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BQ25619EVM: Unable to write the parameters to BQ25619 via EV2400

Part Number: BQ25619EVM
Other Parts Discussed in Thread: BQ25619, EV2400

I can read the parameters from BQ25619 via EV2400. But, I changed the charge voltage to 4.1V and clicked the W button as indicated in the red circle below. It seems that the new parameter was sent to the charger. but when I read the parameter again, the voltage changed back to 4.2V.  When I use the advanced comm function to write the data to the charger, it shows "Write Block: No acknowledge from device" as shown in the second image below. 

Would you please let me know how to write the parameters into the charger?

  • Hello, 

    Thank you for reaching out via E2E. Firstly when you are in field view on the GUI if you hit read register button does GUI show "Device ACK OK" in upper right of window? Based on your provided image it appears the GUI is showing it is successfully communicating with the EVM. 

    Next when you are in the field view changing the charge voltage dropdown menu from 4.2V to 4.1V will automatically write to the BQ25619 device. There is no need to press the "W" button. 

    Can you please try reading all registers after changing the charge voltage drop down to 4.1V without pressing the 'W" button and see if device reads back correctly? Also please note that registers reset back to default when the watchdog timer expires. To avoid this I recommend you disable the watchdog timer in your testing using REG05 bits 5:4.

    Best Regards,


  • Thank you very much Garrett for your reply. When I hit the read resister button, the GUI does show "Device ACK OK ' 

    I changed two registers (Reg00 and Reg04) at the same time. The charge voltage (Reg04) changed back to the default settings within 13 seconds automatically. While the input current (Reg00) hasn’t changed back to the default value since the new value was written half an hour ago. Could you please help me figure out the reason?

  • Let's disable the watchdog timer and try it again. 

  • Watchdog timer resets the new registers. After it was disabled, the issue was gone.


  • Hi Wen, 

    Great to hear that disabling the watchdog timer fixed the issue. For your knowledge the reason you saw the issue with the charge voltage register, but not the input current limit register is because the input current limit is not reset by watchdog timer expiration as indicated in the reset column of the register map section of the datasheet. 

    Best Regards,