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BQ34Z100: Learning Cycle Procedure

nima shirazi
Prodigy 50 points
Part Number: BQ34Z100
Other Parts Discussed in Thread: GPCCHEM

Hello, I'm trying to follow the procedure outlined here: https://www.ti.com/lit/ug/sluubw5a/sluubw5a.pdf

I noticed that my cycle count is 19 and I had previously set the IT_Enable command. I want to undo this before performing a fresh learning cycle. How should I go about doing this if I want to keep my configurations?

Also, I am working with Panasonic HHR-210AAB (2000mAH) batteries (for which there is no existing chem ID). Using the GPCCHEM tool multiple times, I got an ID for Panasonic BK370AH (3500mAH). Will this be an issue?

Thanks, 

Nima 

  • 0
    TI__Mastermind 25021 points

    Hello Nima, 

    To reset the cycle count, you should first disable the IT algorithm, then you should be able to change the cycle count in the Data memory. 

    Can you please attach the GPCCHEM report you got from using the GPCCHEM tool? 

    Regards, 

    Jonny. 

  • 0 in reply to Jonny
    Prodigy 50 points

    Hey Jonny,

    Thanks for the prompt response. I dont think I can disable the IT algorithm by pressing IT_Enable again. "This is different from earlier gauges in that IT enable command can be toggled on and off. In earlier gauges, once IT is enabled, it can never be disabled via command."

    Should I reprogram the IC?

    Here is the report and the logged data used for the report:

    Here is also a previous thread in which i discussed this issue with a TI member.

    config-report (3).zip3755.config.zip

  • 0 in reply to nima shirazi
    Prodigy 50 points

    Also, the procedure here mentions two things that I'm not entirely sure about:

    a. Ensure charger cutoff upon charge completion: Most users do not have a battery cycling automation setup, so a bench power supply is used to change a battery overnight. This is not recommended. The system does follow a CC/CV profile, but there is no cutoff. Therefore, when the gauge recognizes a full charge and tries to take an OCV measurement, it actually measures the supply voltage and disrupts the system.

    b. CC/CV charge profile: In line with the above, ensure that a CC/CV profile charger with reasonable values is used: C/2 fast charge rate, C/100 to C/10 taper current.

    My questions are:

    1. do we have to include taper current termination or can we just stop charging from the Fast charge state? Note that there is no mention of taper charging here: Charge Battery to Full

    • A typical C/2 charge rate is recommended; however, the charge rate is of no consequence.

    • Make sure IT is already enabled at this point before the start of charge (the [Gauge_EN] bit in the manufacturing status() register should be set). • At the start of charge, the [VOK] bit in the IT status () register sets automatically.

    • At the end of charge the [FC] bit in the Battery Status () register should be set automatically. If it did not set then a full charge was not properly detected and the learning cycle fails. Correct either the charging conditions or the relevant dataflash settings to ensure the [FC] bit gets set and try again from the beginning.

    2. how much time do i have after the FC flag is set to stop charging before an OCV measurement is made

  • 0 in reply to nima shirazi
    TI__Mastermind 25021 points

    Hello Nima, 

    You can refer to this E2E thread for disabling IT_ENABLE. 

    I recommend using the 6112 ChemID that the GPCCHEM report generated. 

    1. It is recommended to include a taper current termination. Please see the following screenshot taken from the BQ34Z100-G1 Technical Reference Manual. 
    2. Please refer to section 3.7 Charging and Charge Termination Indication from the BQ34Z100-G1 Technical Reference Manual. 
  • 0 in reply to Jonny
    Prodigy 50 points

    Hey again, 

    thank you for referencing the E2E thread and the chem ID recommendation, however, section 3.7 of the reference manual only talks in detail about detecting the full charge status and not how much time we get to disable charging; im referring to: "Therefore, when the gauge recognizes a full charge and tries to take an OCV measurement, it actually measures the supply voltage and disrupts the system."