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BQ27441-G1: Choosing G1A or G1B

Adam Johnson
Expert 1310 points
Part Number: BQ27441-G1
Other Parts Discussed in Thread: TPS65721, , MSP430FR5869, BQ27441EVM-G1A, BQSTUDIO, GPCCHEM, BQ27426

I am working on a battery-powered design using the MSP430FR5869 controller (FRAM is awesome!) along with the TPS65721 Battery Charger/Regulator.  I would like to use the BQ27441-G1 as a fuel gauge, but am not sure if it will work with my battery.

I understand that there are two versions of the BQ27441-G1, for two common battery chemistries.  The quick-start guide says, "The bq27441-G1A should be used if the cathode is a traditional LiCoO2 chemistry and/or the battery data sheet recommends a maximum charging voltage of 4.2 V. The bq27441- G1B should be selected if the cathode is a lithium-manganese type and/or the maximum recommended charging voltage is 4.3 V or 4.35 V. These two types of rechargeable lithium chemistries are the most popular in the industry and other types are not currently supported by the bq27441."

My battery's datasheet (attached) does not specify the chemistry, but lists the charge voltage as 4.2V.  Does that mean its chemistry is compatible with the G1A?

Thank you,

Adam J.

GMB503448-900mAh(with PCM)A0.pdf

  • 0
    TI__Guru* 76230 points

    Hello Adam.

    Pls use our tool and run the tests described in the link to determine if the bq27741-G1A would be a good fit for your battery. it will email you a report letting you know if it is a got fit. If you don't have the time to run the test, then i would recommend using our bq27520-G3 as that will work with any chemistry as you have the ability to program a chem id that matches your cell.

  • 0 in reply to Onyx Ahiakwo
    Expert 1310 points
    You meant to type "BQ27441-G1A," yes?
  • 0 in reply to Onyx Ahiakwo
    Expert 1310 points

    Onyx,

    I used the BQ27GDK000EVM along with a BQ27441EVM-G1A to perform a Rel-Dis-Rel Cycle.  On the BQ27441EVM-G1A, I added a 10k resistor from the BIN pin to tthe PACK- pin.  On bqStudio, I set the following settings:

    • Begin each cycle with charge task.
    • Repeat cycle exactly 1 time.
    • Charge voltage 4200 mV.
    • Charge current 550 mA.
    • Charge termination when taper current = 55 mA.
    • Relax after charge for 120 min.
    • Discharge at constant current of 110 mA.
    • Discharge cutoff at 2800 mV.
    • Terminate discharge at 3000 mV.
    • Relax after discharge for 300 min.

    The test took a long time, so I left it unattended overnight.  However, when the battery voltage dropped to 3.0 V, the fuel gauge powered off.  So I did not get any data from the five-hour relax after discharge.  Also, when I checked my test setup this morning, the battery voltage was at 0.916 V!  I've attached the .log file from bqStudio.  Please find the battery datasheet from original post in this thread.

    So here are my questions:

    • Can I use the BQ27GDK000EVM to trickle-charge my battery back to a healthy voltage?  bqStudio gives an error when I try to charge because it wants to talk to the fuel gauge first.
    • Are some of my settings wrong?  What did I do to cause the battery to over-discharge?
    • It took over ten hours to discharge the battery at C/10 discharge (110 mA).  Can I set a higher discharge rate?  What's a good rule of thumb for how much current to discharge at?

    Thank you,

    Adam J.

    RelDisRel1100mAh.log

  • 0 in reply to Adam Johnson
    TI__Guru* 76230 points
    I have had problems in the past when discharging with really small current like you are trying to do.You wil need to increase that current to c/5

    -Setting your discharge cuttoff is set to 2800 could perhaps have could be the cause of your over-discharge.
    -A value between c/5 and c/10 is good. I recommend using c/7

    thanks
    Onyx
  • 0 in reply to Onyx Ahiakwo
    Expert 1310 points
    I resolved my discharge issue by choosing a discharge current of slightly less than C/10, which gave a discharge time of just over 10 hours. In practice it looked like a rate of exactly C/10 gave a discharge rate a bit less than 10 hours, which causes complaints in the GPCCHEM tool mentioned above.

    Adam J.
  • 0 in reply to Adam Johnson
    Expert 1310 points

    I performed the rel-dis-rel cycle four more times, on two batteries that I'm considering for use in my system.  One is 890 mAh, and the other is 1100 mAh.  (Datasheets are attached, as well as the chemistry reports from TI).

    I would like to use a RAM-based gauge (to reduce the development time).  Further, I presume I should choose among the gauges for a 4.2V battery, since that is the max charging voltage on the batteries' datasheets. According to the chemistry reports (attached) the recommended RAM-based fuel gauges for a 4.2V battery are bq27421-G1A, bq27621 and bq27426.  The bq27426 and bq27621 have Chem ID 1202, bq27421-G1A has Chem ID 0128.

    However, the bq27441-G1A also has Chem ID 0128.  Does that mean it is also a good choice for my batteries?  Also, Chem ID 0128 and 1202 both seem very widely used among TI's RAM-based gauges for 4.2V batteries.  Is there some defining difference between them that might help me pick between them for my batteries?  Is one more generic or something?

    Thank you,

    Adam J.

    6663.GMB503448-900mAh(with PCM)A0.pdf

    GMB503759.pdf

    Fullscreen 890mAhBattery85mADischarge-report.txt Download 
    Chemistry ID selection tool, rev=2.24		
		
Configuration used in present fit:		
ProcessingType=2		
NumCellSeries=1		
ElapsedTimeColumn=0		
VoltageColumn=2		
CurrentColumn=3		
TemperatureColumn=1		
		
Best chemical ID : 1114	Best chemical ID max. deviation, % : 1.54	
		
		
		
Summary of all IDs with max. DOD deviation below 3%		
		
Chem ID	max DOD error, %	Max R deviation, ratio
1114	1.54	0.53
3169	1.66	0.6
1384	1.94	0.44
2109	1.98	0.46
3757	1.98	0.46
0320	2.10	1.75
0105	2.22	0.59
0316	2.25	1.37
1119	2.32	0.94
1496	2.35	0.89
1503	2.35	0.89
1141	2.35	0.64
1322	2.35	0.29
0177	2.37	1.32
0158	2.38	0.42
0139	2.40	0.7
0193	2.40	0.97
0174	2.41	0.48
0173	2.50	0.35
1218	2.52	1.52
1365	2.52	0.82
0154	2.54	0.43
1194	2.55	1.64
1162	2.58	0.84
1132	2.62	0.78
1269	2.62	0.61
3139	2.64	0.42
1208	2.64	0.48
1369	2.65	0.55
1367	2.65	0.92
1597	2.65	0.56
1130	2.66	0.56
0143	2.68	0.65
0366	2.72	0.54
1210	2.74	0.87
0152	2.80	0.57
1129	2.80	1.17
1326	2.81	0.79
3519	2.81	0.79
0181	2.82	0.92
1142	2.84	0.92
1337	2.84	0.61
1339	2.85	0.89
1341	2.87	0.74
0178	2.87	0.67
1336	2.87	0.4
0183	2.90	0.76
1310	2.91	0.66
1342	2.92	0.77
0172	2.92	0.38
1239	2.93	0.77
0133	2.93	0.41
1271	2.95	1.85
3684	2.97	0.98
3610	2.97	1.04
1118	2.98	1.15
0391	2.99	0.66
		
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	1.88
0354	bq27411-G1C: 4.35V LiCoO2	3.54
0312	bq27421-G1B: 4.3V LiCoO2	5.03
0128	bq27421-G1A: 4.2V LiCoO2	5.93
Best generic ID 3142		
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, %
1210	bq27621:  (ALT_CHEM1) 4.3V LiCoO2	2.74
1202	bq27621:  (default) 4.2V LiCoO2		3.41
0354	bq27621:  (ALT_CHEM2) 4.35V LiCoO2	3.54
Best generic ID 1210		
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, %
3142	bq27426: (ALT-CHEM2) 4.4V LiCoO2	1.88
3230	bq27426: (default) 4.35V LiCoO2	2.56
1202	bq27426: (ALT_CHEM1) 4.2V LiCoO2	3.41
Best generic ID 3142		
Max. deviations for best generic ID is within recommended range. Please chose this ID in your device configuration or device family.

    Fullscreen 890mAhBattery89mADischarge-report.txt Download 
    Chemistry ID selection tool, rev=2.24		
		
Configuration used in present fit:		
ProcessingType=2		
NumCellSeries=1		
ElapsedTimeColumn=0		
VoltageColumn=2		
CurrentColumn=3		
TemperatureColumn=1		
		
Best chemical ID : 1114	Best chemical ID max. deviation, % : 1.7	
		
		
		
Summary of all IDs with max. DOD deviation below 3%		
		
Chem ID	max DOD error, %	Max R deviation, ratio
1114	1.70	1.05
3169	1.83	0.68
3757	2.13	0.38
2109	2.20	0.39
0105	2.38	1.06
1496	2.53	0.94
1503	2.53	0.94
3684	2.62	1.28
1597	2.66	0.5
1239	2.66	0.67
1210	2.67	1.33
1119	2.70	1.56
1326	2.72	1.07
3519	2.72	1.07
0366	2.72	0.52
1130	2.75	1.14
1269	2.77	0.8
0181	2.80	1.27
0139	2.82	0.56
1118	2.84	1.16
0177	2.90	1.78
0133	2.90	0.28
1341	2.92	0.66
0391	2.92	0.88
1129	2.94	1.37
0183	2.95	0.68
3610	2.96	1.32
0178	2.97	0.83
0152	2.98	0.56
1271	2.99	1.87
1339	2.99	0.94
1342	3.00	0.67
0158	3.00	0.82
		
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	3.29
0354	bq27411-G1C: 4.35V LiCoO2	3.61
0312	bq27421-G1B: 4.3V LiCoO2	5.66
0128	bq27421-G1A: 4.2V LiCoO2	5.78
Best generic ID 3142		
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, %
1210	bq27621:  (ALT_CHEM1) 4.3V LiCoO2	2.67
1202	bq27621:  (default) 4.2V LiCoO2		3.34
0354	bq27621:  (ALT_CHEM2) 4.35V LiCoO2	3.61
Best generic ID 1210		
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		2.68
3142	bq27426: (ALT-CHEM2) 4.4V LiCoO2	3.29
1202	bq27426: (ALT_CHEM1) 4.2V LiCoO2	3.34
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.

    Fullscreen 1100mAhBattery95mADischarge-report.txt Download 
    Chemistry ID selection tool, rev=2.24		
		
Configuration used in present fit:		
ProcessingType=2		
NumCellSeries=1		
ElapsedTimeColumn=0		
VoltageColumn=2		
CurrentColumn=3		
TemperatureColumn=1		
		
Best chemical ID : 1208	Best chemical ID max. deviation, % : 1.85	
		
		
		
Summary of all IDs with max. DOD deviation below 3%		
		
Chem ID	max DOD error, %	Max R deviation, ratio
1208	1.85	0.18
1119	1.89	0.54
1336	2.11	0.56
0172	2.13	0.16
1114	2.16	0.5
1229	2.19	0.48
0177	2.24	0.6
3757	2.25	0.84
1236	2.29	0.65
0133	2.29	0.11
1111	2.35	0.59
1337	2.36	0.54
0105	2.37	0.62
2109	2.42	0.86
0158	2.43	0.19
1326	2.46	0.34
3519	2.46	0.34
1271	2.50	0.31
1339	2.53	0.48
1384	2.53	0.58
1297	2.56	0.92
1565	2.59	0.32
1122	2.62	0.57
1132	2.66	0.5
1148	2.67	0.48
1181	2.72	0.37
1255	2.79	1.07
0173	2.81	0.3
1302	2.83	0.57
1252	2.84	0.4
1334	2.85	0.41
2015	2.88	0.62
0174	2.88	0.3
1202	2.92	0.43
1139	2.95	0.62
1203	2.97	0.31
1333	2.98	1.07
0181	2.98	0.34
		
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, %
0354	bq27411-G1C: 4.35V LiCoO2	2.88
3142	bq27421-G1D: 4.4V LiCoO2	3.84
0128	bq27421-G1A: 4.2V LiCoO2	5.33
0312	bq27421-G1B: 4.3V LiCoO2	9.62
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, %
1210	bq27621:  (ALT_CHEM1) 4.3V LiCoO2	2.17
0354	bq27621:  (ALT_CHEM2) 4.35V LiCoO2	2.88
1202	bq27621:  (default) 4.2V LiCoO2		2.92
Best generic ID 1210		
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, %
1202	bq27426: (ALT_CHEM1) 4.2V LiCoO2	2.92
3230	bq27426: (default) 4.35V LiCoO2	3.61
3142	bq27426: (ALT-CHEM2) 4.4V LiCoO2	3.84
Best generic ID 1202		
Max. deviations for best generic ID is within recommended range. Please chose this ID in your device configuration or device family.

    Fullscreen 1100mAhBattery100mADischarge-report.txt Download 
    Chemistry ID selection tool, rev=2.24		
		
Configuration used in present fit:		
ProcessingType=2		
NumCellSeries=1		
ElapsedTimeColumn=0		
VoltageColumn=2		
CurrentColumn=3		
TemperatureColumn=1		
		
Best chemical ID : 1119	Best chemical ID max. deviation, % : 1.42	
		
		
		
Summary of all IDs with max. DOD deviation below 3%		
		
Chem ID	max DOD error, %	Max R deviation, ratio
1119	1.42	0.55
1114	1.63	0.22
0133	1.77	0.06
1208	1.86	0.15
1339	1.95	0.63
1111	1.95	0.59
1181	2.07	0.35
1271	2.12	0.45
3757	2.12	0.56
1337	2.17	0.53
0172	2.18	0.13
1229	2.19	0.6
1148	2.20	0.63
0158	2.27	0.11
1336	2.27	0.49
1132	2.34	0.44
0177	2.38	0.52
1168	2.42	0.44
1236	2.44	0.82
2109	2.47	0.6
1169	2.48	0.47
1565	2.49	0.25
1202	2.51	0.34
1141	2.51	0.41
1255	2.51	0.97
1297	2.58	1.01
0174	2.58	0.23
1334	2.60	0.33
1286	2.61	0.59
1139	2.65	0.67
0181	2.65	0.33
0105	2.66	0.31
1335	2.66	0.33
1322	2.68	0.38
1203	2.70	0.4
1194	2.75	0.83
1326	2.76	0.34
3519	2.76	0.34
1384	2.76	0.51
0139	2.77	0.27
1252	2.79	0.29
1338	2.82	0.13
1302	2.84	0.5
0193	2.87	0.31
1211	2.88	0.6
1597	2.88	0.37
3511	2.93	0.73
0173	2.93	0.27
0196	2.94	0.53
		
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, %
0354	bq27411-G1C: 4.35V LiCoO2	2.52
3142	bq27421-G1D: 4.4V LiCoO2	4.04
0128	bq27421-G1A: 4.2V LiCoO2	5.76
0312	bq27421-G1B: 4.3V LiCoO2	11.13
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, %
1210	bq27621:  (ALT_CHEM1) 4.3V LiCoO2	1.91
1202	bq27621:  (default) 4.2V LiCoO2		2.51
0354	bq27621:  (ALT_CHEM2) 4.35V LiCoO2	2.52
Best generic ID 1210		
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, %
1202	bq27426: (ALT_CHEM1) 4.2V LiCoO2	2.51
3230	bq27426: (default) 4.35V LiCoO2		3.82
3142	bq27426: (ALT-CHEM2) 4.4V LiCoO2	4.04
Best generic ID 1202		
Max. deviations for best generic ID is within recommended range. Please chose this ID in your device configuration or device family.

  • 0 in reply to Adam Johnson
    TI__Guru* 76230 points
    H Adam,
    Your batteries chem ids fall within the 5% DOD error range for ROM gauges so technically any one of the chem ids would work. The lesser the max DOD error though the better because that translates into SOC error.

    I would recommend going with the bq27426 because that is the most recent IT ROM gauge with the most up to date IT features.

    thanks
    Onyx
  • 0 in reply to Onyx Ahiakwo
    Expert 1310 points
    I don't see a quick-start guide for the bq27426. Does the development process for that gauge differ significantly from that of the bq27621, bq27421, bq27441? Is there any kind of selection guide for gas gauges once I know the acceptable Chem IDs?

    Thank you,
    Adam J.
  • 0 in reply to Adam Johnson
    TI__Guru* 76230 points
    pls reference the quick start guide for the bq27421.. the devices are similar. The development process for the bq27421 or bq27441 doesn't differ significantly from the bq27426. They are all ROM based gauges.
    parametric search below but it wouldn't help you much. You are doing the right thing by reaching out to us for guidance on choosing the best IT gauge.

    www.ti.com/.../battery-fuel-gauge-products.page Management Unit;Integrated Protector

    thanks
    Onyx