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BQ34Z100-G1: SOC increases with a discharge...

Charles-Elie Demarty
Intellectual 665 points
Part Number: BQ34Z100-G1
Other Parts Discussed in Thread: GPCCHEM

Hello everyone, 

I contact you because we observe a strange behavoir: at some point the "Remaining Capacity" register increases during a discharge (without change for FCC register).

Here a curve of "DSG_10min_BQ2" file:

Remarks : 

  • We discharge every 10 mins 2A for 7s.
  • Similar behavior had previously been observed (inversion of the remaining capacity). The cause was writing a negative value in the "Cc Delta" register. But the behavior was constant. In our case, what is strange is that it seems to be done in a hazardous way.

DSG_10min_BQ2.xlsx

For another battery, the voltage drops (there is a short discharge every day for months) and the SOC doesn't follow a logical behavior.

Vbat lower vs SOC higher...

 

Date

VBatt

SOC

T°C

flag_status (0x0E/0F)

05-04-2019 11:00:05

23.88

100

38.4

0x0280

05-04-2019 11:00:09

23.724

100

38.4

0x0281

08-04-2019 11:14:34

23.898

86

21.9

0x0180

23-04-2019 16:22:02

23.832

92

22

0x0180

24-04-2019 11:01:10

23.796

93

39

0x0180

The curve : 

 

Our customer and ourselves do not understand this behavior. Can you explain it?

Best regards

  • 0
    TI__Mastermind 42535 points
    I suspect that this is a result of capacity simulations during relaxation. The IT algorithm used here is old and has a few limitations. I will analyze your logs and get back to you with an answer this week.
  • 0
    Intellectual 665 points

    Hi, 

    To add a few more elements here are the customer curves.

    3438.Extract-customer.docx

    3323.Document23.pdf

    Profile customer profile is as follows : 

    -    The battery is discharged once a day during 5 seconds for a “Power Test Mode”.

    -    Discharge rate approx. 2 A

    -    Floating mode (only I2C communication) during the rest of the day

    -    Temperature (battery): 40 – 43 °C

    -    Battery is recharged if the SoC drops below 90%

    But as you can see, even after several discharges over the days, the SOC register can go down, as increase ...

    In addition, dataflash file:

    Extract 70198B-0064-W41-2017.gg.txt 
    * Texas Instruments Data Flash File
* File created Wed May 29 17:29:48 2019
*
* Device Number 100
* Firmware Version 0.16
* Build Number not available
* Order Number not available
*
* bqz Device Number 100
* bqz Firmware Version 0.16
* bqz Build Number 17
*
* Field Order: Class name, Subclass name, Parameter name, Parameter Value, Display Units
"Configuration","Safety","OT Chg","70.0","1degC"
"Configuration","Safety","OT Chg Time","2","Seconds"
"Configuration","Safety","OT Chg Recovery","65.0","1degC"
"Configuration","Safety","OT Dsg","75.0","1degC"
"Configuration","Safety","OT Dsg Time","2","Seconds"
"Configuration","Safety","OT Dsg Recovery","70.0","1degC"
"Configuration","Charge Inhibit Cfg","Chg Inhibit Temp Low","-40.0","1degC"
"Configuration","Charge Inhibit Cfg","Chg Inhibit Temp High","90.0","1degC"
"Configuration","Charge Inhibit Cfg","Temp Hys","5.0","1degC"
"Configuration","Charge","Suspend Low Temp","-40.0","1degC"
"Configuration","Charge","Suspend High Temp","90.0","1degC"
"Configuration","Charge","Pb Temp Comp","1.920","%"
"Configuration","Charge","Pb Reduction Rate","0.128","%"
"Configuration","Charge Termination","Taper Current","40","mAmp"
"Configuration","Charge Termination","Min Taper Capacity","25","mAmpHr"
"Configuration","Charge Termination","Cell Taper Voltage","200","mVolt"
"Configuration","Charge Termination","Current Taper Window","40","Seconds"
"Configuration","Charge Termination","TCA Set %","99","Percent"
"Configuration","Charge Termination","TCA Clear %","95","Percent"
"Configuration","Charge Termination","FC Set %","100","Percent"
"Configuration","Charge Termination","FC Clear %","98","Percent"
"Configuration","Charge Termination","DODatEOC Delta T","10.0","1degC"
"Configuration","Charge Termination","NiMH Delta Temp","3.0","1degC"
"Configuration","Charge Termination","NiMH Delta Temp Time","180","Seconds"
"Configuration","Charge Termination","NiMH Hold Off  Time","100","Seconds"
"Configuration","Charge Termination","NiMH Hold Off Current","240","mAmp"
"Configuration","Charge Termination","NiMH Hold Off  Temp","25.0","1degC"
"Configuration","Charge Termination","NiMH Cell Negative Delta Volt","17","mVolt"
"Configuration","Charge Termination","NiMH Cell Negative Delta Time","16","Seconds"
"Configuration","Charge Termination","NiMH Cell Neg Delta Qual Volt","4200","mVolt"
"Configuration","Data","Manuf  Date","2017-11-10","Day + Mo*32 + (Yr -1980)*256"
"Configuration","Data","Ser. Num.","0040","hex"
"Configuration","Data","Cycle Count","3","Count"
"Configuration","Data","CC Threshold","3800","mAmpHr"
"Configuration","Data","Max Error Limit","100","%"
"Configuration","Data","Design Capacity","4000","MilliAmpHour"
"Configuration","Data","Design Energy","14600","MilliWattHour"
"Configuration","Data","SOH Load I","-20","MilliAmp"
"Configuration","Data","Cell Charge Voltage T1-T2","4200","mV"
"Configuration","Data","Cell Charge Voltage T2-T3","4200","mV"
"Configuration","Data","Cell Charge Voltage T3-T4","4100","mV"
"Configuration","Data","Charge Current T1-T2","10","Percent"
"Configuration","Data","Charge Current  T2-T3","50","Percent"
"Configuration","Data","Charge Current  T3-T4","30","Percent"
"Configuration","Data","JEITA T1","0","degC"
"Configuration","Data","JEITA T2","10","degC"
"Configuration","Data","JEITA T3","45","degC"
"Configuration","Data","JEITA T4","55","degC"
"Configuration","Data","Design Energy Scale","1","Number"
"Configuration","Data","Device Name","70198B","-"
"Configuration","Data","Manufacturer Name","SAFT","-"
"Configuration","Data","Device Chemistry","LION","-"
"Configuration","Discharge","SOC1 Set Threshold","1080","mAh"
"Configuration","Discharge","SOC1 Clear Threshold","1260","mAh"
"Configuration","Discharge","SOCF Set Threshold","540","mAh"
"Configuration","Discharge","SOCF Clear Threshold","720","mAh"
"Configuration","Discharge","Cell BL Set Volt Threshold","2500","mVolt"
"Configuration","Discharge","Cell BL Set Volt Time","2","Seconds"
"Configuration","Discharge","Cell BL Clear Volt Threshold","3000","mVolt"
"Configuration","Discharge","Cell BH Set Volt Threshold","4227","mVolt"
"Configuration","Discharge","Cell BH Volt Time","2","Seconds"
"Configuration","Discharge","Cell BH  Clear Volt Threshold","4150","mVolt"
"Configuration","Discharge","Cycle Delta","2.00","%"
"Configuration","Manufacturer Data","Pack Lot Code","0000","hex"
"Configuration","Manufacturer Data","PCB Lot Code","0000","hex"
"Configuration","Manufacturer Data","Firmware Version","0000","hex"
"Configuration","Manufacturer Data","Hardware Revision","0000","hex"
"Configuration","Manufacturer Data","Cell Revision","0000","hex"
"Configuration","Manufacturer Data","DF Config Version","0100","hex"
"Configuration","Integrity Data","Static Chem DF Checksum","69f4","Number"
"Configuration","Lifetime Data","Lifetime Max Temp","48.0","1degC"
"Configuration","Lifetime Data","Lifetime Min Temp","-2.3","1degC"
"Configuration","Lifetime Data","Lifetime Max Chg Current","3030","mAmp"
"Configuration","Lifetime Data","Lifetime Max Dsg Current","-4061","mA"
"Configuration","Lifetime Data","Lifetime Max Pack Voltage","21000","20mV"
"Configuration","Lifetime Data","Lifetime Min Pack Voltage","275","20mV"
"Configuration","Lifetime Temp Samples","LT Flash Cnt","110","Count"
"Configuration","Registers","Pack Configuration","09e1","flags"
"Configuration","Registers","Pack Configuration B","f7","flags"
"Configuration","Registers","Pack Configuration C","30","flags"
"Configuration","Registers","LED_Comm Configuration","53","flags"
"Configuration","Registers","Alert Configuration","0000","flags"
"Configuration","Registers","Number of series cell","6","num"
"Configuration","Lifetime Resolution","LT Temp Res","1.0","1degC"
"Configuration","Lifetime Resolution","LT Cur Res","100","mA"
"Configuration","Lifetime Resolution","LT V Res","1","20mV"
"Configuration","Lifetime Resolution","LT Update Time","60","Seconds"
"Configuration","LED Display","LED Hold Time","4","Num"
"Configuration","Power","Flash Update OK Cell Volt","2800","mVolt"
"Configuration","Power","Sleep Current","15","mAmp"
"Configuration","Power","FS Wait","0","Seconds"
"System Data","Manufacturer Info","Block A 0","00","hex"
"System Data","Manufacturer Info","Block A 1","00","hex"
"System Data","Manufacturer Info","Block A 2","00","hex"
"System Data","Manufacturer Info","Block A 3","00","hex"
"System Data","Manufacturer Info","Block A 4","00","hex"
"System Data","Manufacturer Info","Block A 5","00","hex"
"System Data","Manufacturer Info","Block A 6","00","hex"
"System Data","Manufacturer Info","Block A 7","00","hex"
"System Data","Manufacturer Info","Block A 8","00","hex"
"System Data","Manufacturer Info","Block A 9","00","hex"
"System Data","Manufacturer Info","Block A 10","00","hex"
"System Data","Manufacturer Info","Block A 11","00","hex"
"System Data","Manufacturer Info","Block A 12","00","hex"
"System Data","Manufacturer Info","Block A 13","00","hex"
"System Data","Manufacturer Info","Block A 14","00","hex"
"System Data","Manufacturer Info","Block A 15","00","hex"
"System Data","Manufacturer Info","Block A 16","00","hex"
"System Data","Manufacturer Info","Block A 17","00","hex"
"System Data","Manufacturer Info","Block A 18","00","hex"
"System Data","Manufacturer Info","Block A 19","00","hex"
"System Data","Manufacturer Info","Block A 20","00","hex"
"System Data","Manufacturer Info","Block A 21","00","hex"
"System Data","Manufacturer Info","Block A 22","00","hex"
"System Data","Manufacturer Info","Block A 23","00","hex"
"System Data","Manufacturer Info","Block A 24","00","hex"
"System Data","Manufacturer Info","Block A 25","00","hex"
"System Data","Manufacturer Info","Block A 26","00","hex"
"System Data","Manufacturer Info","Block A 27","00","hex"
"System Data","Manufacturer Info","Block A 28","00","hex"
"System Data","Manufacturer Info","Block A 29","00","hex"
"System Data","Manufacturer Info","Block A 30","00","hex"
"System Data","Manufacturer Info","Block A 31","00","hex"
"Gas Gauging","IT Cfg","Load Select","1","Number"
"Gas Gauging","IT Cfg","Load Mode","0","Number"
"Gas Gauging","IT Cfg","Max Res Factor","50","num"
"Gas Gauging","IT Cfg","Min Res Factor","1","num"
"Gas Gauging","IT Cfg","Ra Filter","500","num"
"Gas Gauging","IT Cfg","Min PassedChg NiMH-LA 1st Qmax","92","%"
"Gas Gauging","IT Cfg","Maximum Qmax Change","96","%"
"Gas Gauging","IT Cfg","Cell Terminate Voltage","2500","mVolt"
"Gas Gauging","IT Cfg","Cell Term V Delta","200","mVolt"
"Gas Gauging","IT Cfg","ResRelax Time","500","Seconds"
"Gas Gauging","IT Cfg","User Rate-mA","0","MilliAmp"
"Gas Gauging","IT Cfg","User Rate-Pwr","0","mW/cW"
"Gas Gauging","IT Cfg","Reserve Cap-mAh","0","MilliAmpHour"
"Gas Gauging","IT Cfg","Reserve Energy","0","mWh/cWh"
"Gas Gauging","IT Cfg","Max Scale Back Grid","4","num"
"Gas Gauging","IT Cfg","Cell Min DeltaV","0","mVolt"
"Gas Gauging","IT Cfg","Ra Max Delta","15","%"
"Gas Gauging","IT Cfg","Design Resistance","196","mOhms"
"Gas Gauging","IT Cfg","Reference Grid","4","-"
"Gas Gauging","IT Cfg","Qmax Max Delta %","5","mAmpHour"
"Gas Gauging","IT Cfg","Max Res Scale","32000","Num"
"Gas Gauging","IT Cfg","Min Res Scale","1","Num"
"Gas Gauging","IT Cfg","Fast Scale Start SOC","10","%"
"Gas Gauging","IT Cfg","Charge Hys V Shift","40","mVolt"
"Gas Gauging","IT Cfg","Smooth Relax Time","1000","s"
"Gas Gauging","Current Thresholds","Dsg Current Threshold","60","mAmp"
"Gas Gauging","Current Thresholds","Chg Current Threshold","75","mAmp"
"Gas Gauging","Current Thresholds","Quit Current","40","mAmp"
"Gas Gauging","Current Thresholds","Dsg Relax Time","60","Seconds"
"Gas Gauging","Current Thresholds","Chg Relax Time","60","Seconds"
"Gas Gauging","Current Thresholds","Cell Max IR Correct","400","mV"
"Gas Gauging","State","Qmax Cell 0","4065","mAmpHr"
"Gas Gauging","State","Cycle Count","3","num"
"Gas Gauging","State","Update Status","06","num"
"Gas Gauging","State","Cell V at Chg Term","4200","mVolt"
"Gas Gauging","State","Avg I Last Run","-1930","mAmp"
"Gas Gauging","State","Avg P Last Run","-6803","MilliWattHour"
"Gas Gauging","State","Cell Delta Voltage","32","mVolt"
"Gas Gauging","State","T Rise","0","Num"
"Gas Gauging","State","T Time Constant","32767","Num"
"Ra Table","R_a0","R_a0 Flag","ff55","Hex"
"Ra Table","R_a0","R_a0 0","22","Num"
"Ra Table","R_a0","R_a0 1","29","Num"
"Ra Table","R_a0","R_a0 2","35","Num"
"Ra Table","R_a0","R_a0 3","53","Num"
"Ra Table","R_a0","R_a0 4","37","Num"
"Ra Table","R_a0","R_a0 5","41","Num"
"Ra Table","R_a0","R_a0 6","50","Num"
"Ra Table","R_a0","R_a0 7","44","Num"
"Ra Table","R_a0","R_a0 8","50","Num"
"Ra Table","R_a0","R_a0 9","54","Num"
"Ra Table","R_a0","R_a0 10","48","Num"
"Ra Table","R_a0","R_a0 11","57","Num"
"Ra Table","R_a0","R_a0 12","73","Num"
"Ra Table","R_a0","R_a0 13","189","Num"
"Ra Table","R_a0","R_a0 14","484","Num"
"Ra Table","R_a0x","R_a0x Flag","ffff","Hex"
"Ra Table","R_a0x","R_a0x 0","22","Num"
"Ra Table","R_a0x","R_a0x 1","29","Num"
"Ra Table","R_a0x","R_a0x 2","35","Num"
"Ra Table","R_a0x","R_a0x 3","53","Num"
"Ra Table","R_a0x","R_a0x 4","37","Num"
"Ra Table","R_a0x","R_a0x 5","41","Num"
"Ra Table","R_a0x","R_a0x 6","50","Num"
"Ra Table","R_a0x","R_a0x 7","44","Num"
"Ra Table","R_a0x","R_a0x 8","50","Num"
"Ra Table","R_a0x","R_a0x 9","54","Num"
"Ra Table","R_a0x","R_a0x 10","48","Num"
"Ra Table","R_a0x","R_a0x 11","57","Num"
"Ra Table","R_a0x","R_a0x 12","73","Num"
"Ra Table","R_a0x","R_a0x 13","189","Num"
"Ra Table","R_a0x","R_a0x 14","484","Num"
"Calibration","Data","CC Gain","5.417","mohm"
"Calibration","Data","CC Delta","5.408","mohm"
"Calibration","Data","CC Offset","-1389","num"
"Calibration","Data","Board Offset","-13","num"
"Calibration","Data","Int Temp Offset","0","degC"
"Calibration","Data","Ext Temp Offset","-4.4","degC"
"Calibration","Data","Voltage Divider","28142","mVolt"
"Calibration","Current","Deadband","5","mAmp"
"Security","Codes","Sealed to Unsealed","00000000","hex"
"Security","Codes","Unsealed to Full","00000000","hex"
"Security","Codes","Authen Key3","00000000","hex"
"Security","Codes","Authen Key2","00000000","hex"
"Security","Codes","Authen Key1","00000000","hex"
"Security","Codes","Authen Key0","00000000","hex"

    Thanks for you support.

    Best regards.

  • 0 in reply to Charles-Elie Demarty
    TI__Mastermind 42535 points
    Thank you Charles,

    I clearly see that the flags status of 0x281 is wrong. But that might possibly be a comm error. Can you please give me the details or your cell that you use and if you had generated a chem ID match for that?

    It is possible that a mismatch may cause issues with FCC. I don't see anything wrong with resimulated capacity, however IT requires at least a min passed chg for Qmax to be updated. In cases where this is not met, a relaxation time limit is imposed after which capacity is resimulated.
  • 0 in reply to Batt
    Intellectual 665 points

    Hello Batt,

    • Why do you say that the value 0x0281 is an error? With this there are as flag : FC - OCVTAKEN - DSG.

    For me, it cannot to have together OCVTAKEN and DSG. Yet there is this value at each discharge.

    (FC flag because SOC = 100%)

    Sometimes, we have Flags() = 0x0180. In datasheet, I cannot find information about CF flag. What are the conditions ?

    • We use 0x1323 Chem ID (MP174565xtd).
    • Without charge, the algorithm is updated every 5h?

  • 0 in reply to Charles-Elie Demarty
    Intellectual 665 points

    Hello, 

    Have you been able to study the problem?

    I come back to you comment: "The IT algorithm used here is old and has a few limitations."

    Is there more than one firmware for this component? 

    It is still a shame to have a product already "old" for a component of less than 5 years... For information, the BQ20z95 we do not have this kind of miscalculation.

     

    To help you identify the problem, here are some new data:

    data3.zip

    Looking forward to reading you

    BR.

  • 0 in reply to Charles-Elie Demarty
    TI__Mastermind 42535 points

    Thanks, Charles. I'm working with the fw developer here to understand your problem per your config. Allow me until tomorrow to respond to you.

  • 0 in reply to Batt
    Intellectual 665 points

    Hi Batt, 

    Have you been able to advance on the subject?

    Best regards.

  • 0 in reply to Charles-Elie Demarty
    TI__Mastermind 42535 points

    Hi Charles,

    Here are some notes from the developer.

    It looks like this cell been characterized with a large margin of error. The cells DOD accuracy from the GPCCHEM tool for ID 1323 must probably be high. Your config has a large cell taper window that can cause issues with chg termination. Ideally that taper voltage should be 100mV from Vmax. Your window opens at 200mV. Please change that and retry your test.

  • 0 in reply to Batt
    Intellectual 665 points

    Hello, 

    In fact, I saw that the Taper Voltage registry was too strong. We lowered it to 84mV.

    What annoys me a bit more, is the fact that our cell is not well characterized. Do you suggest characterizing the cells again?

    Something else. Reading your documents we found the Smooth function.
    In your opinion, can this help our case?

    Best regards.

  • 0 in reply to Charles-Elie Demarty
    TI__Mastermind 42535 points

    Hi Charles,

    Yes, characterizing your cell might definitely help more than using smoothing. The reason is because smoothing has 2 anchor points at 100% and 0%. It will allow a jump to either from any value. That may not fully address the issue that you are seeing. The best way is to make sure that your chem ID is correct and that will allow your DOD and gauging to be better.

  • 0 in reply to Batt
    Intellectual 665 points

    Hi Bat, 

    I'm coming back to you about cell characterization. 

    • Could you give us your procedure? 
    • Can we do this study ourselves?
    • When you characterize cells, how do you judge it is performing well or not?

    Thank you for your support.

    Best regards.

  • 0 in reply to Charles-Elie Demarty
    Intellectual 665 points

    Hello, 

    In addition, by pursuing our research, we have a new case.
    The following file explain the strange behavior in detail.

    strange behavior in storage.zip

    To sum up, the error seems to occur during a storage period. The circuit goes from 30% to 100% without charge or discharge.

    This error case is more due to a cell characterization error or the following parameters?

    • Learning Configuration of Table 28 instead of 29
      • Max Res Factor : 50
      • Min Res Factor : 1
      • Maximum Qmax Change : 96% (not 100%)
      • Max Res Scale : 32000
      • Min Res Scale : 1
    • Other point : SOH Load I : -20 instead of -400mA following TI

    Thank in advance.

  • 0 in reply to Charles-Elie Demarty
    TI__Mastermind 42535 points

    Hi Charles,

    I believe it's a cell characterization error. Also, SOH load I should be set to what could possibly be your average load. This is because the state of health is evaluated using this current. The GPCCHEM page gives you information on how to get a chem ID for your cell. This needs to be done first. Once it's done, you can run a learning cycle similar to and characterize your cell.