BQ40Z80: Problems charging

richard wilson

Part Number: BQ40Z80
Other Parts Discussed in Thread: GPCCHEM,

Hi ,

With a new battery, we download the gg file and charge but the battery keeps failing to charge with one of two problems , one is the OT flag and the other is the OC flag. The OT timeout is set to 4 hours and the charge termination is set to cell termination so I don't understand why either of these flags is being set. Could you take a look at the gg file attached and let me know if there is a mistake in the settings file?

Thank you

Richard

RECHARGEABLE_Reworked Values_Manual Entry_2023_01_25_CTO_TOPCURRENT_CHANGED.gg.csv

over 2 years ago

0 Wyatt Keller over 2 years ago

TI__Guru** 105760 points

Hello Richard,

Please share the log file along with the .gg file for us to analyze.

If you are getting OT and OC set then you need to adjust the over temperature conditions to align with your application, or disable the protection if you don't want it. For OC usually this means you do not have your VCT conditions in the correct place and your Advanced Charge Algorithm settings may need to be adjusted.

Sincerely,

Wyatt Keller

0 richard wilson over 2 years ago in reply to Wyatt Keller

Intellectual 585 points

Hi ,

thank you for your reply, I have attached a log with a failed charge. This pack has previously charged without error. Could you take a look at the log and let me know what the likely cause is, maybe its a setting that needs adjustment. As far as I can work out, the OC flag is set and then CTOS is set but the cell voltages are not near top of charge.

8023101_005_1ACharge_20230229_CHG_FET_TURNED_OFF.xlsx

Thank you very much in advance,

Richard

0 Wyatt Keller over 2 years ago in reply to richard wilson

TI__Guru** 105760 points

Hello Richard,

Have you completed a learning cycle and found a chem ID with the GPCCHEM tool before your testing? You LStatus register is showing 8, usually it should either be 0x06 or 0x0e, it seems that all the learning steps may not have been taken. Also your DOD at EOC points are 0, and cell 2 is 1000 which is probably too high, so I think the settings are not correct for your battery.

If the gauging settings are not correct the OC flag will easily set because FCC is not calculated correctly.

I would review the app notes and FAQs on on FAQ home page for Impedance Track and the BQ40Z80 gauge:

https://e2e.ti.com/support/power-management-group/power-management/f/power-management-forum/1127899/faq-bq40z80-faqs?tisearch=e2e-sitesearch&keymatch=faq%3Atrue

https://e2e.ti.com/support/power-management-group/power-management/f/power-management-forum/1100653/faq-impedance-track-faqs

Sincerely,

Wyatt Keller

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BQ40Z80: Problems charging