Other Parts Discussed in Thread: GPCCHEM
Good afternoon!
There is a problem with the BMS based on BQ40Z80.
The BMS is configured to 7S2P battery, cells are Panasonic NCR2070C, nominal cells capacity is 3500 mAh. There is no such model of the cell in the chemistry programming options of Battery Management Studio.
To select the best chemical ID, we performed a charge-relax-discharge-relax cycle according to Simple Guide to chemical ID Selection Tool (SLVA725A). The results of the cycle are attached. The cycle was performed on an absolutely new battery. As can be seen from the results of the cycle, the battery capacity is around 6,86 Ah, which is 98% of the nominal battery capacity.
We sent the results to TI via Gauging Parameter Calculator and received a strange report (attached). The report contains a list of various chem IDs that should fit our battery. It is strange that the IDs are completely different in capacity from our cells, and also from each other.
We tried to program all of the 10 recommended chem IDs on two batteries with absolutely new cells (the first battery is fully discharged and the second battery is half-charged) and there were different results but in all the experiments the SoH of the batteries didn’t reach 100% and even 98%. Results of the experiments are attached.
What could be the reason for this problem?
Is there any way to force the SOH of the new battery to 100%?
Data memory contents are attached.
Learning 901LI22000425-report.zipResults of testing of different chemistries.xlsx0721_0001.gg.csvLearning 901LI22000425.zip
