Other Parts Discussed in Thread: BQ27426
Dear all,
I am developing a new design with LiFePO4 batteries and I am using the bq34z100-g1 to estimate SoC and SoH of the battery.
I have use the GPC tool to find the best CHEM ID, did the procedure shown in SLVA725 document (with bigger relaxing times) and this is the report
Chemistry ID selection tool, rev=2.42 Configuration used in present fit: ProcessingType=2 NumCellSeries=8 ElapsedTimeColumn=0 VoltageColumn=1 CurrentColumn=2 TemperatureColumn=3 Best chemical ID : 414 Best chemical ID max. deviation, % : 5.59 Summary of all IDs with max. DOD deviation below 15% Chem ID max DOD error, % Max R deviation, ratio 0 0 0 Max. deviations for best ID is within recommended range. Chosen best chemical ID is suitable for programming the gauge. Selection of best generic ID for ROM based devices like bq274xx Device / Family #1 Generic Chem ID Device/ Voltage/ Chemistry max DOD error, % 354 bq27411-G1C: 4.35V LiCoO2 42.54 3142 bq27421-G1D: 4.4V LiCoO2 59.26 312 bq27421-G1B: 4.3V LiCoO2 97.59 128 bq27421-G1A: 4.2V LiCoO2 9936.53 Best generic ID 354 Warning: Generic ID Deviation is so high that it is most likely due to anomaly in the data. Please check that data files have recomended format, units and test schedule Device / Family #2 Generic Chem ID Device/ Voltage/ Chemistry max DOD error, % 1202 bq27621: (default) 4.2V LiCoO2 41.44 354 bq27621: (ALT_CHEM2) 4.35V LiCoO2 42.54 1210 bq27621: (ALT_CHEM1) 4.3V LiCoO2 48.22 Best generic ID 1202 Warning: Generic ID Deviation is so high that it is most likely due to anomaly in the data. Please check that data files have recomended format, units and test schedule Device / Family #3 Generic Chem ID Device/ Voltage/ Chemistry max DOD error, % 3230 bq27426: (default) 4.35V LiCoO2 30.79 1202 bq27426: (ALT_CHEM1) 4.2V LiCoO2 41.44 3142 bq27426: (ALT-CHEM2) 4.4V LiCoO2 59.26 Best generic ID 3230 Warning: Generic ID Deviation is so high that it is most likely due to anomaly in the data. Please check that data files have recomended format, units and test schedule Warning: First OCVpoint has non-zero current I= -0.003 Please make sure you have a 2 hr relaxation period before the beginning of discharge. Warning: Last OCVpoint has non-zero current I= -0.002 Please make sure you have a 5 hr relaxation period after the end of discharge.
I have some questions about it:
- I understand best chemical ID suites my LiFePO4 battery is 414. Is this correct?
- What about other Chem ID mentioned in the document for other devices (bq27411, bq27621, bq27426)? I have no intention of using any other device.
Thanks,
