Other Parts Discussed in Thread: EV2400, BQ78350
Tool/software:
Dear Ti Team,
I would like to bring this critical issue to your attention, as it is highly important for us. We are currently receiving failure feedback from our e-bike batteries in the field.
Our BMS structure includes a BQ78350-R1A gauge along with a BQ7693001DBTR AFE.
Problem: After some time, the communication between the AFE and the gauge is lost.
Once the communication is lost, the battery loses all its functionalities. Furthermore, when we attempt to connect to the gauge via EV2400, we are unable to establish a connection. As a result, we cannot retrieve the lifetime data to analyze the issue.
Upon inspecting the SDA and SCL lines between the AFE and the Gauge, we observed that they remain constantly high (at REGOUT voltage level) without any clock signal. There are no signs of overheating on the ICs.
I researched this issue on forums and found a similar problem discussed in the link below:
BQ78350-R1A: BQ7694001 AFE and BQ78350-R1A no I2C Communication and no SMBus communication with STM32 MCU
Unlike the approach mentioned in the forum, we have not replaced the gauge and AFE. We are aware that firmware ( bq78350_R1_v1_04_build_26 1.srec) can still be loaded onto the gauge even if we cannot read data via EV2400. Therefore, we reloaded the R1A firmware, and after the FW update, the communication was restored. Everything seems to have returned to normal.
Have you encountered this issue before? What is the current status of the problem discussed in the forum? Could you please advise us on the steps we should take?
This issue is critical because when it occurs, the AFE protections fail to operate, and the battery cannot enter shutdown mode. As a result, we are concerned about the batteries entering a deep discharge state.
Your prompt assistance and guidance on this matter would be greatly appreciated.