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BQ27520-G4: Wait_ID flag

Part Number: BQ27520-G4
Other Parts Discussed in Thread: GPCCHEM

Hello, we are using a BQ27520-G4.  

When a battery is inserted and charging, reading back the flags we see the following are set OCV_GOOD, BAT_DET, CHG, and WAIT_ID.  

However, after a few minutes WAIT_ID is stays true. 

Does anyone know how WAIT_ID is set or how it works?  

The ref manual does not have much information on WAIT_ID.


  • Ryan,

    Did you identify your chem id and run a learning cycle on your pack? From the TRM description, the gauge is waiting to identify which resistance table to use. You have to program the correct chem id and run learning cycle , and when you have update status changed to 02, copy the resistance table that learnt into all the other resistance tables.

  • Onyx,

    Based on SLUA616

    Battery Characteristic Data is generated with an EVM - VIA SLUA544
    - Chem ID
    - RA Tables
    Board Characteristics - VIA SLUA449
    - CC Offset
    - Board Offset
    - Voltage Calibration
    - Temperature Calibration
    - Pack Current Calibration

    Steps --
    Take the DFI - created with EVM VIA SLUA544
    Modify the calibration parameters from 20-30 sample boards. Average and extract for production units.

    On the production unit that has been loaded with the Golden DFI (above). We are not using the automatic BAT INSERT detection. We boot up, then send the BAT_INSERT command 0x00 0x0D 0x00.
    -Is this the correct procedure?
    -Do we need to do anything else on bootup to the production unit?
    -How does the WAIT_ID flag play into this?
    -Does the WAIT_ID flag indicate there was something wrong with our golden image?

  • Ryan

    Can you share a log and gg files? Does this issue occur on multiple packs or just one?



  • Hi Ryan,
    I double checked the operation of the wait_id flag.

    The wait_d will clear during a discharge when DoD crosses an Ra grid point and RUP_DIS is clear. It rarely takes more than about 10% discharge to clear. There is no requirement for WAIT_ID to clear for the system to use the battery. It is more an indication of the gauge accuracy. Clearly there will be the potential for inaccuracy until the battery has been identified. Also, a Qmax update can cause WAIT_ID to clear as well.

  • Hello Onyx,

    Can you have a look at a log file, however we would like to provide it without posting it on the forum.

    How can I get it to you.

    Thanks, Ryan

  • hi Ryan,
    What's the current issue?
    I have sent you a friend request. This will enable you email the file to me.
  • We are going through a learning cycle following a document named LearningCycleOverview.pdf

    All the steps were completed: Discharge, Relax 5h, then the battery is charged to full via C/5 and we see VOK and FC are set.

    During the relaxation more than 2 hours has elapsed. VOK and RUP_DIS are clear, and FC is set.

    Update Status is still 0x00.

    We are using the pack to power REGIN.
  • Ryan
    what chem id are you using? Did you use gpcchem to identify the correct chem id for your battery? Did you program the chem id on your gauge?

  • Yes the correct CHEM_ID is programmed.