Other Parts Discussed in Thread: BQSTUDIO,
Bq20z45 pack in 4s1p configuration.
Cells are PLB IFR 2665
CHEM ID 0494
Nominal Capacity 3300mAh
GG file and log files can be provided.
RemainingCapacity and FullChargeCapacity do not reflect the actual capacity during discharge.
Why does the Fuel Gauge not reflect the RemainingCapacity of the battery accurately and why does the FullChargeCapacity decline?
A discharge of a pack was completed from Full to Empty. Full was defined a taper current at 120ma and Empty defined at pack voltage 10V. The FullChargeCapacity started at 2494mAh and ended at 2400mAh after more than 5 hours of rest. During discharge, the FullChargeCapacity did change several times. The RemainingCapacity tracked the FullChargeCapacity for the first 90minutes of a constant 650ma discharge rate before the RemainingCapacity starts declining to zero after 5 hours of discharge.
The capacity measured 3392mAh (from bqStudio log) and 3378mAh (from Arbin battery tester).
The image shows a graph of the flat area of RemainingCapacity for 1.5hours before a steady decline to zero . During the flat area, FullChargeCapacity was 2432, 2431 or 2433.