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Cell characterization

Other Parts Discussed in Thread: GPCCHEM, BQSTUDIO

After running the ChemID program and getting the GPC_report, I got the message:

Please contact your TI representative to send the cell to Dallas for characterization

My "representative" informed me that TI no longer has reps! So, what is the current procedure?

The cells are Energizer "NH15 1.2V NiMH-HR6" rated at 2300 mAh and are quite common. My specific interest is in being able to set up the b134Z100-g1 as a fuel cell in low current applications.

My e-mail is: dave@pfaltz.com

Thanks

  • David
    Please attach the files that you submitted to the GPCCHEM and I will check them.

    Tom
  • Hi Tom,

    Simple question: How do I attach a file to the post?

    Thanks, Dave

  • There should be a Rich Text comment below the data entry window. You can click it and then you should be able to drag the file into the window.
  • Hi Tom,

    I must be daft - or something. I'm using Firefox on Windows 7.

    Below the window where I'm typing this text, I see only the Tags window, the check for notification of replies, the spot for BCC to other, the check box for "Suggest as an answer" and the '"Post" button. No area for comments...

    Do I need to use another browser or have some option turned on?

    Thanks, Dave

  • I use Firefox, so that is not the issue. This is the Rich text comment that I mentioned. If you do not see this, then you should be able to drag the file into the window or click the paper clip to upload the file.

  • Hi Tom,

    In my case, the "Use rich formatting doesn't how. When I follow the paper clip approach, here's what I got. Maybe it's working, but it's not obvious to me.

    Thanks, DavePitchforkBattery.zip

  • Dave,

    I cleaned up the data and ran the GPCCHEM tool. It predicts ChemID 6107 to be the best candidate.

    Tom

    4150.GPC_report.txt
    Chemistry ID selection tool, rev=2.21		
    		
    Configuration used in present fit:		
    ProcessingType=2		
    NumCellSeries=1		
    VoltageColumn=1		
    CurrentColumn=2		
    TemperatureColumn=3		
    ElapsedTimeColumn=0		
    		
    Best chemical ID : 6107	Best chemical ID max. deviation, % : 9.64	
    		
    		
    		
    Summary of all IDs with max. DOD deviation below 3%		
    		
    Chem ID	max DOD error, %	Max R deviation, ratio
    0	0	0
    		
    Warning: Deviation is above recommended level. New chem ID needs to be released for this cell. Please contact your TI representative to send the cell to Dallas for characterization		
    		
    		
    Selection of best generic ID for ROM based devices like bq274xx		
    		
    		
    Device / Family #1		
    Generic Chem ID	Device/ Voltage/ Chemistry	max DOD error, %
    312	bq27421-G1B: 4.3V LiCoO2	100
    354	bq27411-G1C: 4.35V LiCoO2	200
    3142	bq27421-G1D: 4.4V LiCoO2	200
    128	bq27421-G1A: 4.2V LiCoO2	200
    Best generic ID 312		
    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, %
    1210	bq27621:  (ALT_CHEM1) 4.3V LiCoO2	100
    354	bq27621:  (ALT_CHEM2) 4.35V LiCoO2	200
    1202	bq27621: (default) 4.2V LiCoO2	200
    Best generic ID 1210		
    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	100
    3142	bq27426: (ALT-CHEM2) 4.4V LiCoO2	200
    1202	bq27426: (ALT_CHEM1) 4.2V LiCoO2	200
    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		
    		
    		
    

  • Hi Tom,

    That's the same result I got. Which leaves the questions:

    Is a Max deviation of 9.64 acceptable?

    You mentioned that you "cleaned up the data". I have noted a lot of errors during the data collection process. Is this typical?

    When I wrote firmware that runs on my board and collect just the time, voltage, and current, (temperature dummied in), I get good clean data. My feeling is that bqStudio is trying to accomplish too much and thus muddying the waters.

    I have other questions related to my specific application, but will open a new thread for that.

    Thanks, Dave

  • I did not try the file before cleaning it up, so it must not have made a difference. We recommend keeping the max deviation below 10% for LiFePO4, PbA and NiMH cells, so you are right on the edge. Running a discharge at C/20 or C/50 may help improve the accuracy.