BQ40Z50-R1: charging is not stable after 5 cycle life

Steel Fang

Part Number: BQ40Z50-R1

Tool/software:

Dear Ti expert,

Our battery is 4S2P, after 5 cycle life testing, the charging is not stable, I save the charging log.

the charging current is always jumping, and we measure the mosfet, it is continuously opening and closing，can you advise the reason for this?

4S2P log.zip

3 days ago

0 Anthony 3 days ago

TI__Mastermind 21940 points

Hi Steel,

Based on the log file, it seems like the charge FET is continuously getting disabled and recovering by the status of the XCHG bit. This bit typically becomes set and disables the charge FET if a protection is triggered. Can you please share the .gg file of the gauge so we can look at the protection thresholds?

Regards,

Anthony

0 Steel Fang 1 day ago in reply to Anthony

Intellectual 280 points

Hi Anthony,

see below for the .gg file.

5050.4S2P.gg.csv

0 Anthony 3 hours ago in reply to Steel Fang

TI__Mastermind 21940 points

Hi Steel,

Thanks for sending these files, we will look into the log file with this in mind now. Regarding the log file, there are several points where the individual cell voltages drop to zero. Are the cells being physically removed at any point or are the secured to the board?

Regards,

Anthony

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BQ40Z50-R1: charging is not stable after 5 cycle life