio
    456	10.06	0.25
    414	11.58	0.69
    448	12.74	0.58
    6106	14.08	0.34
    417	14.28	0.55
    410	14.51	0.76
    445	14.81	0.42
    		
    Max. deviations for best ID is within recommended range. Chosen best chemical ID is suitable for programming the gauge.		
    		
    		
    Selection of best generic ID for ROM based devices like bq274xx		
    		
    		
    Device / Family #1		
    Generic Chem ID	Device/ Voltage/ Chemistry	max DOD error, %
    354	bq27411-G1C: 4.35V LiCoO2	40.15
    3142	bq27421-G1D: 4.4V LiCoO2	43.11
    312	bq27421-G1B: 4.3V LiCoO2	59.88
    128	bq27421-G1A: 4.2V LiCoO2	6390.94
    Best generic ID 354		
    Warning: Generic ID Deviation is so high that it is most likely due to anomaly in the data. Please check that data files have recomended format, units and test schedule		
    		
    		
    Device / Family #2		
    Generic Chem ID	Device/ Voltage/ Chemistry	max DOD error, %
    1202	bq27621: (default) 4.2V LiCoO2	40.12
    354	bq27621:  (ALT_CHEM2) 4.35V LiCoO2	40.15
    1210	bq27621:  (ALT_CHEM1) 4.3V LiCoO2	43.12
    Best generic ID 1202		
    Warning: Generic ID Deviation is so high that it is most likely due to anomaly in the data. Please check that data files have recomended format, units and test schedule		
    		
    		
    Device / Family #3		
    Generic Chem ID	Device/ Voltage/ Chemistry	max DOD error, %
    3230	bq27426: (default) 4.35V LiCoO2	37.3
    1202	bq27426: (ALT_CHEM1) 4.2V LiCoO2	40.12
    3142	bq27426: (ALT-CHEM2) 4.4V LiCoO2	43.11
    Best generic ID 3230		
    Warning: Generic ID Deviation is so high that it is most likely due to anomaly in the data. Please check that data files have recomended format, units and test schedule		
    		
    		
    

  • Hello Jan,

    Happy to hear it was just formatting! I looked and this chemistry is a non-turbo LiFePo4, which seems about right. 10% deviation isn't great, but is useable. If you were to try again, I would try with a single cell and charge more slowly if possible. Since you are using the BQ40z50, you could try taking a single cell's voltage column from your existing log. For example, you could run the tool using cell 2 voltage and set it to 1 series cell in the configuration. The only reason I suggest this is because its fast and you may get a better result without needing to run again. Either way, it is up to you at this point. Let me know if you have anymore questions.

    thanks,

    Alex M.