Other Parts Discussed in Thread: BQ34Z100, GPCCHEM
I find my self doing the Chemical ID test for a LiFePo4 battery. The specs for this battery are the follows
- Nominal Voltage = 13.8V
- Capacity = 9Ah
- Cut off Voltage = 10V
- Taper current = 180mA
- Charge Voltage = 14.6V
Two cycles of CHG-REL-DCH-REL were done, each one with the next specifications:
| Item | BAT 0 | BAT 6 |
| Charge Voltage (V) | 14.6 | 14.6 |
| Nominal Capacity (mAhr) | 9000 | 9000 |
| Discharge Stop Voltage (V) | 10.5 | 10 |
| Discharge Current (A) | 1.5 | 0.9 |
Obtaining the next charts (Here are the log files for the tests: roomtemp_rel_dis_rel_1.csv roomtemp_rel_dis_rel_2.csv)
The issue is the results given for the Gauging Parameter Calculator (GPC) Tool, for the first test (QID0) I got this report
Chemistry ID selection tool, rev=2.49 Configuration used in present fit: ProcessingType = 2 NumCellSeries = 4 ElapsedTimeColumn= 0 VoltageColumn = 1 CurrentColumn = 2 TemperatureColumn = 3 Best chemical ID : 457 Best chemical ID max. deviation, % : 7.71 Summary of all IDs with max. DOD deviation below 15% Chem ID max DOD error, % Max R deviation, ratio 457 7.71 0.19 400 11.62 0.6 435 12.63 0.48 6106 12.66 0.34 478 13.53 0.03 414 13.9 0.76 462 14.1 0.46 464 14.35 0.42 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 35.26 3142 bq27421-G1D: 4.4V LiCoO2 35.77 128 bq27421-G1A: 4.2V LiCoO2 3238.2 312 bq27421-G1B: 4.3V LiCoO2 4942.99 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, % 354 bq27621: (ALT_CHEM2) 4.35V LiCoO2 35.26 1210 bq27621: (ALT_CHEM1) 4.3V LiCoO2 42.94 1202 bq27621: (default) 4.2V LiCoO2 2864.32 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 #3 Generic Chem ID Device/ Voltage/ Chemistry max DOD error, % 3230 bq27426: (default) 4.35V LiCoO2 29.38 3142 bq27426: (ALT-CHEM2) 4.4V LiCoO2 35.77 1202 bq27426: (ALT_CHEM1) 4.2V LiCoO2 2864.32 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
Chemistry ID selection tool, rev=2.49 Configuration used in present fit: ProcessingType = 2 NumCellSeries = 4 ElapsedTimeColumn= 0 VoltageColumn = 1 CurrentColumn = 2 TemperatureColumn = 3 Best chemical ID : 6106 Best chemical ID max. deviation, % : 16.51 Summary of all IDs with max. DOD deviation below 15% Chem ID max DOD error, % Max R deviation, ratio 0 0 0 Warning: Deviation is above recommended level. New chem ID needs to be released for this cell. Please contact your TI representative to send the cell to Dallas for characterization 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 30.49 3142 bq27421-G1D: 4.4V LiCoO2 31.89 128 bq27421-G1A: 4.2V LiCoO2 3927.62 312 bq27421-G1B: 4.3V LiCoO2 6099.4 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, % 354 bq27621: (ALT_CHEM2) 4.35V LiCoO2 30.49 1202 bq27621: (default) 4.2V LiCoO2 32.35 1210 bq27621: (ALT_CHEM1) 4.3V LiCoO2 34.1 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 #3 Generic Chem ID Device/ Voltage/ Chemistry max DOD error, % 3230 bq27426: (default) 4.35V LiCoO2 29.25 3142 bq27426: (ALT-CHEM2) 4.4V LiCoO2 31.89 1202 bq27426: (ALT_CHEM1) 4.2V LiCoO2 32.35 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
I would like to know if the discharge current has such an effect on this test. Also, the second test based on the recommended process to do this test (http://www.ti.com/jp/lit/an/slva725a/slva725a.pdf) I don't get a result.
