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BQ27411-G1: BQ27441: wrong values of SOC

Lakhal Mohammed
Prodigy 175 points
Part Number: BQ27411-G1
Other Parts Discussed in Thread: BQSTUDIO, GPCCHEM, BQ27Z561

Hey

if the battery is in discharge , the read percentage value (SOC) is not accurate. So to read the correct percentage values we have to make RESET each time. The following picture shows the results of a test showing this problem.

For the picture, the values are read every 4 seconds. And to discharge the battery quickly we have added a 220 Ohm . 

The data log is attached. Discharge G1-A.txt

  • 0
    TI__Guru 52115 points

    Hi Lakhal,

    Have you ever used the GPCHEM tool (http://www.ti.com/tool/GPCCHEM) to check whether the preprogrammed chemistry id is a good match for your battery cell?

    Andy

  • 0 in reply to Andy Liu (BMS)
    Prodigy 175 points

    Hi 

    Thanks for your feedback,

    i don't have Ti bqstudio or Ti EVm software to generate the configuration file.

    We are using BQ27441 G1-A,  Chem iD= 0x0128. and Battery Li-Poly 1000 mAh  ( Datasheet attached). Do you think we are using the good chemistry id?

    Thank youDataSheet-LP402764-1000ZHL.pdf

  • 0 in reply to Lakhal Mohammed
    TI__Mastermind 24870 points

    Hello Lakhal,

    The best way is to use GPCCHEM to find the ideal match. Can you run the test using a TI EVM and bqStudio?

  • 0
    Prodigy 175 points

    Hello

    I did the test, here is the results, Which Fuel gauge do you recommand us please?

    Can we continue using the BQ27441 G1-A ? if yes how can we resolve the problem of disconnecting and connecting the battery?

    2210.GPC_report.txt 
    Chemistry ID selection tool, rev=2.49		
		
Configuration used in present fit:		
ProcessingType = 2		
NumCellSeries = 1		
ElapsedTimeColumn = 0		
VoltageColumn = 1		
CurrentColumn = 2		
TemperatureColumn = 3		
		
Best chemical ID : 2102	Best chemical ID max. deviation, % : 1.88	
		
		
		
Summary of all IDs with max. DOD deviation below 3%		
		
Chem ID	max DOD error, %	Max R deviation, ratio
2102	1.88	0.2
2077	2.02	0.32
255	2.04	0.65
1996	2.09	0.59
2682	2.17	0.39
2051	2.18	0.58
2605	2.21	0.25
200	2.22	1.02
203	2.22	1.02
208	2.22	1.02
212	2.27	0.64
3385	2.3	1.12
264	2.31	0.71
2066	2.34	0.18
239	2.42	0.34
1280	2.42	0.58
2023	2.48	0.63
2041	2.53	1.8
2025	2.55	0.33
2590	2.58	0.35
234	2.59	0.24
1594	2.6	0.38
2078	2.65	1.06
2082	2.76	0.25
		
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, %
3142	bq27421-G1D: 4.4V LiCoO2	14.34
354	bq27411-G1C: 4.35V LiCoO2	14.58
128	bq27421-G1A: 4.2V LiCoO2	32.63
312	bq27421-G1B: 4.3V LiCoO2	44.86
Best generic ID 3142		
Warning: Deviation for best generic ID is above recommended level for this device / family. Consider using another device, flash based gauge or RAM programming of custom ID.		
		
		
Device / Family #2		
Generic Chem ID	Device/ Voltage/ Chemistry	max DOD error, %
1210	bq27621:  (ALT_CHEM1) 4.3V LiCoO2	13.26
354	bq27621:  (ALT_CHEM2) 4.35V LiCoO2	14.58
1202	bq27621: (default) 4.2V LiCoO2	17.85
Best generic ID 1210		
Warning: Deviation for best generic ID is above recommended level for this device / family. Consider using another device, flash based gauge or RAM programming of custom ID.		
		
		
Device / Family #3		
Generic Chem ID	Device/ Voltage/ Chemistry	max DOD error, %
3230	bq27426: (default) 4.35V LiCoO2	13.74
3142	bq27426: (ALT-CHEM2) 4.4V LiCoO2	14.34
1202	bq27426: (ALT_CHEM1) 4.2V LiCoO2	17.85
Best generic ID 3230		
Warning: Deviation for best generic ID is above recommended level for this device / family. Consider using another device, flash based gauge or RAM programming of custom ID.
    4111.MiscInfo.txt 
    ProcessingType= 2

  • 0 in reply to Lakhal Mohammed
    TI__Mastermind 24870 points

    Hello Lakhal,

    Can you look at the bq27z561?

    The best way to resolve is with a flash based gauge. It's contents will not be cleared upon a POR. Also it will be more flexible with flash based chemistry programming.

  • 0 in reply to Kang Kang
    Prodigy 175 points

    Hi,

    thank you for your quick reply

    where can i find more informations about ' flash based gauge' ,?

    Can i do that with BQ27441 G1-A or i must to do it with BQ27z561?

  • 0
    Prodigy 175 points

    Hey

    I have changed the wording of my question by adding some elements that may be useful.
    Thank you for your feedback, we look forward to hearing from you.

    Thanks

  • 0 in reply to Lakhal Mohammed
    TI__Guru 52115 points

    See our answers in the new thread. I will close this thread.

    Andy