Hi
I am trying to get the BQ34Z110 optimised for a 12V 1.2Ah lead acid battery. I have followed the "Design Steps" instructions on the datasheet to the letter several times but I am still getting problems with the Gas guage.
The circuit I have implemented has a relay in series with the load. I am discharging the battery with a load current of 126mAh. When the battery voltage gets to 6.5V the relay opens and the load is disconnected. The quiescent current of the relay circuit when the relay is opened is 19mA.
The data RAM "NomAvailCAP" and the "Full Available Capacity" start at 1200mAh. I have calibrated the discharge current and the battery voltage very accurately. When I start discharging at 126mAh the guage records this accurately. However due to the length of time it takes to discharge the battery I have to rely on a circuit to operate in my absence to disconnect the load. This period of time that I am absent is normally 15 Hours overnight and I estimate that the relay opens the load approximately 4 hours before I start re-charging the battery.
I have not had any issues until recently and I have always seen the OCVTAKEN flag set, and the VOK flag cleared when I check the DataRAM in the morning. As soon as I start to charge the battery the VOK flag changes to set (Red).This system worked fine and I successfully ran two optimisation cycles and the guage appeared to be working correctly. However on subsequent runs of this system the "NomAvailCAP" and the "Full Available Capacity" changed to 289mAh. When I recharge the battery the gas guage "NomAvailCAP" value increases to 289mAh and then stops even though the average current value that the battery is charging at shows 900mA.
On a separate issue I have noticed that if I allow the gas guage to go into sleep mode when I start discharging at 126mAh the gas guage does not always exit sleep mode. If I disconnect the load and then reconnect the load the Gas guage will then come out of sleep mode.
My Questions are:-
1. Why is the "NomAvailCAP" and the "Full Available Capacity" starting at 1200mAh but changing to 289mAh when the discharge load current changes from 126mAh to 19mAh overnight. The time that the discharge current is 19mAh is around 4 - 6 Hours and the change is due to a relay circuit disconnecting the load. The 19mA discharge is the quiescent current of the relay circuit
2. Why does the Gas Guage continue to think that the battery charge is full even though there is a current flowing into the battery of 271mA at a battery voltage of 13392V. I would expect the "NomAvailCAP" and the "Full Available Capacity" to increase as there is still current flowing into the battery.
3. Why doe the gas guage not "Wake Up" from sleep mode when the battery is being discharged at 126mAh.
4. What does ChgDoDEoC mean. Not all of the acronyms used in the datasheet are explained.
5. I would like to optimise a 1.2Ah battery 12V Sealed Lead Acid battery which will drive a circuit with a quiescent standby current of 20mA but with intermitttant loads of up to 1A for a maximum of 30 seconds. Can you please check my GG file and make sure that this is correct??
6. What is the SENC file it does not explain this anywhere in the datasheet.
7. If and When I have got the battery optimised what files do I need to save in order to copy this information across to production gas guages. Do I need to save the SENC file and the GG file and reload both into a production gas guage or do I just need to load the GG file.
8. What is the Ra table and what do the numbers in it mean??
I would be grateful if you could help me with the above as optimisation of the gas guage and battery takes a long time and it is becoming increasingly frustrating as it appears not to work.
[Header]
bq EVSW Version = 0.9.90
DeviceName = bq34z110 v0.04
Time = 15/05/2013 14:00:17
[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
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 = 100
Min Taper Capacity = 25
Cell Taper Voltage = 100
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
Design Cell Voltage = 2000
Initial Standby = -10
Initial MaxLoad = -500
Manuf Date = 01-Jan-1980
Ser. Num. = 0001
Cycle Count = 2
CC Threshold = 900
Design Cell Capacity = 1200
Design Cell Energy = 14400
SOH Load I = -400
TDD SOH Percent = 90
Cell Charge Voltage T1-T2 = 2400
Cell Charge Voltage T2-T3 = 2400
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 = 175
SOC1 Clear Threshold = 200
SOCF Set Threshold = 75
SOCF Clear Threshold = 100
Cell BL Set Volt Threshold = 1166
Cell BL Set Volt Time = 2
Cell BL Clear Volt Threshold = 1850
Cell BH Set Volt Threshold = 2300
Cell BH Volt Time = 2
Cell BH Clear Volt Threshold = 2200
[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 = 66CA
[Lifetime Data(Configuration)]
Lifetime Max Temp = 30.0
Lifetime Min Temp = 20.0
Lifetime Max Chg Current = 1697
Lifetime Max Dsg Current = -721
Lifetime Max Pack Voltage = 14484
Lifetime Min Pack Voltage = 6558
[Lifetime Temp Samples(Configuration)]
LT Flash Cnt = 113
[Registers(Configuration)]
Pack Configuration = 0961
Pack Configuration B = A9
Pack Configuration C = 30
LED_Comm Configuration = 9B
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 = 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 = 100
Cell Terminate Voltage = 1000
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 = 697
Cycle Count = 0
Update Status = 00
Cell V at Chg Term = 2406
Avg I Last Run = -299
Avg P Last Run = -1131
Cell Delta Voltage = 2
T Rise = 0
T Time Constant = 32767
[OCVa Table(OCV Table)]
Chem ID = 0800
[R_a0(Ra Table)]
Cell0 R_a flag = FF55
Cell0 R_a 0 = 429
Cell0 R_a 1 = 378
Cell0 R_a 2 = 356
Cell0 R_a 3 = 338
Cell0 R_a 4 = 328
Cell0 R_a 5 = 312
Cell0 R_a 6 = 321
Cell0 R_a 7 = 383
Cell0 R_a 8 = 401
Cell0 R_a 9 = 403
Cell0 R_a 10 = 467
Cell0 R_a 11 = 493
Cell0 R_a 12 = 643
Cell0 R_a 13 = 838
Cell0 R_a 14 = 1033
[R_a0x(Ra Table)]
xCell0 R_a flag = FFFF
xCell0 R_a 0 = 429
xCell0 R_a 1 = 378
xCell0 R_a 2 = 356
xCell0 R_a 3 = 338
xCell0 R_a 4 = 328
xCell0 R_a 5 = 312
xCell0 R_a 6 = 321
xCell0 R_a 7 = 383
xCell0 R_a 8 = 401
xCell0 R_a 9 = 403
xCell0 R_a 10 = 467
xCell0 R_a 11 = 493
xCell0 R_a 12 = 643
xCell0 R_a 13 = 838
xCell0 R_a 14 = 1033
[Data(Calibration)]
CC Gain = 10.122
CC Delta = 10.102
CC Offset = -0.68
Board Offset = -0.33
Int Temp Offset = 0.0
Ext Temp Offset = 0.0
Voltage Divider = 19190
[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
Kind Regards
David Brown.