BQ76942: Cell undervoltage protection not working as expected

Nevena Maric

Part Number: BQ76942

Hi,

I have problem with cell undervoltage protection. It is only activated when all cells are below certain threshold.

Based on what I read in the user manual, I expected that when cell with minimum voltage falls below defined threshold that it will then activate cell undervoltage protection.

I would be grateful for clarification and advice if I may have missed configuring some of the registers correctly.

Best regards,

Nevena

7 months ago

0 Andria McIntyre 7 months ago

TI__Expert 8461 points

Hi Nevena,

I recommend looking through Section 5.2.5 in the TRM (BQ76952 Technical Reference Manual (Rev. B) (ti.com)) for more information on CUV configuration. If you are still facing issues after this, please feel free to respond and attach your gg.csv file.

Best,

Andria

0 Nevena Maric 6 months ago

Prodigy 50 points

Hi Andria,

I am still facing issues with undervoltage protection. I would like to attach gg.csv file, but I have problems with BQ studio (version 1.3.124).

Until now, I did balancer configuration with MCU. Before connecting with BQ studio I deinitalized I2C peripheral on MCU that I used for communication with balancer. I can still read some registers with BQ studio such as cell voltages, but a lot of them can't be read. I am getting notification about CRC error as you can see on attached images.

Can you please help me to resolve this issue?

Best,

Nevena

0 Andria McIntyre 6 months ago in reply to Nevena Maric

TI__Expert 8461 points

Hi Nevena,

I am sorry to hear that you are still facing issues. Unfortunately, I am not able to open google drive photos. If you can tell me the register settings, even if they are not in gg.csv file format, that would be helpful.

Best,

Andria

+1 Nevena Maric 6 months ago

Prodigy 50 points

Hi Andria,

I managed to resolve issuses with undervoltage protection and with BQ Studio.

After updating firmware on EV400, I managed to read bq76942 registers properly with BQ studio.

Problem with the undervoltage protection was wrong configuration of the VCELL MODE register.

Best,

Nevena

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BQ76942: Cell undervoltage protection not working as expected