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BQ76930EVM: Cell-balancing not as expected

Part Number: BQ76930EVM
Other Parts Discussed in Thread: BQ78350

It appears that the cell-balancing on the bq78350 is not working despite the voltage being within the thresholds.  Here are screenshots of the Registers and Data Memory settings of the cell-balancing.  The maximum voltage is above the cell voltage threshold,  but the CB (cell-balancing) flag is not set.  The difference between the max and min cell voltage is greater than cell balance min.  Any ideas why the cell-balancing is not currently active?

  • Hi Brian ,
    Your post has been assigned to one of our BMS experts.

    Regards,
    David
  • Hi Brian,
    Be sure you have the cell balancing enabled in data memory Settings > Configuration > Balancing Configuration.
    It looks like you have sufficient voltage difference, also check that your charge current is sufficient.
  • The Cell Balancing Bit is set in the Balancing Configuration Register.    Where is the sufficient charge current set?  I also notice that if I issue the shutdown command and then boot the board back up, it will perform the cell-balancing.  The documentation on the cell balancing described that the cell-balancing threshold is adjusted.  Could this be happening in the background?

  • Hi Brian,
    Yes, the threshold updates in the "background", it updates on the Cell Balance Interval. To understand what is happening a log would be helpful after reset through where it balances and stops. Also a gg file with all the settings rather than the picture.
  • Attached are the .gg file and .log file.  The battery was fully discharged prior to starting the log.  The cell-balancing ran intially, but at the point I stopped the log file the voltage difference between the min cell and max cell was 250mV, yet the Cell-balancing is not active.

    The .gg file extension was renamed to .txt...the website blocked the .gg extension.

    CB_settings_gg.txt
    * Texas Instruments Data Flash File
    * File created Tue Apr 17 15:19:21 2018
    *
    * Device Number 1E9B
    * Firmware Version 0.06
    * Build Number 16
    * Order Number 0
    *
    * bqz Device Number 1E9B
    * bqz Firmware Version 0.06
    * bqz Build Number 16
    *
    * Field Order: Class name, Subclass name, Parameter name, Parameter Value, Display Units
    "Calibration","Current","CC Gain","1.000","mOhm"
    "Calibration","Current","Capacity Gain","1.000","mOhm"
    "Calibration","Voltage","Cell1 Offset","0","mV"
    "Calibration","Voltage","Cell2 Offset","0","mV"
    "Calibration","Voltage","Cell3 Offset","0","mV"
    "Calibration","Voltage","Cell4 Offset","0","mV"
    "Calibration","Voltage","Cell5 Offset","0","mV"
    "Calibration","Voltage","Cell6 Offset","0","mV"
    "Calibration","Voltage","Cell7 Offset","0","mV"
    "Calibration","Voltage","Cell8 Offset","0","mV"
    "Calibration","Voltage","Cell9 Offset","0","mV"
    "Calibration","Voltage","Cell10 Offset","0","mV"
    "Calibration","Voltage","Cell11 Offset","0","mV"
    "Calibration","Voltage","Cell12 Offset","0","mV"
    "Calibration","Voltage","Cell13 Offset","0","mV"
    "Calibration","Voltage","Cell14 Offset","0","mV"
    "Calibration","Voltage","Cell15 Offset","0","mV"
    "Calibration","Current Offset","CC Offset","0","-"
    "Calibration","Current Offset","Coulomb Counter Offset Samples","64","-"
    "Calibration","Temperature","T1 Temp Offset","0","degC"
    "Calibration","Temperature","T2 Temp Offset","0","degC"
    "Calibration","Temperature","T3 Temp Offset","0","degC"
    "Calibration","Ext Cell Voltage","Ext Cell Divider Gain","5677","-"
    "Calibration","VAux Voltage","VAux Gain","5000","-"
    "Calibration","Cell Temperature Model","Coeff a1","-11130","-"
    "Calibration","Cell Temperature Model","Coeff a2","19142","-"
    "Calibration","Cell Temperature Model","Coeff a3","-19262","-"
    "Calibration","Cell Temperature Model","Coeff a4","28203","-"
    "Calibration","Cell Temperature Model","Coeff a5","892","-"
    "Calibration","Cell Temperature Model","Coeff b1","328","-"
    "Calibration","Cell Temperature Model","Coeff b2","-605","-"
    "Calibration","Cell Temperature Model","Coeff b3","-2443","-"
    "Calibration","Cell Temperature Model","Coeff b4","4696","-"
    "Calibration","Cell Temperature Model","Rc0","11703","-"
    "Calibration","Cell Temperature Model","Adc0","11703","-"
    "Calibration","Current Deadband","Deadband","3","mA"
    "Calibration","Current Deadband","Coulomb Counter Deadband","38","264nV"
    "Settings","Protection","Protection Configuration","00","hex"
    "Settings","Protection","Enabled Protections A","ff","hex"
    "Settings","Protection","Enabled Protections B","0f","hex"
    "Settings","Protection","Enabled Protections C","05","hex"
    "Settings","Permanent Failure","Enabled PF A","00","hex"
    "Settings","Permanent Failure","Enabled PF B","00","hex"
    "Settings","Configuration","Temperature Enable","0b","hex"
    "Settings","Configuration","DA Configuration","10","hex"
    "Settings","Configuration","AFE Cell Map","02f7","hex"
    "Settings","Configuration","FET Options","0021","hex"
    "Settings","Configuration","Sbs Gauging Configuration","00","hex"
    "Settings","Configuration","Smb Configuration","a0","hex"
    "Settings","Configuration","LED Configuration","00","hex"
    "Settings","Configuration","SOC Flag Config","02fb","hex"
    "Settings","Configuration","Balancing Configuration","01","hex"
    "Settings","Configuration","CEDV Gauging Configuration","0002","hex"
    "Settings","Fuse","PF SAFE A","00","hex"
    "Settings","Fuse","PF SAFE B","00","hex"
    "Settings","Fuse","PF SAFE C","00","hex"
    "Settings","Fuse","Fuse Blow Timeout","30","s"
    "Settings","Aux SMB Address","Addr Reads","3","-"
    "Settings","Aux SMB Address","SMBTAR_ADDR0","20","hex"
    "Settings","Aux SMB Address","SMBTAR_ADDR1","22","hex"
    "Settings","Aux SMB Address","SMBTAR_ADDR2","24","hex"
    "Settings","Aux SMB Address","SMBTAR_ADDR3","25","hex"
    "Settings","Aux SMB Address","SMBTAR_ADDR4","26","hex"
    "Settings","Aux SMB Address","SMBTAR_ADDR5","28","hex"
    "Settings","Aux SMB Address","SMBTAR_ADDR6","2a","hex"
    "Settings","Aux SMB Address","SMBTAR_ADDR7","2c","hex"
    "Settings","SMB Master Mode","Host Address","10","hex"
    "Settings","SMB Master Mode","Charger Address","12","hex"
    "Settings","SMB Master Mode","Alarm Timer","10","s"
    "Settings","SMB Master Mode","Charger Request Timer","50","s"
    "Settings","Manufacturing","Mfg Status init","0030","hex"
    "Protections","CUV","Threshold","2000","mV"
    "Protections","CUV","Delay","15","s"
    "Protections","CUV","Recovery","2800","mV"
    "Protections","COV","Threshold","3650","mV"
    "Protections","COV","Delay","2","s"
    "Protections","COV","Recovery","3400","mV"
    "Protections","OCC","Threshold","6000","mA"
    "Protections","OCC","Delay","6","s"
    "Protections","OCC","Recovery Threshold","100","mA"
    "Protections","OCC","Recovery Delay","5","s"
    "Protections","OCD","Threshold","-6000","mA"
    "Protections","OCD","Delay","6","s"
    "Protections","OCD","Recovery Threshold","200","mA"
    "Protections","OCD","Recovery Delay","5","s"
    "Protections","AOLD","Latch Limit","0","-"
    "Protections","AOLD","Counter Dec Delay","10","s"
    "Protections","AOLD","Recovery","5","s"
    "Protections","AOLD","Reset","15","s"
    "Protections","AOLD","Threshold and Delay","00","hex"
    "Protections","ASCD","Latch Limit","0","-"
    "Protections","ASCD","Counter Dec Delay","10","s"
    "Protections","ASCD","Recovery","5","s"
    "Protections","ASCD","Reset","15","s"
    "Protections","ASCD","Threshold and Delay","00","hex"
    "Protections","OTC","Threshold","55.0","1degC"
    "Protections","OTC","Delay","2","s"
    "Protections","OTC","Recovery","50.0","1degC"
    "Protections","OTD","Threshold","60.0","1degC"
    "Protections","OTD","Delay","2","s"
    "Protections","OTD","Recovery","55.0","1degC"
    "Protections","UTC","Threshold","0","1degC"
    "Protections","UTC","Delay","2","s"
    "Protections","UTC","Recovery","5.0","1degC"
    "Protections","UTD","Threshold","0","1degC"
    "Protections","UTD","Delay","2","s"
    "Protections","UTD","Recovery","5.0","1degC"
    "Protections","PTO","Charge Threshold","2000","mA"
    "Protections","PTO","Suspend Threshold","1800","mA"
    "Protections","PTO","Delay","1800","s"
    "Protections","PTO","Reset","2","mAh"
    "Protections","CTO","Charge Threshold","2500","mA"
    "Protections","CTO","Suspend Threshold","2000","mA"
    "Protections","CTO","Delay","54000","s"
    "Protections","CTO","Reset","2","mAh"
    "Protections","OC","Threshold","300","mAh"
    "Protections","OC","Recovery","2","mAh"
    "Protections","OC","RSOC Recovery","90","%"
    "Permanent Fail","SOCC","Threshold","10000","mA"
    "Permanent Fail","SOCC","Delay","5","s"
    "Permanent Fail","SOCD","Threshold","-10000","mA"
    "Permanent Fail","SOCD","Delay","5","s"
    "Permanent Fail","SOT","Threshold","65.0","1degC"
    "Permanent Fail","SOT","Delay","5","s"
    "Permanent Fail","Open Thermistor","Threshold","-50.0","1degC"
    "Permanent Fail","Open Thermistor","Delay","5","s"
    "Permanent Fail","VIMR","Check Voltage","3500","mV"
    "Permanent Fail","VIMR","Check Current","10","mA"
    "Permanent Fail","VIMR","Delta Threshold","500","mV"
    "Permanent Fail","VIMR","Delta Delay","5","s"
    "Permanent Fail","VIMR","Duration","100","s"
    "Permanent Fail","CFET","OFF Threshold","5","mA"
    "Permanent Fail","CFET","OFF Delay","5","s"
    "Permanent Fail","DFET","OFF Threshold","-5","mA"
    "Permanent Fail","DFET","OFF Delay","5","s"
    "Permanent Fail","AFER","Threshold","100","-"
    "Permanent Fail","AFER","Delay Period","2","s"
    "Permanent Fail","AFER","Compare Period","5","s"
    "Permanent Fail","AFEC","Threshold","100","-"
    "Permanent Fail","AFEC","Delay Period","5","s"
    "Permanent Fail","AFE XREADY","Threshold","100","-"
    "Permanent Fail","AFE XREADY","Delay Period","5","s"
    "Permanent Fail","AFE External Override","Delay","5","s"
    "Permanent Fail","AFE SOV / AFE SUV","SOV and SUV Delay","50","hex"
    "Permanent Fail","AFE SOV","Threshold","4350","mV"
    "Permanent Fail","AFE SUV","Threshold","1750","mV"
    "Charge Algorithm","Temperature Ranges","Charge Inhibit/Suspend Low Temp","0","degC"
    "Charge Algorithm","Temperature Ranges","Precharge Temp","12","degC"
    "Charge Algorithm","Temperature Ranges","Charge Inhibit High Temp","45","degC"
    "Charge Algorithm","Temperature Ranges","Charge Suspsend High Temp","55","degC"
    "Charge Algorithm","Temperature Ranges","Hysteresis Temp","3","degC"
    "Charge Algorithm","Fast Charging","Voltage","3600","mV"
    "Charge Algorithm","Fast Charging","Current","5000","mA"
    "Charge Algorithm","Pre-Charging","Current","100","mA"
    "Charge Algorithm","Pre-Charging","Start Voltage","2000","mV"
    "Charge Algorithm","Pre-Charging","Recovery Voltage","2000","mV"
    "Charge Algorithm","Termination Config","Charge Term Taper Current","50","mA"
    "Charge Algorithm","Termination Config","Charge Term Voltage","75","mV"
    "Charge Algorithm","Cell Balancing Config","Cell Balance Threshold","3250","mV"
    "Charge Algorithm","Cell Balancing Config","Cell Balance Window","50","mV"
    "Charge Algorithm","Cell Balancing Config","Cell Balance Min","30","mV"
    "Charge Algorithm","Cell Balancing Config","Cell Balance Interval","20","s"
    "Fuel Gauging","Current Thresholds","Dsg Current Threshold","100","mA"
    "Fuel Gauging","Current Thresholds","Chg Current Threshold","50","mA"
    "Fuel Gauging","Current Thresholds","Quit Current","10","mA"
    "Fuel Gauging","Current Thresholds","Dsg Relax Time","60","s"
    "Fuel Gauging","Current Thresholds","Chg Relax Time","60","s"
    "Fuel Gauging","Design","Design Capacity mAh","9500","mAh"
    "Fuel Gauging","Design","Design Capacity cWh","6336","cWh"
    "Fuel Gauging","Design","Design Voltage","3700","mV"
    "Fuel Gauging","Cycle","Cycle Count Percentage","90","%"
    "Fuel Gauging","FD","Set % RSOC Threshold","0","%"
    "Fuel Gauging","FD","Clear % RSOC Threshold","5","%"
    "Fuel Gauging","FC","Set % RSOC Threshold","100","%"
    "Fuel Gauging","FC","Clear % RSOC Threshold","98","%"
    "Fuel Gauging","TD","Set % RSOC Threshold","6","%"
    "Fuel Gauging","TD","Clear % RSOC Threshold","8","%"
    "Fuel Gauging","TC","Set % RSOC Threshold","100","%"
    "Fuel Gauging","TC","Clear % RSOC Threshold","98","%"
    "Fuel Gauging","State","Cycle Count","3","-"
    "Fuel Gauging","State","Qmax Pack","9500","mAh"
    "Fuel Gauging","State","Learned Full Charge Capacity","8476","mAh"
    "Fuel Gauging","State","Dod at EDV2","9271","-"
    "Fuel Gauging","CEDV cfg","EMF","3743","-"
    "Fuel Gauging","CEDV cfg","C0","149","-"
    "Fuel Gauging","CEDV cfg","R0","867","-"
    "Fuel Gauging","CEDV cfg","T0","4030","-"
    "Fuel Gauging","CEDV cfg","R1","316","-"
    "Fuel Gauging","CEDV cfg","TC","9","-"
    "Fuel Gauging","CEDV cfg","C1","0","-"
    "Fuel Gauging","CEDV cfg","Age Factor","0","-"
    "Fuel Gauging","CEDV cfg","Fixed EDV 0","2300","-"
    "Fuel Gauging","CEDV cfg","EDV 0 Hold Time","15","s"
    "Fuel Gauging","CEDV cfg","Fixed EDV 1","2500","-"
    "Fuel Gauging","CEDV cfg","EDV 1 Hold Time","15","s"
    "Fuel Gauging","CEDV cfg","Fixed EDV 2","2750","-"
    "Fuel Gauging","CEDV cfg","EDV 2 Hold Time","15","s"
    "Fuel Gauging","CEDV cfg","Battery Low %","7.00","%"
    "Fuel Gauging","CEDV cfg","Min Delta V Filter","10","mV"
    "Fuel Gauging","CEDV cfg","FCC Learn Up","512","mAh"
    "Fuel Gauging","CEDV cfg","FCC Learn Down","256","mAh"
    "Fuel Gauging","CEDV cfg","Learning Low Temp","119","0.1degC"
    "Fuel Gauging","CEDV cfg","Requested Learning cycle count","20","num"
    "Fuel Gauging","CEDV cfg","OverLoad Current","5500","mA"
    "Fuel Gauging","CEDV cfg","Self Discharge Rate","20","0.01%/day"
    "Fuel Gauging","CEDV cfg","Electronics Load","0","3uA"
    "Fuel Gauging","CEDV cfg","Near Full","200","mAh"
    "Fuel Gauging","CEDV cfg","Reserve Capacity","300","mAh"
    "Power","Power","Valid Update Voltage","3300","mV"
    "Power","Shutdown","Shutdown Voltage","2000","mV"
    "Power","Shutdown","Shutdown Time","20","s"
    "Power","Shutdown","PF Shutdown Voltage","0","mV"
    "Power","Shutdown","PF Shutdown Time","10","s"
    "Power","Shutdown","Charger Present Threshold","3000","mV"
    "Power","Sleep","Sleep Current","10","mA"
    "Power","Sleep","Bus Timeout","30","s"
    "Power","Sleep","Voltage Time","30","s"
    "Power","Sleep","Current Time","30","s"
    "Power","Ship","FET Off Time","10","s"
    "Power","Ship","Delay","20","s"
    "Power","KEYIN","Time","2","s"
    "PF Status","Device Status Data","Safety Alert A","00","hex"
    "PF Status","Device Status Data","Safety Status A","00","hex"
    "PF Status","Device Status Data","Safety Alert B","00","hex"
    "PF Status","Device Status Data","Safety Status B","00","hex"
    "PF Status","Device Status Data","Safety Alert C","00","hex"
    "PF Status","Device Status Data","Safety Status C","00","hex"
    "PF Status","Device Status Data","PF Alert A","00","hex"
    "PF Status","Device Status Data","PF Status A","00","hex"
    "PF Status","Device Status Data","PF Alert B","00","hex"
    "PF Status","Device Status Data","PF Status B","00","hex"
    "PF Status","Device Status Data","PF Alert C","00","hex"
    "PF Status","Device Status Data","PF Status C","00","hex"
    "PF Status","Device Status Data","Fuse Flag","0000","hex"
    "PF Status","Device Status Data","Operation Status A","0000","hex"
    "PF Status","Device Status Data","Operation Status B","0000","hex"
    "PF Status","Device Status Data","Temp Range","00","hex"
    "PF Status","Device Status Data","Charging Status","00","hex"
    "PF Status","Device Status Data","Gauging Status","00","hex"
    "PF Status","Device Status Data","CEDV Status","00","hex"
    "PF Status","Device Voltage Data","Cell 1 Voltage","0","mV"
    "PF Status","Device Voltage Data","Cell 2 Voltage","0","mV"
    "PF Status","Device Voltage Data","Cell 3 Voltage","0","mV"
    "PF Status","Device Voltage Data","Cell 4 Voltage","0","mV"
    "PF Status","Device Voltage Data","Cell 5 Voltage","0","mV"
    "PF Status","Device Voltage Data","Cell 6 Voltage","0","mV"
    "PF Status","Device Voltage Data","Cell 7 Voltage","0","mV"
    "PF Status","Device Voltage Data","Cell 8 Voltage","0","mV"
    "PF Status","Device Voltage Data","Cell 9 Voltage","0","mV"
    "PF Status","Device Voltage Data","Cell 10 Voltage","0","mV"
    "PF Status","Device Voltage Data","Cell 11 Voltage","0","mV"
    "PF Status","Device Voltage Data","Cell 12 Voltage","0","mV"
    "PF Status","Device Voltage Data","Cell 13 Voltage","0","mV"
    "PF Status","Device Voltage Data","Cell 14 Voltage","0","mV"
    "PF Status","Device Voltage Data","Cell 15 Voltage","0","mV"
    "PF Status","Device Voltage Data","Battery Direct Voltage","0","mV"
    "PF Status","Device Current Data","Current","0","mA"
    "PF Status","Device Temperature Data","TS1 Temperature","-273.2","degC"
    "PF Status","Device Temperature Data","TS2 Temperature","-273.2","degC"
    "PF Status","Device Temperature Data","TS3 Temperature","-273.2","degC"
    "PF Status","AFE Regs","AFE SYS Stat","00","hex"
    "PF Status","AFE Regs","AFE Cell Balance1","00","hex"
    "PF Status","AFE Regs","AFE Cell Balance2","00","hex"
    "PF Status","AFE Regs","AFE Cell Balance3","00","hex"
    "PF Status","AFE Regs","AFE Sys Control1","00","hex"
    "PF Status","AFE Regs","AFE Sys Control2","00","hex"
    "PF Status","AFE Regs","AFE Protection1","00","hex"
    "PF Status","AFE Regs","AFE Protection2","00","hex"
    "PF Status","AFE Regs","AFE Protection3","00","hex"
    "PF Status","AFE Regs","AFE OV Trip","00","hex"
    "PF Status","AFE Regs","AFE UV Trip","00","hex"
    "Black Box","Safety Status","1st Status Status A","00","hex"
    "Black Box","Safety Status","1st Status Status B","00","hex"
    "Black Box","Safety Status","1st Safety Status C","00","hex"
    "Black Box","Safety Status","1st Time to Next Event","0","s"
    "Black Box","Safety Status","2nd Status Status A","00","hex"
    "Black Box","Safety Status","2nd Status Status B","00","hex"
    "Black Box","Safety Status","2nd Safety Status C","00","hex"
    "Black Box","Safety Status","2nd Time to Next Event","0","s"
    "Black Box","Safety Status","3rd Status Status A","00","hex"
    "Black Box","Safety Status","3rd Status Status B","00","hex"
    "Black Box","Safety Status","3rd Safety Status C","00","hex"
    "Black Box","Safety Status","3rd Time to Next Event","0","s"
    "Black Box","PF Status","1st PF Status A","00","hex"
    "Black Box","PF Status","1st PF Status B","00","hex"
    "Black Box","PF Status","1st PF Status C","00","hex"
    "Black Box","PF Status","1st Time to Next Event","0","s"
    "Black Box","PF Status","2nd PF Status A","00","hex"
    "Black Box","PF Status","2nd PF Status B","00","hex"
    "Black Box","PF Status","2nd PF Status C","00","hex"
    "Black Box","PF Status","2nd Time to Next Event","0","s"
    "Black Box","PF Status","3rd PF Status A","00","hex"
    "Black Box","PF Status","3rd PF Status B","00","hex"
    "Black Box","PF Status","3rd PF Status C","00","hex"
    "Black Box","PF Status","3rd Time to Next Event","0","s"
    "System Data","Manufacturer Data","Manufacturer Info A Length","32","-"
    "System Data","Manufacturer Data","Manufacturer Info Block A01","61","Hex"
    "System Data","Manufacturer Data","Manufacturer Info Block A02","62","Hex"
    "System Data","Manufacturer Data","Manufacturer Info Block A03","63","Hex"
    "System Data","Manufacturer Data","Manufacturer Info Block A04","64","Hex"
    "System Data","Manufacturer Data","Manufacturer Info Block A05","65","Hex"
    "System Data","Manufacturer Data","Manufacturer Info Block A06","66","Hex"
    "System Data","Manufacturer Data","Manufacturer Info Block A07","67","Hex"
    "System Data","Manufacturer Data","Manufacturer Info Block A08","68","Hex"
    "System Data","Manufacturer Data","Manufacturer Info Block A09","69","Hex"
    "System Data","Manufacturer Data","Manufacturer Info Block A10","6a","Hex"
    "System Data","Manufacturer Data","Manufacturer Info Block A11","6b","Hex"
    "System Data","Manufacturer Data","Manufacturer Info Block A12","6c","Hex"
    "System Data","Manufacturer Data","Manufacturer Info Block A13","6d","Hex"
    "System Data","Manufacturer Data","Manufacturer Info Block A14","6e","Hex"
    "System Data","Manufacturer Data","Manufacturer Info Block A15","6f","Hex"
    "System Data","Manufacturer Data","Manufacturer Info Block A16","70","Hex"
    "System Data","Manufacturer Data","Manufacturer Info Block A17","71","Hex"
    "System Data","Manufacturer Data","Manufacturer Info Block A18","72","Hex"
    "System Data","Manufacturer Data","Manufacturer Info Block A19","73","Hex"
    "System Data","Manufacturer Data","Manufacturer Info Block A20","74","Hex"
    "System Data","Manufacturer Data","Manufacturer Info Block A21","75","Hex"
    "System Data","Manufacturer Data","Manufacturer Info Block A22","76","Hex"
    "System Data","Manufacturer Data","Manufacturer Info Block A23","77","Hex"
    "System Data","Manufacturer Data","Manufacturer Info Block A24","7a","Hex"
    "System Data","Manufacturer Data","Manufacturer Info Block A25","78","Hex"
    "System Data","Manufacturer Data","Manufacturer Info Block A26","79","Hex"
    "System Data","Manufacturer Data","Manufacturer Info Block A27","30","Hex"
    "System Data","Manufacturer Data","Manufacturer Info Block A28","31","Hex"
    "System Data","Manufacturer Data","Manufacturer Info Block A29","32","Hex"
    "System Data","Manufacturer Data","Manufacturer Info Block A30","33","Hex"
    "System Data","Manufacturer Data","Manufacturer Info Block A31","34","Hex"
    "System Data","Manufacturer Data","Manufacturer Info Block A32","35","Hex"
    "SBS Configuration","Data","Remaining AH Cap. Alarm","300","mAh"
    "SBS Configuration","Data","Remaining WH Cap. Alarm","432","cWh"
    "SBS Configuration","Data","Remaining Time Alarm","10","min"
    "SBS Configuration","Data","Initial Battery Mode","0081","hex"
    "SBS Configuration","Data","Specification Information","0031","hex"
    "SBS Configuration","Data","Manufacture Date","1980-1-1","date"
    "SBS Configuration","Data","Serial Number","0001","hex"
    "SBS Configuration","Data","Manufacturer Name","Texas Instruments","-"
    "SBS Configuration","Data","Device Name","bq78350","-"
    "SBS Configuration","Data","Device Chemistry","LION","-"
    "LED Support","LED Config","LED Flash Period","512","488us"
    "LED Support","LED Config","LED Blink Period","1024","488us"
    "LED Support","LED Config","LED Delay","100","488us"
    "LED Support","LED Config","LED Hold Time","4","s"
    "LED Support","LED Config","LED Flash Alarm","10","%"
    "LED Support","LED Config","LED Thresh 1","0","%"
    "LED Support","LED Config","LED Thresh 2","20","%"
    "LED Support","LED Config","LED Thresh 3","40","%"
    "LED Support","LED Config","LED Thresh 4","60","%"
    "LED Support","LED Config","LED Thresh 5","80","%"
    "LED Support","LED Config","LCD Refresh Rate","35","Hz"
    "Lifetimes","Voltage","Cell 1 Max Voltage","3360","mV"
    "Lifetimes","Voltage","Cell 2 Max Voltage","3620","mV"
    "Lifetimes","Voltage","Cell 3 Max Voltage","3620","mV"
    "Lifetimes","Voltage","Cell 4 Max Voltage","3780","mV"
    "Lifetimes","Voltage","Cell 5 Max Voltage","3780","mV"
    "Lifetimes","Voltage","Cell 6 Max Voltage","3640","mV"
    "Lifetimes","Voltage","Cell 7 Max Voltage","3620","mV"
    "Lifetimes","Voltage","Cell 8 Max Voltage","3660","mV"
    "Lifetimes","Voltage","Cell 9 Max Voltage","0","mV"
    "Lifetimes","Voltage","Cell 10 Max Voltage","0","mV"
    "Lifetimes","Voltage","Cell 11 Max Voltage","0","mV"
    "Lifetimes","Voltage","Cell 12 Max Voltage","0","mV"
    "Lifetimes","Voltage","Cell 13 Max Voltage","0","mV"
    "Lifetimes","Voltage","Cell 14 Max Voltage","0","mV"
    "Lifetimes","Voltage","Cell 15 Max Voltage","0","mV"
    "Lifetimes","Voltage","Cell 1 Min Voltage","2160","mV"
    "Lifetimes","Voltage","Cell 2 Min Voltage","3280","mV"
    "Lifetimes","Voltage","Cell 3 Min Voltage","3280","mV"
    "Lifetimes","Voltage","Cell 4 Min Voltage","3280","mV"
    "Lifetimes","Voltage","Cell 5 Min Voltage","3280","mV"
    "Lifetimes","Voltage","Cell 6 Min Voltage","3280","mV"
    "Lifetimes","Voltage","Cell 7 Min Voltage","3280","mV"
    "Lifetimes","Voltage","Cell 8 Min Voltage","3260","mV"
    "Lifetimes","Voltage","Cell 9 Min Voltage","5100","mV"
    "Lifetimes","Voltage","Cell 10 Min Voltage","5100","mV"
    "Lifetimes","Voltage","Cell 11 Min Voltage","5100","mV"
    "Lifetimes","Voltage","Cell 12 Min Voltage","5100","mV"
    "Lifetimes","Voltage","Cell 13 Min Voltage","5100","mV"
    "Lifetimes","Voltage","Cell 14 Min Voltage","5100","mV"
    "Lifetimes","Voltage","Cell 15 Min Voltage","5100","mV"
    "Lifetimes","Voltage","Max Delta Cell Voltage","1420","mV"
    "Lifetimes","Current","Max Charge Current","2451","mA"
    "Lifetimes","Current","Max Discharge Current","-1941","mA"
    "Lifetimes","Current","Max Avg Dsg Current","-1888","mA"
    "Lifetimes","Current","Max Avg Dsg Power","-5175","cW"
    "Lifetimes","Temperature","Max Temp Cell","40","degC"
    "Lifetimes","Temperature","Min Temp Cell","17","degC"
    "Lifetimes","Temperature","Max Delta Cell Temp","23","degC"
    "Lifetimes","Safety Events","No Of COV Events","61","events"
    "Lifetimes","Safety Events","Last COV Event","3","cycles"
    "Lifetimes","Safety Events","No Of CUV Events","7","events"
    "Lifetimes","Safety Events","Last CUV Event","3","cycles"
    "Lifetimes","Safety Events","No Of OCD Events","0","events"
    "Lifetimes","Safety Events","Last OCD Event","0","cycles"
    "Lifetimes","Safety Events","No Of OCC Events","0","events"
    "Lifetimes","Safety Events","Last OCC Event","0","cycles"
    "Lifetimes","Safety Events","No Of AOLD Events","0","events"
    "Lifetimes","Safety Events","Last AOLD Event","0","cycles"
    "Lifetimes","Safety Events","No Of ASCD Events","0","events"
    "Lifetimes","Safety Events","Last ASCD Event","0","cycles"
    "Lifetimes","Safety Events","No Of OTC Events","0","events"
    "Lifetimes","Safety Events","Last OTC Event","0","cycles"
    "Lifetimes","Safety Events","No Of OTD Events","0","events"
    "Lifetimes","Safety Events","Last OTD Event","0","cycles"
    "Lifetimes","Charging Events","No Valid Charge Term","11","events"
    "Lifetimes","Charging Events","Last Valid Charge Term","2","cycles"
    "Lifetimes","Gauging Events","No of FCC Updates","4","events"
    "Lifetimes","Gauging Events","Last FCC Update","3","cycles"
    "Lifetimes","Power Events","No Of Shutdowns","21","events"
    "Lifetimes","Cell Balancing","Cb Time Cell 1","0","h"
    "Lifetimes","Cell Balancing","Cb Time Cell 2","58","h"
    "Lifetimes","Cell Balancing","Cb Time Cell 3","58","h"
    "Lifetimes","Cell Balancing","Cb Time Cell 4","58","h"
    "Lifetimes","Cell Balancing","Cb Time Cell 5","60","h"
    "Lifetimes","Cell Balancing","Cb Time Cell 6","60","h"
    "Lifetimes","Cell Balancing","Cb Time Cell 7","58","h"
    "Lifetimes","Cell Balancing","Cb Time Cell 8","74","h"
    "Lifetimes","Cell Balancing","Cb Time Cell 9","0","h"
    "Lifetimes","Cell Balancing","Cb Time Cell 10","0","h"
    "Lifetimes","Cell Balancing","Cb Time Cell 11","0","h"
    "Lifetimes","Cell Balancing","Cb Time Cell 12","0","h"
    "Lifetimes","Cell Balancing","Cb Time Cell 13","0","h"
    "Lifetimes","Cell Balancing","Cb Time Cell 14","0","h"
    "Lifetimes","Cell Balancing","Cb Time Cell 15","0","h"
    "Lifetimes","Time","Total Fw Runtime","836","h"
    "Lifetimes","Time","Time Spent In UT","0","h"
    "Lifetimes","Time","Time Spent In LT","0","h"
    "Lifetimes","Time","Time Spent In ST","836","h"
    "Lifetimes","Time","Time Spent In HT","0","h"
    "Lifetimes","Time","Time Spent In OT","0","h"
    "Lifetimes","Time","Time Since Last Charge","0","h"
    "GPIO","GPIO Config","GPIO Configuration","80","hex"
    "GPIO","GPIO Config","GPIO Ouput Enable","80","hex"
    "GPIO","GPIO Config","GPIO Default Ouput Enable","80","hex"
    "GPIO","GPIO Config","GPIO Type","40","hex"
    

    2514.log9.log

  • Hi Brian,
    Thanks for the log. As you know it shows balance for some time during charge with voltage increase and a large delta. Then balance stops after many intervals.
    Apparently the behavior encountered is described in the TRM section 7.1 for the balance threshold adjustment , "or the highest cell exceeds the cell balance threshold by the cell balance window."
    During balancing cell 5 voltage is jumping around, in the log samples shortly before it stops 3307 to 3351. It is expected the balance threshold would have adjusted up from the starting 3250 to 3300 to 3350 mV as the high cell voltage rose. When the high cell voltage exceeds the threshold and the threshold adjusts to 3400mV, balance will stop. The battery continues to charge but never to the voltage which re-starts balancing.
    Check the interconnect resistance at cell 5 (cell 4), it seems the balancing current may be altering the cell voltage.