BQ27520-G4: FCC is not reaching the design capacity

Hi Anna,

1.FCC is not reaching the design capacity.Why is it so?What is the calculation used to find the FCC during the first insertion of the battery?

FCC=Qstart+PassedCharge+RM, it will updated during the discharge and charge cycle. When first insert, it isn't equal to design capacity.

2.How full available capacity is calculated during the first insertion of the battery?

Full available capacity has a proportion like 90% relationship with Design capacity.

3.How nominal available capacity is related to full available capacity?

Nominal available capacity conrespond to uncompensated remain capacity, when first insert battery, it was estimated by voltage.

4.UnfilteredRM( ):This read-only command pair returns the compensated battery capacity remaining.What is mean by compensation and uncompensation?

Compensation means we use some mathamtic method to deal with the discharge curve to solve some transient problem.

Attached file could help you understand well.8306.theory and implementation of impedance track-battery fuel gauging algorithm in BQ2750x.pdf

Thanks.

Best regards,

Sammi