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BQ40Z50-R1: am testing single battery testing of li-ione, when am started for learning cycleprocess am getting the charging issue,it does not charging,current is not limited. please give me the proper settings of voltages and current.am attached a advance

Part Number: BQ40Z50-R1
Other Parts Discussed in Thread: BQ40Z50, , BQ40Z50-R2, BQSTUDIO
  • Vish

       From your next post, I see you already know to use FET control command to turn on the FET for charging. I think this is probably the reason why you do not see charge current here.

      Please also be noted that your Set Threshold for FD is way to high, please set this low to below or equal to 3000mV, this is the typical setting for this parameter

  • Thanks for the reply.i will check it.

  • I was checking but its not working,please send a proper settings for charging and discharging.i was attached a gg files for your reference.

  • Hi Vish

        The latest version for bq40z50 is R3.08, I get charging and discharging enabled base on default setting for V3.08. Please give me your email so that I can send the srec and gg file to you. But you still need to configure other parameters per your customer requirement and battery specs, the battery modeling parameters should also be configured appropriately by selecting proper chemical ID and doing the learning cycle.please refer the bq40z50TRM for further detailed steps

  • Thanks for your reply steven, here is my email id. for my testing purpose i using only single cell icr18650-26f, after successful learning cycle of this single cell,later am testing 2s-2p configaration cell.

    part number=bq40z50-r1

    email id=vishwa.aradhya@cedlabs.in

  • what is pre-charging in this section,i should use pchg-fet in gauging,it is necessary, i am bit confusing with charging fet  and pre charging fet section during settings.

  • The gauge enters PRECHARGE mode if,
    1. Min cell voltage1..4 < Precharge Start Voltage OR
    2. Max cell voltage1..4 < Charging Voltage Low – Charging Voltage Hysteresis and not in CHARGE
    mode
    Depending on the FET Options[PCHG_COMM] settings, the external precharge FET or CHG FET can be
    used in PRECHARGE mode. Setting Precharge Start Voltage and Charging Voltage Low = 0 mV
    disables the precharge function.


    [PCHG_COMM] = 0                          [PCHG_COMM] = 1
    FET USED: external                         precharge FET FET USED: CHG FET


    The bq40z50-R2 device also supports 0-V charging using either an external precharge FET or CHG FET.
    If [PCHG_COMM] = 1, the gauge enables the hardware 0-V charging circuit automatically when the
    battery stack voltage is below the minimum operation voltage of the device (see the bq40z50-R2 1-Series
    to 4-Series Li-Ion Battery Pack Manager data sheet [SLUSCS4] for bq40z50-R2 electrical specifications).

  • hello steven

    what u given srec file i uploded to bqstudio,it is started charging,am started the learnig cycle,the first step of discharging takes 1 hour and reset bit and rdis bits are set and again i started the next step of learning cycle means charging of cells to full it taking 4-5 hours for charging i think this process is reversed,as i read TRM charging takes 2 hours and discharging takes 5 hours.what i gone wrong please suggest me.

    REGARDS

    Vishwa

  • ra tables uptading in charging mode,it is updated in discharge mode am i right?

  • Is thier any options for setting capacity ratings for charging and discharging in bqstudio.

  • this is what happening in charging mode,ra tables are updating during charge mode.

  • Hi, Vish

        Before you run the learning cycle, you still need to identify the chemical ID of the cells and then download the chem ID data to the target device. Otherwise, the learning cycle will not yield expected result. For details on how to configure the dataflash, please refer to below documents:

    www.ti.com/lit/an/slua334b/slua334b.pdf

     

  • Vish

        Please log the registers data during your test and dataflash autoexport file, you can get this auto saved gg file at regular interval by click the AutoExport Buttong.

        The log interval can be set by clicking windows->preference

  • ok steave, am using SAMSUNG ICR18650-26J Battery pack but am selecting SDI ICR18650-26A (2600mah) it is the main fault am not able to get a proper learning cycle,(charging and discharging).PLEASE suggest me.

  • Hi, Vish

        Yes, you need to make sure the chem ID matches with the cells attached to the gauge, otherwise, the result will be bad

  • vishwaradhya G said:

    hello steven

    I was fixed the FD voltage to 3000 and set % rsoc to 0% but initial discharge comes to 3000 volts vok and rdis bits are not cleard during initial discharge.why it is happend.

    REGARDS

    Vishwa

  • Hi, Vish

        It seems that you are doing learning cycle, right? But in the first place, have the gauge configured with correct chemical ID instead of default one?

        After the correct chemical ID has been written to the gauge. then you can do learning cycle. according the steps described in the document I attached previously:

    1. Set an initial guess of Qmax (as found from previous IT tests or by discharging the battery at a C/20
    rate).
    2. Enable IT (command 0021).
    3. Charge the pack to full.
    4. Let it relax for 2 hours.
    5. Discharge the pack to minimal device acceptable voltage (also set as Term Voltage flash constant) at
    a typical low rate (usually C/5) of your target application. The exact rate is noncritical. MaxError will
    change to 5%.
    6. Let it relax for 5 hours. Qmax will update, MaxError will change to 1%, and the Update Status will
    change to 6%.
    7. Repeat the foregoing steps 4 through 6 one more time to achieve the best resistance accuracy. (The
    accuracy after the first cycle can be affected by the inaccurate initial guess of the Qmax value.)
    8. If the Operation Status bit R_DIS is set during this test, the Qmax initial guess was not accurate
    enough and so learning needs to be made using the previous procedure or after reloading the default
    settings and using the newly learned Qmax value as an initial guess.

        At the end of step 4, you need to make sure that the VOK and RDIS are cleared. if these 2 bits are cleared at this moment, then typically you wont see them set at end of discharge at step 5.

        if these bits remains set when you make sure all above steps are done correctly, please send out the log file of both registers and dataflash for further analysis