This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

BQ20Z60-R1: BQ20Z60-R1

Part Number: BQ20Z60-R1
Other Parts Discussed in Thread: BQ20Z65-R1,

Problem Description:

Our Pump alerts when charging. We found that a control panel in Pump can't capture the feedback signal from battery power. By restart, the alert was disappeared, and never happened again.


By reading the part instruction of BQ20Z60, we have some questions listed as below:

  1. What are the specific meanings of ICC bits? Why are some states "1" and some "0"?

  2. What function does ICC bits control the battery? Is ICC bits related to signal transmission?

  3. Is the status of ICC bits related to signal transmission?

  4. The specification of BQ20Z60 states that the ICC is read-only. When the ICC bit is initially 1, why can we modify the ICC bit to 0 and read the data to 0?

  • Hi,

    The ICC bit is just an indicator to the host if the internal charge controller is supported or not

    It should be set to 1

    The status is not related to signal tranmission or comms from the gauge.

    The TRM advises you to keep it as read only and not change it. Please keep it at 1.

  • Thanks for feedback.

    Futher question:

    If the ICC bit should be set to 1, and read-only specified in specification, why it wasn't blocked, but could be changed by user?

    What about the factory setting? Why the ICC bit in some IC we received are 1, some we received are 0? What maybe trigger the ICC bit change?

    Best regards,


  • Hi Rainy,

    It's not read only as we want it to be customer configurable. It's default set to 1, if it changes, it will only be because that was updated by the user.

  • Hi Batt,

    ICC bit should be read only specified in specification as below. Why it is not read ony you said?

    Futher question regarding Bcast bit:

    Problem description:

    Our pump alarm when charging/discharging. (By analysis we found that a control board in Pump failed to communicate through I2C and TIBQ20Z60 in batteries, and I2C of our host failed to write, always busy.)

    After restarting once, all the phenomena disappeared, many tests were all right, 10 out of 150 devices cannot work.

    a. By TIBQ20Z60 specification, the default of BCAST bit should be 0, but all the parts we received in battery is set to 1. Is there any problem?

    b. In the chip Configuration, the Bcast bit is set to 1 actually. By reading user manual, if this bit is 1, will BQ20Z60 regularly send messages to bus as the I2C master role?

    Because the program of our mainboard always thinks that the chip on our motherboard is I2C master. If the battery wants to send messages as master at this time, will it possibly cause two master conflicts?

    c. In addition, we can't imagine that there are other situations that will cause I2C communication to fail. Do you have any experience with similar problems?

    Thank you


  • Hi Batt,

    I am not sure if you could see the printscreen in my last mail.

    So for your easy understanding  I'd like tell you that

    - For ICC topic, pls refer to Clause A.4 in page 67 of

    - For BCAST topic, pls refer to the last part in page 174 of Technical Reference bq20z60-R1/bq20z65-R1

    Best regards,


  • Hi Rainy,

    We have not had issues with the IC. But you will have a problem when there are 2 ICs trying to master the same bus. With BCAST the gauge will try to broadcast as master. Unless device arbitration is used, the bus can hang up.