BQ27421EVM-G1A: bqStudio calibration issue.

I forgot to add picture

Hello Bartosz,

Make sure that the charger can satisfy valid charge termination conditions. FC bit should be set at this point.

Until then charging is not complete.

Hello Shirish,
Charger can charge battery to 4200mV. I try to connect bench supply and increase voltage to 4300mV but it do not help.

If I remember it right - FC bit is set automatically so I can't control it. So what I should do more? When I use D type fuel gauge on that setup with that battery it work but it shouldn't - charged voltage for D type is 4400mV but maximum charge voltage for my battery is 4200mV. Now I using A type and it stucks on that charging  procedure.

Hello Bartosz,

Did you check if your battery is compatible with BQ27421EVM-G1A? Use the GPCCHEM tool if you haven't checked compatibility

Hello Shirich,
Do the gpchem is not the older version of bqstudio? Going to that website I can find link to bqStudio: https://www.ti.com/tool/GPCCHEM#description.
I'm trying make that processes to obtain that data and check the battery compability but as I said it stuck on charging process. Or should I make it fully manual?

The gauge needs to be configured to detect charge termination. bqStudio requires that this step is done before you can run a learning cycle. Besides checking compatibility of chemistry via GPC, please also make sure that you configured the gauge correctly for your charging setup. See the Quick Start Guide how to configure Taper Rate. https://www.ti.com/lit/pdf/sluuah7

GPCCHEM doesn't depend on bqStudio. You can use bqStudio to log current, voltage and temperature (using Register Log) and then you can go through a relax/charge/discharge/relax cycle as explained in the user's guide for GPCCHEM. This is not a learning cycle (but looks similar). For a learning cycle, you first should make sure that the chemistry is compatible and then you have to configure the gauge to detect charge termination, otherwise the bqStudio learning cycle state machine gets stuck in charging state (which is not an error by the GUI but a user error).

Hello Dominiki,
Before automatic learning cycle I make propoer fuel gauge configuration. 
it take some time but I have result from GPCCHEM tool too. What should I do next? I want to make calibration process because I have some big issues with SOC stability reading.

Here I put the GPCCHEM result:

Chemistry ID selection tool, rev=2.54		
		
Configuration used in present fit:		
ProcessingType = 2		
NumCellSeries = 1		
ElapsedTimeColumn=0		
VoltageColumn = 2		
CurrentColumn = 3		
TemperatureColumn = 1		
		
Best chemical ID : 1255	Best chemical ID max. deviation, % : 1.76	
		
		
		
Summary of all IDs with max. DOD deviation below 3%		
		
Chem ID	max DOD error, %	Max R deviation, ratio
1255	1.76	0.25
1857	1.91	0.44
105	1.97	0.59
1118	2.08	0.25
3230	2.17	0.18
1339	2.18	0.41
1189	2.26	0.26
1296	2.3	0.2
3547	2.35	0.2
533	2.36	0.14
1148	2.39	0.38
1297	2.45	0.36
1312	2.5	0.22
1188	2.5	0.59
1121	2.53	0.4
1178	2.56	0.25
2105	2.59	0.4
1271	2.6	0.44
1313	2.6	0.19
1559	2.61	0.77
2489	2.61	0.27
152	2.62	0.57
1288	2.66	0.25
354	2.68	0.42
1210	2.72	0.34
1139	2.73	0.39
3771	2.73	0.24
1347	2.78	0.21
1381	2.78	0.52
2032	2.84	0.98
2063	2.85	0.83
1167	2.88	0.29
3731	2.96	0.23
1143	3	0.19
		
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	2.68
3142	bq27421-G1D: 4.4V LiCoO2	7.53
128	bq27421-G1A: 4.2V LiCoO2	13.29
312	bq27421-G1B: 4.3V LiCoO2	19.17
Best generic ID 354		
Max. deviations for best generic ID is within recommended range. Please chose this ID in your device configuration or device family.		
		
		
Device / Family #2		
Generic Chem ID	Device/ Voltage/ Chemistry	max DOD error, %
354	bq27621:  (ALT_CHEM2) 4.35V LiCoO2	2.68
1210	bq27621:  (ALT_CHEM1) 4.3V LiCoO2	2.72
1202	bq27621: (default) 4.2V LiCoO2	5.85
Best generic ID 354		
Max. deviations for best generic ID is within recommended range. Please chose this ID in your device configuration or device family.		
		
		
Device / Family #3		
Generic Chem ID	Device/ Voltage/ Chemistry	max DOD error, %
3230	bq27426: (default) 4.35V LiCoO2	2.17
1202	bq27426: (ALT_CHEM1) 4.2V LiCoO2	5.85
3142	bq27426: (ALT-CHEM2) 4.4V LiCoO2	7.53
Best generic ID 3230		
Max. deviations for best generic ID is within recommended range. Please chose this ID in your device configuration or device family.		
		
		

Best regards,

Bartosz

Hello Shirish, so I understood I need to change fuel gauge - I can't change CHEM_ID in bq27421? So please explain to me why one of your engineer in ticket CS1670656 said that changing CHEM_ID procedure in bq27421 is the same as in bq27426?
Best regards,

Bartosz

e2e.ti.com/.../bq27426-program-chem-id

Hello Shirish,
do you think I can use BQ274727? It is pin compatible with bq27421 fuel gauge and have 3230  CHEM_ID. On report file I can find information that CHEM_ID 3230 have only 2.17% error.

3230 bq27426: (default) 4.35V LiCoO2 2.17

Best regards,

Bartosz