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BQ34Z100-G1: End Of Charge and Charge Termination

REDDY
Intellectual 465 points
Part Number: BQ34Z100-G1

Hi,

Battery Specs

  • Cell Chemistry: NiMH
  • Series: BK220SCHU
  • Nominal Voltage:1.2 V
  • Rating Capacity: 2200 mAh
  • Charging: -deltaV per cell is 10mV (cell)
  • Rapid Charge temperature: 0-60 degree C
  • Discharge temperature: 0-75 degree C
  • ChemID: 6112 (TI suggested)
  • Battery pack configuration: 10S

During charge phase, as When RMFCC is '0' (Not set) in data memory, i expect RemainingCapoacity is not set equal to FullChargeCapacity, and when the valid NegativeDeltaVoltage occurs, the CHG bit has to move from 1 to 0(Bit HIGH to LOW in Flags(). But I'm not seeing the CHG bit is moving from HIGH to LOW and if this happens i can't terminate the charger using our micro. Because I'm using Flag() CHG to terminate our charger.

I attach the data memory (BEFORE: 1Prova 3.1_RMFCC_Disable_scarica e carica.gg and AFTER: 77Prova 3.1_RMFCC_Disable_scarica e carica.gg ) and log file (Prova 3.1_RMFCC_Disable_scarica e carica), Please go through it.

77Prova 3.1_RMFCC_Disable_scarica e carica.gg.csv

1Prova 3.1_RMFCC_Disable_scarica e carica.gg.csv

Prova 3.1_RMFCC_Disable_scarica e carica.log

Thanks in advance!!

Regards,

Reddy

  • 0
    TI__Guru 52115 points
    I would need some time to check your files and provide some feedback later.
    Andy 
  • 0 in reply to Andy Liu (BMS)
    Intellectual 465 points

    I look forward!!

    Regards,

    Reddy

  • 0 in reply to REDDY
    TI__Guru 52115 points

    I was only able to take a quick look at your gg file today.  The NiMH Charge configurations seem okay to me. Allow me to spend more time on this issue tomorrow and then get back to you.

    Andy

  • 0 in reply to Andy Liu (BMS)
    TI__Guru 52115 points
    See my comments below.
    I see the following settings in their gg file. These settings seem to be per battery cell.
    "Configuration","Charge Termination","NiMH Cell Negative Delta Volt","10","mVolt"
    "Configuration","Charge Termination","NiMH Cell Neg Delta Qual Volt","1400","mVolt"
    Here is what is mentioned about the negative delta voltage in the TRM.  The NiMH charge termination parameter settings should be at that pack level.
    For negative delta voltage, the bq34z100-G1 detects a charge termination when the pack voltage drops during charging by Cell Negative Delta Volt for a period of Cell Negative Delta Time during which time Voltage() must be greater than Cell Negative Qual Volt.
    Also, take a look at the following thread, which is a similar issue.
    Andy
  • 0 in reply to Andy Liu (BMS)
    TI__Intellectual 1300 points

    Thanks for your feedback.

     

    Please find here the feedback :

     

    Andy comment related to Charge termination parameters, I accept it. But my discussion is related to RMFCC and CHG flag.

     

    As you and Andy said the parameters are related to pack level, I accept it.

     

     

    Basically in the TRM, the entire explanation is considered for Lithium batteries

    Consider the Default value in the Table 7-1. Data summary;

    NiMH Cell Negative Delta Volt is 17mV per cell not pack level

    NiMH Cell Neg Delta Qual Volt is 4200mV per cell not the pack level

     

    "Configuration","Charge Termination","NiMH Cell Negative Delta Volt","10","mVolt"

    "Configuration","Charge Termination","NiMH Cell Neg Delta Qual Volt","1400","mVolt"

     

    My question is related to RMFCC and CHG flag during charge Termination in TI community is:

     

    As stated in In TRM pagNo: 30 (SLUUBW5–July 2018)

    When either condition occurs, the Flags()[CHG] bit is cleared. Also, if the [RMFCC] bit of Pack Configuration is set, and RemainingCapacity() is set equal to FullChargeCapacity().

     

    Basically we did two tests,

    1. RMFCC bit of pack configuration is set
    2. RMFCC bit of pack configuration is not set

    The result I excepted of those two tests is;

    If valid charge termination occurs, the Falg() [CHG] is cleared, also if the [RMFCC]  bit of pack configuration is set (In data memory -> Pack Configuration RMFCC = HIGH) then RemainingCapacity() = FullChargeCapacity().

     

    Whereas another condition,  If valid charge termination occurs, the Falg() [CHG] is cleared, also if the [RMFCC]  bit of pack configuration is not set (In data memory -> Pack Configuration RMFCC = low) then RemainingCapacity() is not equal to FullChargeCapacity().

     

    In the second test, as you see above, I configured [RMFCC] bit as LOW to expect the RemainingCapacity() is not equal to FullChargeCapacity(),  but here in this test, I’m not seeing the Flag CHG bit is clearing at the valid charge termination.

     

    For reference here is the link of the discussion which we made in community and you can review the log attached over there.

    https://e2e.ti.com/support/power-management/f/196/p/920207/3414947#3414947

     

     

    I look forward to hearing from you

  • 0 in reply to Manuel Infante
    TI__Genius 12215 points

    Hi,

        Per your description above, I understand you need some resorts to turn off the charger when the full charge condition is detected, if this is the case can you use FC bit in the same register for charge termination?

        For RM and FCC synchronizing, looks like even this bit is not set, there is still a mechanism to synchronize the RM and FCC to DOD, which is 0 at this condition, I need to check this with internal team, but does this matter in your application or you just want to know the reason of this phenomenon?