BQ34Z100-G1: SOC is not accurate

Part Number: BQ34Z100-G1
Other Parts Discussed in Thread: BQSTUDIO

I have completed the learning cycle and enabled Impedance Track™. It is found that the SOC curve is not smooth. What could be the reason for this? Is it related to the max DOD error reported by the GPC tool?

2148.log.xlsx

  • Hi Mengxiao,

    Did you set the battery characteristic parameters correctly? And the update status change as expected? You can refer to AN (SLUA903) to check if you have done the right learning cycle process. You can also refer to AN (SLVA725A) to check if you follow the right process to match the CHEMID.

    Please provide GPC file that you uploaded and the report from GPC tool, battery characteristic information stated in datasheet, the gg file and the log file, we need to have a look.

    SIncerely,

    Jayden

  • Hi Jayden,

    1.The following is the modified configuration before learning. We scaled the battery current by 4 times, where Res Current and Qmax Max Delta% keep the firmware default values. Zooming Res Current will fail to update Ra Table, and the update status will always stay at 0x05. The unit of Qmax Max Delta% is not mA and should not be scaled.

    (1) Basic configuration

    CLASS

    SUBCLASS

    NAME

    DEFAULT

    STANDARD

    SCALE 4X

    Configuration

    Safety

    OT Chg

    550

    650

    -

    Configuration

    Safety

    OT Chg Time

    2

    10

    -

    Configuration

    Safety

    OT Chg Recovery

    500

    600

    -

    Configuration

    Safety

    OT Dsg

    600

    800

    -

    Configuration

    Safety

    OT Dsg Time

    2

    10

    -

    Configuration

    Safety

    OT Dsg Recovery

    550

    750

    -

    Configuration

    Charge Termination

    Taper Current

    100

    100

    25

    Configuration

    Charge Termination

    Cell Taper Voltage

    100

    100

    -

    Configuration

    Charge Termination

    TCA Set %

    99

    -1

    -

    Configuration

    Charge Termination

    TCA Clear %

    95

    98

    -

    Configuration

    Charge Termination

    FC Set %

    100

    -1

    -

    Configuration

    Charge Termination

    FC Clear %

    98

    98

    -

    Configuration

    Data

    Cycle Count

    0

    0

    -

    Configuration

    Data

    CC Threshold

    900

    9315

    2329

    Configuration

    Data

    Design Capacity

    1000

    10350

    2588

    Configuration

    Data

    Design Energy

    5400

    3726

    932

    Configuration

    Data

    Design Energy Scale

    1

    10

    -

    Configuration

    Registers

    Pack Configuration

    41d9

    2999

    -

    Configuration

    Registers

    Alert Configuration

    0

    0

    -

    Configuration

    Registers

    Number of series cell

    1

    7,12

    -

    Configuration

    Power

    Sleep Current

    10

    10

    3

    Configuration

    Power

    FS Wait

    0

    255

    -

    Gas Gauging

    IT Cfg

    Cell Terminate Voltage

    3000

    2500

    -

    Gas Gauging

    Current Thresholds

    Dsg Current Threshold

    60

    30

    8

    Gas Gauging

    Current Thresholds

    Chg Current Threshold

    75

    50

    13

    Gas Gauging

    Current Thresholds

    Quit Current

    40

    25

    6

    Gas Gauging

    State

    Qmax Cell 0

    1000

    10350

    2588

    Gas Gauging

    State

    Cycle Count

    0

    0

    -

    Calibration

    Current

    Deadband

    5

    20

    5

    (2) Scaling configuration

    CLASS

    SUBCLASS

    NAME

    DEFAULT

    STANDARD

    SCALE 4X

    Configuration

    Charge Termination

    Taper Current

    100

    100

    25

    Configuration

    Charge Termination

    Min Taper Capacity

    25

    25

    6

    Configuration

    Charge Termination

    NiMH Hold Off Current

    240

    240

    60

    Configuration

    Data

    CC Threshold

    900

    9315

    2329

    Configuration

    Data

    Design Capacity

    1000

    10350

    2588

    Configuration

    Data

    Design Energy

    5400

    3726

    932

    Configuration

    Data

    SOH Load I

    -400

    -400

    -100

    Configuration

    Discharge

    SOC1 Set Threshold

    150

    150

    38

    Configuration

    Discharge

    SOC1 Clear Threshold

    175

    175

    44

    Configuration

    Discharge

    SOCF Set Threshold

    75

    75

    19

    Configuration

    Discharge

    SOCF Clear Threshold

    100

    100

    25

    Configuration

    Lifetime Resolution

    LT Cur Res

    100

    100

    25

    Configuration

    Power

    Sleep Current

    10

    10

    3

    Gas Gauging

    IT Cfg

    Res Current

    10

     

     

    Gas Gauging

    IT Cfg

    User Rate-mA

    0

    0

    0

    Gas Gauging

    IT Cfg

    User Rate-Pwr

    0

    0

    0

    Gas Gauging

    IT Cfg

    Reserve Cap-mAh

    0

    0

    0

    Gas Gauging

    IT Cfg

    Reserve Energy

    0

    0

    0

    Gas Gauging

    IT Cfg

    Qmax Max Delta %

    10

     

     

    Gas Gauging

    Current Thresholds

    Dsg Current Threshold

    60

    30

    8

    Gas Gauging

    Current Thresholds

    Chg Current Threshold

    75

    50

    13

    Gas Gauging

    Current Thresholds

    Quit Current

    40

    25

    6

    Gas Gauging

    State

    Qmax Cell 0

    1000

    10350

    2588

    Gas Gauging

    State

    Avg I Last Run

    -299

    -299

    -75

    Gas Gauging

    State

    Avg P Last Run

    -1131

    -1131

    -283

    Calibration

    Current

    Deadband

    5

    20

    5

    2.No abnormality is found in the update status, and it will be updated to 0x06 in the end. The battery pack is SANYO NCR18650GA 7S3P. The chemical ID of the battery already exists, and 0x1580 is selected. GPC tools have also been used for analysis. Below I provide uploaded GPC files and reports of GPC tools, battery data sheets, gg files after learning, and log files during learning.

    20201106_sacle_4.zip

    3. The version of bqStudio I am using is 1.3.101_Build1, and the software is the latest. After the software executes the write chemical ID command, it prompts that the bqz file is old. Will it write wrong chemical ID data? Although I found that the data on the Ra Table has been updated.

    SIncerely,

    Mengxiao

  • Hi Mengxiao,

    We are looking into this you can expect a responce early next week.

    BR,

  • Hello, many days have passed, please let me know the progress.

  • Hi Mengxiao,

    Please check if the smooth bit in Pack Configuration C is set. If not, please set it and test again.

    Sincerely,

    Jayden

  • Hi Jayden,

    SMOOTH has been set, and the value of Pack Configuration C is 0x37.This should be the default value.

    Sincerely,

    Mengxiao

  • Hello Mengxiao,

    Your temperature increases to 84degC during the log shared, is the thermistor placed correctly on the battery? This is almost the max operating condition of the gauge, does the gauge report more accurate SOC at lower temperatures / lower discharges?

    You can also edit the load mode/ load select to more closely align with your system.

    Sincerely,

    Wyatt Keller

  • Hello Wyatt Keller,

    There is not much difference in temperature. Can I use the Gauging Parameter Calculator (GPC) Tool at such high temperatures?

    Sincerely,

    Mengxiao

  • Hello Mengxiao,

    I would check your thermistor settings or position because the reported temperature in the log is very high and can cause to gauging inaccuracies.

    Sincerely,

    Wyatt Keller