Hello.
I trying use bq34z100 with 4-parallel NCR18650 Panasonic (2900ma) battery set, but after testing got very bad results. Please check my records, maybe you can give me recommendation for improving working with this ICs.
At first I set config for my battery specification and received golden image (file "config.gg"). Here three graphs of Remaining Capacity prediction in calibration progress when discharging (graph1).
As you can see, the last (3) curve has a very good precision, if draw a line for the end (graph2 is zooming) we get about 1.1% accuracy in overall. But shape of the graph is not very good for real use, because it have unknown step-fluctuation (with sharp jumping of % capacity about 2%, see graph1). Besides, prediction capacity is over before voltage reached minimal value. Please see graph3 with end of third calibration curve with imposed voltage curve. As I understand, prediction capacity must be related with current voltage according chemical table (for my type of battery NCR18650, wich be uploaded before calibration), but correction too juddering, even it is.
Here measurements on a less current ~1.3A, results not bad (see graph4), exept step-down at the end.
Here measurements on a larger current ~4A (see graph5), and results not very good - curve of remaining capacity prediction fall down on about 9% earlier of real capacity. And again we see a several big step-fluctuation (as I understand this is may be a fault of comparing with chemical table).
And next battery prediction testing at different from calibrated temperature on about -16C. Results very poor. (see graph 6) Curve has giant steps without any correlation with real capacity.
However, once I noticed, that counting on charging is not work correctly at the end of charge. Capacity counting just stops on certain value and not count some % of energy. Its happend while charging battery after it was fully discharged at -16C temperature, then heated by the room temperature with restoring remaining capacity to about 2000ma. See graph7.
So, as I see capacity prediction is not work correctly, but cant find reason for this.
Q1. Whether it is possible smoothing graph of remaining capacity prediction to eliminate step-correction of prediction?
Q2. Is it possible eliminate graph break at the end and strech it according minimal voltage value?
Q3. How to reach good working bq34z100 with my battery on terms different from first calibration (20C, 2A)?
Q4. Why there was a failure of capacity counting on charging?
PS: Im sure that chemical of my battery is the same as I choose in chemical selection list (NCR18650 2900ma code 0238), temperature probe has good thermal contact with battery, was placed between nearby elements and is correctly type (103AT 3435K), all elements brand-new and fresh. I attach photo of my testing setup and full log in four files of all my tests.
I will be grateful for any advice.
With best regards, Viktor.
[Header] bq EVSW Version = 0.9.90 DeviceName = bq34z100 v0.06 Time = 14.04.2014 16:56:57 [Safety(Configuration)] OT Chg = 55.0 OT Chg Time = 2 OT Chg Recovery = 50.0 OT Dsg = 60.0 OT Dsg Time = 2 OT Dsg Recovery = 55.0 [Charge Inhibit Cfg(Configuration)] Chg Inhibit Temp Low = 0.0 Chg Inhibit Temp High = 45.0 Temp Hys = 5.0 [Charge(Configuration)] Suspend Low Temp = -5.0 Suspend High Temp = 55.0 [Charge Termination(Configuration)] Taper Current = 300 Min Taper Capacity = 4 Cell Taper Voltage = 150 Current Taper Window = 40 TCA Set % = 99 TCA Clear % = 95 FC Set % = 100 FC Clear % = 98 DODatEOC Delta T = 10.0 [Data(Configuration)] Rem Cap Alarm = 100 Initial Standby = -10 Initial MaxLoad = -500 Manuf Date = 01-ѳ�-1980 Ser. Num. = 0001 Cycle Count = 3 CC Threshold = 10440 Design Capacity = 11600 Design Energy = 32000 SOH Load I = -4000 TDD SOH Percent = 90 Cell Charge Voltage T1-T2 = 4200 Cell Charge Voltage T2-T3 = 4200 Cell Charge Voltage T3-T4 = 4100 Charge Current T1-T2 = 10 Charge Current T2-T3 = 50 Charge Current T3-T4 = 30 JEITA T1 = 0 JEITA T2 = 10 JEITA T3 = 45 JEITA T4 = 55 ISD Current = 10 ISD I Filter = 127 Min ISD Time = 7 Design Energy Scale = 1 Device Name = nk2bat Manufacturer Name = vrp-lights Device Chemistry = LION [Discharge(Configuration)] SOC1 Set Threshold = 660 SOC1 Clear Threshold = 800 SOCF Set Threshold = 330 SOCF Clear Threshold = 450 Cell BL Set Volt Threshold = 3100 Cell BL Set Volt Time = 2 Cell BL Clear Volt Threshold = 3200 Cell BH Set Volt Threshold = 4300 Cell BH Volt Time = 2 Cell BH Clear Volt Threshold = 4200 [Manufacturer Data(Configuration)] Pack Lot Code = 0000 PCB Lot Code = 0000 Firmware Version = 0000 Hardware Revision = 0000 Cell Revision = 0000 DF Config Version = 0000 [Integrity Data(Configuration)] Static Chem DF Checksum = 0000 [Lifetime Data(Configuration)] Lifetime Max Temp = 30.0 Lifetime Min Temp = 15.2 Lifetime Max Chg Current = 4156 Lifetime Max Dsg Current = -2061 Lifetime Max Pack Voltage = 4198 Lifetime Min Pack Voltage = 2855 [Lifetime Temp Samples(Configuration)] LT Flash Cnt = 39 [Registers(Configuration)] Pack Configuration = 0161 Pack Configuration B = FF Pack Configuration C = 30 LED_Comm Configuration = 00 Alert Configuration = 0000 Number of series cell = 1 [Lifetime Resolution(Configuration)] LT Temp Res = 1.0 LT Cur Res = 100 LT V Res = 25 LT Update Time = 60 [LED Display(Configuration)] LED Hold Time = 4 [Power(Configuration)] Flash Update OK Cell Volt = 2800 Sleep Current = 10 FS Wait = 0 [Manufacturer Info(System Data)] Block A 0 = 00 Block A 1 = 00 Block A 2 = 00 Block A 3 = 00 Block A 4 = 00 Block A 5 = 00 Block A 6 = 00 Block A 7 = 00 Block A 8 = 00 Block A 9 = 00 Block A 10 = 00 Block A 11 = 00 Block A 12 = 00 Block A 13 = 00 Block A 14 = 00 Block A 15 = 00 Block A 16 = 00 Block A 17 = 00 Block A 18 = 00 Block A 19 = 00 Block A 20 = 00 Block A 21 = 00 Block A 22 = 00 Block A 23 = 00 Block A 24 = 00 Block A 25 = 00 Block A 26 = 00 Block A 27 = 00 Block A 28 = 00 Block A 29 = 00 Block A 30 = 00 Block A 31 = 00 [IT Cfg(Gas Gauging)] Load Select = 1 Load Mode = 0 Max Res Factor = 15 Min Res Factor = 3 Ra Filter = 500 Fast Qmax Start DOD % = 92 Fast Qmax End DOD % = 96 Fast Qmax Start Volt Delta = 200 Cell Terminate Voltage = 2950 Cell Term V Delta = 50 ResRelax Time = 200 User Rate-mA = 0 User Rate-Pwr = 0 Reserve Cap-mAh = 0 Reserve Energy = 0 Max Scale Back Grid = 4 Cell Max DeltaV = 200 Cell Min DeltaV = 0 Max Sim Rate = 2 Min Sim Rate = 20 Ra Max Delta = 44 Qmax Max Delta % = 5 Cell DeltaV Max Delta = 10 Fast Scale Start SOC = 10 Charge Hys V Shift = 40 [Current Thresholds(Gas Gauging)] Dsg Current Threshold = 50 Chg Current Threshold = 75 Quit Current = 30 Dsg Relax Time = 60 Chg Relax Time = 60 Quit Relax Time = 1 Cell Max IR Correct = 400 [State(Gas Gauging)] Qmax Cell 0 = 11274 Cycle Count = 3 Update Status = 06 Cell V at Chg Term = 4195 Avg I Last Run = -2040 Avg P Last Run = -7366 Cell Delta Voltage = 1 T Rise = 20 T Time Constant = 1000 [OCVa Table(OCV Table)] Chem ID = 0107 [R_a0(Ra Table)] Cell0 R_a flag = 0000 Cell0 R_a 0 = 22 Cell0 R_a 1 = 21 Cell0 R_a 2 = 41 Cell0 R_a 3 = 54 Cell0 R_a 4 = 64 Cell0 R_a 5 = 91 Cell0 R_a 6 = 113 Cell0 R_a 7 = 129 Cell0 R_a 8 = 134 Cell0 R_a 9 = 140 Cell0 R_a 10 = 153 Cell0 R_a 11 = 180 Cell0 R_a 12 = 186 Cell0 R_a 13 = 173 Cell0 R_a 14 = 401 [R_a0x(Ra Table)] xCell0 R_a flag = 0055 xCell0 R_a 0 = 34 xCell0 R_a 1 = 32 xCell0 R_a 2 = 62 xCell0 R_a 3 = 82 xCell0 R_a 4 = 98 xCell0 R_a 5 = 139 xCell0 R_a 6 = 172 xCell0 R_a 7 = 197 xCell0 R_a 8 = 204 xCell0 R_a 9 = 213 xCell0 R_a 10 = 233 xCell0 R_a 11 = 274 xCell0 R_a 12 = 283 xCell0 R_a 13 = 264 xCell0 R_a 14 = 611 [Data(Calibration)] CC Gain = 10.107 CC Delta = 10.088 CC Offset = -0.69 Board Offset = 0 Int Temp Offset = 0.0 Ext Temp Offset = 0.0 Voltage Divider = 4992 [Current(Calibration)] Deadband = 5 [Codes(Security)] Sealed to Unsealed = 36720414 Unsealed to Full = FFFFFFFF Authen Key3 = 01234567 Authen Key2 = 89ABCDEF Authen Key1 = FEDCBA98 Authen Key0 = 76543210
