BQ27500 Remaining capacity is so small

Hello

I would have your help.

My customer is suffering return from market that their product using bq27500.

Bad PCB indicates RM= around 50~60% even though they had insert new battery.

Return is approx 10 from 6,000 total.

Please refer to attached.

I had read gg file from their returned 'bad' pcb and good(original) pcb using i2c. ( attached )

From those , cycle count and Cell 0 Chg DOD at EoC is different.

#Bad pcb

Cycle Count 0 = 8
Update Status 0 = 02
Qmax Cell 1 = 720
Cycle Count 1 = 0
Update Status 1 = 02
Cell 0 Chg dod at EoC = 6462

#Good pcb

Cycle Count 0 = 0
Update Status 0 = 02
Qmax Cell 1 = 720
Cycle Count 1 = 0
Update Status 1 = 02
Cell 0 Chg dod at EoC = 0

Question1

Would you please advice/ estimate why the Bad PCB of RM is so small?

Do you think Cycle count = 8 is something problem? ( i.e. its seemes application issue ?)

Question2

Customer says the issue: RM, is small value ; does not fixed even though they had changed to new battery, and

discharge( C/25 ), charge ( C/3).

Would you please adivse/estimate why bad PCB does not fix the issue?

Question 3

Please adivse what to do next for investigation.

Sorry to bother you, but please advise

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