Hi,
Please see above: The pack has cell imbalance issue and the actual cycles count is reach 385 before it could not consistently hold charge. our target is get into 450 cycles count. What are the scenarios to cause cell imbalance with this chip?
Thank you
I also exported the dataflash below:
[Header]
bq EVSW Version = 0.9.90
DeviceName = bq20z45R1 v1.05
Time = 1/26/2016 3:44:27 PM
[Voltage(1st Level Safety)]
LT COV Threshold = 4450
LT COV Recovery = 4250
ST COV Threshold = 4450
ST COV Recovery = 4250
HT COV Threshold = 4450
HT COV Recovery = 4250
CUV Threshold = 2450
CUV Time = 2
CUV Recovery = 3150
[Current(1st Level Safety)]
OC (1st Tier) Chg = 2400
OC (1st Tier) Dsg = 3100
OC (1st Tier) Dsg Time = 2
Current Recovery Time = 8
AFE OC Dsg = 08
AFE OC Dsg Time = 05
AFE SC Chg Cfg = 51
AFE SC Dsg Cfg = 51
[Temperature(1st Level Safety)]
OT1 Chg Threshold = 50.0
OT1 Chg Time = 2
OT1 Chg Recovery = 40.0
OT2 Chg Threshold = 0.0
OT2 Chg Time = 0
OT2 Chg Recovery = 0.0
OT1 Dsg Threshold = 65.0
OT1 Dsg Time = 2
OT1 Dsg Recovery = 55.0
OT2 Dsg Threshold = 0.0
OT2 Dsg Time = 0
OT2 Dsg Recovery = 0.0
Hi Dsg Start Temp = 60.0
[Voltage(2nd Level Safety)]
LT SOV Threshold = 4550
ST SOV Threshold = 4550
HT SOV Threshold = 4550
SOV Time = 5
PF SOV Fuse Blow Delay = 5
SUV Threshold = 2000
SUV Time = 5
Rest CIM Current = 5
Rest CIM Fail Voltage = 1000
Rest CIM Time = 5
CIM Battery Rest Time = 1800
Rest CIM Check Voltage = 3000
Active CIM Fail Voltage = 1000
Active CIM Time = 5
Active CIM Check Voltage = 3000
PFIN Detect Time = 5
PF Min Fuse Blow Voltage = 7000
[Current(2nd Level Safety)]
SOC Chg = 4000
SOC Chg Time = 1
SOC Dsg = 6000
SOC Dsg Time = 1
[Temperature(2nd Level Safety)]
SOT1 Chg Threshold = 55.0
SOT1 Chg Time = 5
SOT2 Chg Threshold = 65.0
SOT2 Chg Time = 0
SOT1 Dsg Threshold = 75.0
SOT1 Dsg Time = 5
SOT2 Dsg Threshold = 75.0
SOT2 Dsg Time = 0
[FET Verification(2nd Level Safety)]
FET Fail Time = 5
[AFE Verification(2nd Level Safety)]
AFE Check Time = 30
AFE Fail Limit = 10
AFE Fail Recovery Time = 20
[Charge Temp Cfg(Charge Control)]
JT1 = 0.0
JT2 = 12.0
JT2a = 30.0
JT3 = 45.0
JT4 = 50.0
Temp Hys = 1.0
[Pre-Charge Cfg(Charge Control)]
Pre-chg Voltage Threshold = 3050
Pre-chg Recovery Voltage = 3150
Pre-chg Current = 100
[Charge Cfg(Charge Control)]
LT Chg Voltage = 12450
LT Chg Current1 = 780
LT Chg Current2 = 780
LT Chg Current3 = 780
ST1 Chg Voltage = 13050
ST1 Chg Current1 = 1550
ST1 Chg Current2 = 1550
ST1 Chg Current3 = 1550
ST2 Chg Voltage = 13050
ST2 Chg Current1 = 1550
ST2 Chg Current2 = 1550
ST2 Chg Current3 = 1550
HT Chg Voltage = 12750
HT Chg Current1 = 1240
HT Chg Current2 = 1240
HT Chg Current3 = 1240
Cell Voltage Threshold1 = 3900
Cell Voltage Threshold2 = 4000
Cell Voltage Thresh Hys = 10
[Termination Cfg.(Charge Control)]
Taper Current = 160
Taper Voltage = 75
TCA Clear % = 95
FC Clear % = 95
[Cell Balancing Cfg(Charge Control)]
Min Cell Deviation = 1350
[Charging Faults(Charge Control)]
Over Charge Capacity = 620
Charge Fault Cfg = 00
[Data(SBS Configuration)]
Rem Cap Alarm = 310
Rem Energy Alarm = 3490
Rem Time Alarm = 10
Init Battery Mode = 0001
Design Voltage = 11250
Spec Info = 0031
Manuf Date = 18-Mar-2014
Ser. Num. = 00DD
Cycle Count = 385
CC Threshold = 2790
CF MaxError Limit = 100
Design Capacity = 3100
Design Energy = 34880
Manuf Name = TOTEX
Device Name = S441
Device Chemistry = LION
Deterioration Warn Limit = 50
Deterioration Fault Limit = 30
Cell Life Limit = 20
[Configuration(SBS Configuration)]
TDA Set % = 6
TDA Clear % = 8
FD Set % = 2
FD Clear % = 5
TDA Set Volt Threshold = 3750
TDA Set Volt Time = 5
TDA Clear Volt = 4125
[Manufacturer Info(System Data)]
Manuf. Info 0 = LG ICR18650E1
Manuf. Block 1 = Rev0
Manuf. Block 2 = 0123456789ABCDEF0123
Manuf. Block 3 = 0123456789ABCDEF0123
Manuf. Block 4 = 0123456789ABCDEF0123
[Lifetime Data(System Data)]
Lifetime Max Temp = 62.2
Lifetime Min Temp = 15.2
Lifetime Max Cell Voltage = 4451
Lifetime Min Cell Voltage = 2446
Lifetime Max Pack Voltage = 13041
Lifetime Min Pack Voltage = 8322
Lifetime Max Chg Current = 1580
Lifetime Max Dsg Current = -3000
Lifetime Max Chg Power = 20080
Lifetime Max Dsg Power = -17990
Life Max AvgDsg Cur = -2000
Life Max AvgDsg Pow = -3022
Life Avg Temp = 25.4
[Lifetime Temp Samples(System Data)]
LT Temp Samples = 264876
[Registers(Configuration)]
Operation Cfg A = 0229
Operation Cfg B = 2CC8
Operation Cfg C = 0170
Permanent Fail Cfg = 0000
Permanent Fail Cfg 2 = 0000
Non-Removable Cfg = 0000
[AFE(Configuration)]
AFE.State_CTL = 00
[Power(Power)]
Flash Update OK Voltage = 8850
Shutdown Voltage = 7350
Shutdown Time = 10
Cell Shutdown Voltage = 1750
Cell Shutdown Time = 10
Charger Present = 3000
Sleep Current = 20
Wake Current Reg = 00
Sealed Ship Delay = 5
[IT Cfg(Gas Gauging)]
Load Select = 3
Load Mode = 1
Term Voltage = 7650
User Rate-mA = 0
User Rate-mW = 0
Reserve Cap-mAh = 0
Reserve Cap-mWh = 0
Ra Max Delta = 44
[Current Thresholds(Gas Gauging)]
Dsg Current Threshold = 100
Chg Current Threshold = 50
Quit Current = 10
[State(Gas Gauging)]
Qmax Cell 0 = 3190
Qmax Cell 1 = 3208
Qmax Cell 2 = 3189
Qmax Cell 3 = 3100
Qmax Pack = 3189
Update Status = 06
Cell 0 Chg dod at EoC = 1352
Cell 1 Chg dod at EoC = 0
Cell 2 Chg dod at EoC = 1312
Cell 3 Chg dod at EoC = 0
Avg I Last Run = -1454
Avg P Last Run = -1615
Delta Voltage = 15
Max Avg I Last Run = -1457
Max Avg P Last Run = -1799
[R_a0(Ra Table)]
Cell0 R_a flag = 0555
Cell0 R_a 0 = 61
Cell0 R_a 1 = 71
Cell0 R_a 2 = 94
Cell0 R_a 3 = 133
Cell0 R_a 4 = 155
Cell0 R_a 5 = 101
Cell0 R_a 6 = 120
Cell0 R_a 7 = 145
Cell0 R_a 8 = 136
Cell0 R_a 9 = 142
Cell0 R_a 10 = 153
Cell0 R_a 11 = 171
Cell0 R_a 12 = 256
Cell0 R_a 13 = 601
Cell0 R_a 14 = 20954
[R_a1(Ra Table)]
Cell1 R_a flag = 0555
Cell1 R_a 0 = 58
Cell1 R_a 1 = 67
Cell1 R_a 2 = 87
Cell1 R_a 3 = 121
Cell1 R_a 4 = 140
Cell1 R_a 5 = 91
Cell1 R_a 6 = 106
Cell1 R_a 7 = 127
Cell1 R_a 8 = 119
Cell1 R_a 9 = 126
Cell1 R_a 10 = 137
Cell1 R_a 11 = 152
Cell1 R_a 12 = 233
Cell1 R_a 13 = 545
Cell1 R_a 14 = 19076
[R_a2(Ra Table)]
Cell2 R_a flag = 0555
Cell2 R_a 0 = 61
Cell2 R_a 1 = 70
Cell2 R_a 2 = 92
Cell2 R_a 3 = 129
Cell2 R_a 4 = 152
Cell2 R_a 5 = 100
Cell2 R_a 6 = 117
Cell2 R_a 7 = 142
Cell2 R_a 8 = 134
Cell2 R_a 9 = 140
Cell2 R_a 10 = 150
Cell2 R_a 11 = 170
Cell2 R_a 12 = 256
Cell2 R_a 13 = 597
Cell2 R_a 14 = 20834
[R_a3(Ra Table)]
Cell3 R_a flag = FF55
Cell3 R_a 0 = 45
Cell3 R_a 1 = 52
Cell3 R_a 2 = 58
Cell3 R_a 3 = 76
Cell3 R_a 4 = 88
Cell3 R_a 5 = 52
Cell3 R_a 6 = 58
Cell3 R_a 7 = 65
Cell3 R_a 8 = 57
Cell3 R_a 9 = 58
Cell3 R_a 10 = 62
Cell3 R_a 11 = 69
Cell3 R_a 12 = 105
Cell3 R_a 13 = 261
Cell3 R_a 14 = 9119
[R_a0x(Ra Table)]
xCell0 R_a flag = FFFF
xCell0 R_a 0 = 45
xCell0 R_a 1 = 52
xCell0 R_a 2 = 58
xCell0 R_a 3 = 76
xCell0 R_a 4 = 88
xCell0 R_a 5 = 52
xCell0 R_a 6 = 58
xCell0 R_a 7 = 65
xCell0 R_a 8 = 57
xCell0 R_a 9 = 58
xCell0 R_a 10 = 62
xCell0 R_a 11 = 69
xCell0 R_a 12 = 105
xCell0 R_a 13 = 261
xCell0 R_a 14 = 9119
[R_a1x(Ra Table)]
xCell1 R_a flag = FFFF
xCell1 R_a 0 = 45
xCell1 R_a 1 = 52
xCell1 R_a 2 = 58
xCell1 R_a 3 = 76
xCell1 R_a 4 = 88
xCell1 R_a 5 = 52
xCell1 R_a 6 = 58
xCell1 R_a 7 = 65
xCell1 R_a 8 = 57
xCell1 R_a 9 = 58
xCell1 R_a 10 = 62
xCell1 R_a 11 = 69
xCell1 R_a 12 = 105
xCell1 R_a 13 = 261
xCell1 R_a 14 = 9119
[R_a2x(Ra Table)]
xCell2 R_a flag = FFFF
xCell2 R_a 0 = 45
xCell2 R_a 1 = 52
xCell2 R_a 2 = 58
xCell2 R_a 3 = 76
xCell2 R_a 4 = 88
xCell2 R_a 5 = 52
xCell2 R_a 6 = 58
xCell2 R_a 7 = 65
xCell2 R_a 8 = 57
xCell2 R_a 9 = 58
xCell2 R_a 10 = 62
xCell2 R_a 11 = 69
xCell2 R_a 12 = 105
xCell2 R_a 13 = 261
xCell2 R_a 14 = 9119
[R_a3x(Ra Table)]
xCell3 R_a flag = FFFF
xCell3 R_a 0 = 45
xCell3 R_a 1 = 52
xCell3 R_a 2 = 58
xCell3 R_a 3 = 76
xCell3 R_a 4 = 88
xCell3 R_a 5 = 52
xCell3 R_a 6 = 58
xCell3 R_a 7 = 65
xCell3 R_a 8 = 57
xCell3 R_a 9 = 58
xCell3 R_a 10 = 62
xCell3 R_a 11 = 69
xCell3 R_a 12 = 105
xCell3 R_a 13 = 261
xCell3 R_a 14 = 9119
[Device Status Data(PF Status)]
Saved PF Flags 1 = 0000
Saved PF Flags 2 = 0000
Saved 1st PF Flags 1 = 0000
Saved 1st PF Flags 2 = 0000
[Data(Calibration)]
CC Gain = 10.057
CC Delta = 10.057
Ref Voltage = 1225.85
AFE Pack Gain = 792.24
CC Offset = -0.226
Board Offset = -26.9
Int Temp Offset = 0.0
Ext1 Temp Offset = -.2
Ext2 Temp Offset = 0.0
[Config(Calibration)]
CC Current = 3000
Voltage Signal = 13050
Temp Signal = 298.0
CC Offset Time = 250
ADC Offset Time = 32
CC Gain Time = 250
Voltage Time = 1888
Temperature Time = 32
Cal Mode Timeout = 300
[Temp Model(Calibration)]
Ext Coef 1 = -28529
Ext Coef 2 = 20773
Ext Coef 3 = -7043
Ext Coef 4 = 389.7
Ext Min AD = 0
Ext Max Temp = 389.7
Int Coef 1 = 0
Int Coef 2 = 0
Int Coef 3 = -11136
Int Coef 4 = 575.4
Int Min AD = 0
Int Max Temp = 575.4
[Current(Calibration)]
Filter = 239
Deadband = 3
CC Deadband = 10.0