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BQ40Z80: BQ40Z80 DSG & CHG not working

Part Number: BQ40Z80
Other Parts Discussed in Thread: BQSTUDIO

The below screenshot shows the schematics of the BMS circuit. We are getting I2C communication and is working properly and also able to read the battery & cell voltage. Tested the safety features and no issues found. But unable to enable the two MOSFETs charging & discharging. We wrote the below mentioned commands in the reference manual but not able to turn ON. Initially we had shorted the PACK & battery to turn ON the BMS

  • Hi Ancy,

    I would like to narrow down if this is a hardware related issue or an issue with how the gauge is interpreting the command being sent. Can you try to use BQStudio in order to send the CHG_FET_TOGGLE and DSG_FET_TOGGLE commands via the commands window and see if that works? If it does then we know it is simply an issue with how the gauge is reading the command being sent when not from the commands window.

    If not, we can dig deeper to try to find the root cause.

    Best Regards,