Hi , Thank for the support and sharing the experience.
Battery Spec: Lead-lead dioxide battery is 12V, 5 Ah . kindly check the battery datasheet attached here.
Battery Charger : The charger controls the charging current as well as the charging voltage to safely and efficiently charge the battery. kindly check the battery charging profile attached here.
Battery Discharging Cycle:
Battery is connected to the load ( System : keyboard,display,analog acquisition, 3V regulators 5V regulators ,9V switching regulators ) and the discharge current is 640mA apporximately. [ SOC failed even while rapid change in the discharge current ( Max current 14A ) ] .
Battery Charging Cycle:
Battery is charged at maximum current of 1.2A. ( kindly check the battery charging profile attached here.)
Observation :
- During discharging the battery, state of charge is not update correctly ( ex. System shall switch off if battery voltage is 11.2V but SOC is 96% at 11.2V ) .
- While start charging the drained battery( 11.2V ), SOC is updated as above 45%
Why the BQ34Z110 fail to provide correct State Of Charge?
Do any design recommendations are available to avoid SOC failure?
Kindly check the attached information and share the suggestions.
Golden Image
[Header] bq EVSW Version = 0.9.90 DeviceName = bq34z110 v0.04 Time = 06-05-2016 09:43:40 [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 = 55.0 Temp Hys = 5.0 [Charge(Configuration)] Suspend Low Temp = -5.0 Suspend High Temp = 55.0 Chg Eff = 100 Chg Eff Temp Comp = 25 Chg Eff Drop Off % = 96 Chg Eff Reduction Rate = 10 Maintenance Current = 0 [Charge Termination(Configuration)] Taper Current = 143 Min Taper Capacity = 25 Cell Taper Voltage = 100 Current Taper Window = 40 TCA Set % = 99 TCA Clear % = 95 FC Set % = -1 FC Clear % = 98 DODatEOC Delta T = 10.0 [Data(Configuration)] Rem Cap Alarm = 100 Design Cell Voltage = 2000 Initial Standby = -10 Initial MaxLoad = -500 Manuf Date = 06-May-2016 Ser. Num. = 0001 Cycle Count = 66 CC Threshold = 900 Design Cell Capacity = 5000 Design Cell Energy = 11750 SOH Load I = -400 TDD SOH Percent = 90 Cell Charge Voltage T1-T2 = 2250 Cell Charge Voltage T2-T3 = 2450 Cell Charge Voltage T3-T4 = 2350 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 = bq34z110 Manufacturer Name = Texas Inst. Device Chemistry = PbA [Discharge(Configuration)] SOC1 Set Threshold = 150 SOC1 Clear Threshold = 175 SOCF Set Threshold = 75 SOCF Clear Threshold = 100 Cell BL Set Volt Threshold = 1750 Cell BL Set Volt Time = 2 Cell BL Clear Volt Threshold = 1800 Cell BH Set Volt Threshold = 2450 Cell BH Volt Time = 2 Cell BH Clear Volt Threshold = 2400 [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 = 64.5 Lifetime Min Temp = 20.0 Lifetime Max Chg Current = 2904 Lifetime Max Dsg Current = -11630 Lifetime Max Pack Voltage = 65530 Lifetime Min Pack Voltage = 0 [Lifetime Temp Samples(Configuration)] LT Flash Cnt = 48 [Registers(Configuration)] Pack Configuration = 0971 Pack Configuration B = FE Pack Configuration C = 30 LED_Comm Configuration = 00 Alert Configuration = 0000 Number of series cell = 6 [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 = 1000 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 = 2 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 = 100 Cell Terminate Voltage = 1750 Cell Term V Delta = 25 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 = 100 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 = 60 Chg Current Threshold = 75 Quit Current = 40 Dsg Relax Time = 60 Chg Relax Time = 60 Quit Relax Time = 1 Cell Max IR Correct = 400 [State(Gas Gauging)] Qmax Cell 0 = 5000 Cycle Count = 61 Update Status = 06 Cell V at Chg Term = 2357 Avg I Last Run = -299 Avg P Last Run = -1131 Cell Delta Voltage = 2 T Rise = 20 T Time Constant = 1000 [OCVa Table(OCV Table)] Chem ID = 0800 [R_a0(Ra Table)] Cell0 R_a flag = FF55 Cell0 R_a 0 = 83 Cell0 R_a 1 = 66 Cell0 R_a 2 = 56 Cell0 R_a 3 = 51 Cell0 R_a 4 = 47 Cell0 R_a 5 = 47 Cell0 R_a 6 = 49 Cell0 R_a 7 = 56 Cell0 R_a 8 = 59 Cell0 R_a 9 = 64 Cell0 R_a 10 = 72 Cell0 R_a 11 = 83 Cell0 R_a 12 = 150 Cell0 R_a 13 = 267 Cell0 R_a 14 = 275 [R_a0x(Ra Table)] xCell0 R_a flag = FFFF xCell0 R_a 0 = 83 xCell0 R_a 1 = 66 xCell0 R_a 2 = 56 xCell0 R_a 3 = 51 xCell0 R_a 4 = 47 xCell0 R_a 5 = 47 xCell0 R_a 6 = 49 xCell0 R_a 7 = 56 xCell0 R_a 8 = 59 xCell0 R_a 9 = 64 xCell0 R_a 10 = 72 xCell0 R_a 11 = 83 xCell0 R_a 12 = 150 xCell0 R_a 13 = 267 xCell0 R_a 14 = 275 [Data(Calibration)] CC Gain = 10.674 CC Delta = 10.653 CC Offset = -0.69 Board Offset = -0.45 Int Temp Offset = 0.0 Ext Temp Offset = 0.0 Voltage Divider = 16041 [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
Battery Datasheet
Battery charging profile
Thank you