BQ2084-V143: Cell Imbalance detection

Pietro Vignali

Intellectual 905 points

Part Number: BQ2084-V143
Other Parts Discussed in Thread: BQ29312A

Hello

I'm investigating an old project based on bq2084+bq29312A.

I have a pack with a sever cell imbalance > 2000mV, and I'm expecting to see the PF CIMB flag to be set but nothing.

I think all the settings are in place:

Cell Imbalance Threshold 0xEE-0xEF: 500mV
Balance IMAX 0xF2-0xF3: 10mA
Cell Imbalance Time 0x134: 20s

When the pack is charging (precharging because of the imbalanced cell is < 2000mV) with approx 20mA, the Max imbalance is not detected and the PF-CIMB flag is not set.

What other settings need to be set to activate the critical imbalance condition to be detected ?

Thanks

Pietro

over 4 years ago

0 Wyatt Keller over 4 years ago

TI__Guru** 103125 points

Hello Pietro,

Could you provide the .GG file of your setup so we can look further into the settings?

Sincerely,

Wyatt Keller

0 Pietro Vignali over 4 years ago in reply to Wyatt Keller

Intellectual 905 points

Hello Wyatt

Please find attached the settings and a hex dump.

I don't have a proper GG file generated by TI apps, but I have the same data in CSV format generated by one of our internal tools.

Please let me know what do you find

Thanks

Pietro

Parameter Table.csv

HexDump Battery 03367.csv

0 Kang Kang over 4 years ago in reply to Pietro Vignali

TI__Mastermind 24870 points

Hello Pietro,

The gg.csv file is not very useful.

Can you use TI tool chains to re-generate the files we need?

0 Pietro Vignali over 4 years ago in reply to Kang Kang

Intellectual 905 points

Hello Kang,

Kang Kang said:

The gg.csv file is not very useful.
Can you use TI tool chains to re-generate the files we need?

Here it is:

bat03367.zip

Please let me know, thanks
Pietro

0 Wyatt Keller over 4 years ago in reply to Pietro Vignali

TI__Guru** 103125 points

Hello Pietro,

Can you get a log file of the precharge you're doing on the cell? This will help us see what the gauge is doing.

Sincerely,

Wyatt Keller

0 Pietro Vignali over 4 years ago in reply to Wyatt Keller

Intellectual 905 points

Hello Wyat,

I did a logo while in precharge (approx 20mA), please get the log here attached.
bat03367-cell-imbalance.zip

Awaiting for yor reply.

Thanks

0 Wyatt Keller over 4 years ago in reply to Pietro Vignali

TI__Guru** 103125 points

Hello Pietro,

I have been reviewing your log file, have you checked to make sure the XCIM bit allows for the PF flag to be set? Check to make sure you have the correct configuration for XCIM. Try setting it and seeing if you can see the interrupt.

It's in the TRM: PF Config DF 0x11f, page 25.

Sincerely,

Wyatt Keller

0 Pietro Vignali over 4 years ago in reply to Wyatt Keller

Intellectual 905 points

Wyatt,

this BMS doesn't have a fuse so the PF Config is not set, but from past experience, PF status bits for SOV, AFE, etc were fired correctly in case of errors, even without setting PF Config.

Today I set PF Config for XCIMB (bit4), RESET, and set the pack in charge.
Some cells are approx 3300mV, just one is 1000mV, and so the pack is just pre-charging at 20mA.
Even after several minutes of charging, the PF CIM flag is yet not set.

What are the exact conditions to set this alarm, please ?

Thanks in advance

Pietro

0 Wyatt Keller over 4 years ago in reply to Pietro Vignali

TI__Guru** 103125 points

Hello Pietro,

It looks like you have everything configured correctly, let me check with the firmware team to see what conditions would cause it not to trigger.

Sincerely,

Wyatt Keller

0 Andy Liu (BMS) over 4 years ago in reply to Wyatt Keller

TI__Guru 52115 points

I will check with Wyatt about the update.

Andy

0 Wyatt Keller over 4 years ago in reply to Andy Liu (BMS)

TI__Guru** 103125 points

Hello,

The firmware team has been very busy and hasn't had gotten back to me yet.

Is this issue still persisting?

Sincerely,

Wyatt Keller

0 Pietro Vignali over 4 years ago in reply to Wyatt Keller

Intellectual 905 points

No problem.

Regards

Power management

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BQ2084-V143: Cell Imbalance detection