BQ40Z80EVM-020: Chemistry affection on Data Flash Tables

Vladimir Yershov76

Intellectual 290 points

Part Number: BQ40Z80EVM-020
Other Parts Discussed in Thread: BQSTUDIO

Hello,

In bqStudio I loaded new chemistry for LiFePO4 batteries, instead of LiON ones.

I expected, that all related mV settings entries in Data Memory had to scale for new values.

But I see no changes at all.

Does it mean, that I have to manually perform neccessary changings?

Thanks in advance,

Vladimir

over 5 years ago

0 Vladimir Yershov76 over 5 years ago

Intellectual 290 points

Exported dd.csv files with old and new chemistries are the same.

0 Andy Liu (BMS) over 5 years ago in reply to Vladimir Yershov76

TI__Guru 52115 points

I believe the Ra table should be different in the gg file.

Can you share the two gg files before and after you changed the chemistry id?

Andy

0 Vladimir Yershov76 over 5 years ago in reply to Andy Liu (BMS)

Intellectual 290 points

Sure.

Differenses are in srec files.

Second moment:

I started learn cycle with FET_EN=1 and GAUGE_EN=1, Lstatus = 4. And I observe strange behaovior: CHG and DSG fets became switching ON for 1s, then switch OFF for 1s, etc. It lasted til the end of discharge phase. Unfortunatelly, during the procedure, mains in my house twice interrupted, so I had to twice restart the prcedure. I attached two log files.

6574.Files.zip 2100.LOG.ZIP

0 Andy Liu (BMS) over 5 years ago in reply to Vladimir Yershov76

TI__Guru 52115 points

I can confirm that the OCV and Ra tables in the two srec files are different.

Make sure you click the Read All button in the Data Memory after you change the chemistry id in the Chemistry tab. I guess you probably forgot to do that.

Andy

0 Vladimir Yershov76 over 5 years ago in reply to Andy Liu (BMS)

Intellectual 290 points

Yes, I was wrong. Mistakely snapshot the same Data Memory tables.

But the question remains.

Differences in Data Memory files are only in Ra Tables.

What about voltages settings?

They remains for LION(3.7V cell voltage) though I changed Chemistry to LiFePO4(3.3V cell voltage).

0 Wyatt Keller over 5 years ago in reply to Vladimir Yershov76

TI__Guru** 105740 points

Hello,

When you update the chemistry ID you update the Ra table and some other private parameters. You will need to manually update other voltages in the data memory to match your new battery.

Sincerely,

Wyatt Keller

0 Vladimir Yershov76 over 5 years ago in reply to Wyatt Keller

Intellectual 290 points

BINGO!
And thank you very much.

That is the moment of truth!
Would you be kind to indicate precisely what settings are mandatory for update?
I could not find this info in available documents.

Thanks in advance,
Vladimir

0 Andy Liu (BMS) over 5 years ago in reply to Vladimir Yershov76

TI__Guru 52115 points

I would suggest you start with this app note below.

https://www.ti.com/lit/an/slua848/slua848.pdf

Andy

0 Vladimir Yershov76 over 5 years ago in reply to Andy Liu (BMS)

Intellectual 290 points

Bravo, Andy!

Actually, I did not expect another answer.
The two most popular answers from TI staff, yours and read SLVA725A.

Are you not confused by the fact that my question was inspired by exactly reading slua848?

0 Kang Kang over 5 years ago in reply to Vladimir Yershov76

TI__Mastermind 24870 points

Hello Vladimir,

I think you are referring to design voltage, design capacity, etc...

Section 3 contains the minimum set of parameters you need to change to start the learning cycle.

Thanks

Power management

Power management forum

BQ40Z80EVM-020: Chemistry affection on Data Flash Tables