BQ35100: BQ35100: Incorrect R and Z values

Kamlesh Bharodiya

Part Number: BQ35100
Other Parts Discussed in Thread: BQSTUDIO, EV2400

Hello Team,

I am using bqstudio with BQ35100 for guaging a LISOCL2 battery (in EOS mode -> Op config register value is set 0x02). I am getting inconsistent values of R and Z. Sometimes these are negative (as seen in the picture). Few times, it seemed correct. I went through many forum queries and followed this procedure:

1) GE high

2) Gauge Start Command (wait got [GA]=1)

3) Apply load (This step should cause at least a 100mV battery voltage drop)

4) Remove load [waited for OCV to reach upto 3.59V and After this GAUGE_STOP command initiated. Sometimes, I sent GAUGE_STOP command without waiting after load removal, however R and Z values remained negative]

5) Issue gauge stop command (Wait for GDONE, 15Sec by default)

6) Read parameters.

My setup has: discharge current: 500ma. OCV: 3.6V.

Please let me know, if I am doing anything wrong here.

Regards,

Kamlesh

over 5 years ago

0 Kamlesh Bharodiya over 5 years ago

Prodigy 140 points

This is in addition to the above query. I tested the lisocl2 battery for 2 whole days. Here are my findings:

Test Method: I follow the above steps with different load discharge duration. [for example I have discharged battery for 5, 10, 20, 30 mins duration].

In these iterations (different discharge cycles), I faced these issues:

1. Bqstudio doesn't update the SOH properly. In some iterations, it looked like, it was reduced SOH linearly (same decrease for same duration of discharge). But many times, it didn't follow the same. I was extracting same current in all these iterations.

2. Values of R and Z are very very erratic. Some values frequently seen for R: and not in the same order : 262, 36, -262, 9. 14 etc. Z is mostly at 32767 or -32767.

I am trying to integrate this fuel gauge with ESP32 microcontroller for out IOT device. Till now, I am not able to established full reliability of this IC functioning. Please help.

Regards,

Kamlesh

0 Wyatt Keller over 4 years ago in reply to Kamlesh Bharodiya

TI__Guru** 105640 points

Hello Kamlesh,

The gauge reports the EOS alert best in EOS mode, SOH is not as accurate in this mode unless you have the exact same battery as the chem ID chosen.

Were you able to program the exact chemistry ID and set the gauge ti EOS mode before the tests as well? Is this the thread you followed: e2e.ti.com/.../891336 ?

Can you log the data you are pulling with bqStudio and share it here? Also export the .gg file so we can look at the settings.

Sincerely,

Wyatt Keller

0 Kamlesh Bharodiya over 4 years ago in reply to Wyatt Keller

Prodigy 140 points

Hi Wyatt,

I have recorded the data for a new battery.

Battery: PK Cell 14000mAh 34615M LiSOCl2

Chemistry selected: 0x622

Load: 500mA [Data shows ~250mA, because I had to change the sense resistor on the EVM from 0.1 to 0.05 ohms. And I'm not able to calibrate it.]

Todays test: Started with a new battery (new battery command). The procedure was this:

1. Connected EVM through EV2400, opened BQstudio. Inserted battery. Now, I could see the registers in the BQstudio.

2. Connected load of 500mA.

3. GAUGE_START

4. Load turned on. current goes to 250mA (understandable)

5. After a minute. Load turned off. Current reduces to zero.

6. GAUGE_STOP

7. wait for GA=0 and R,Z,SOH updates.

Then again:

1. Gauge_start, load on, load off (after one minute), Gauge_stop (and see for updated values). [I dont do GE Low - as the IC is continuously turned on - hence the data is recorded continuously].

Now:

1. I understand that the chemistry is not exactly same. However, I tried to choose as close as possible (in my opinion).

2. I tried to calibrate using software and it shows this (green tick in the end. But when I refresh the register values. I dont see the changed current values.)

PFA: gg.csv file and logged data file.ic_memory_data.gg.csv

Fullscreen new_batt_EOS_mode_test1.log Download

Wed Sep 16 10:41:50 IST 2020

Device Name = bq35100
Firmware Version = 1_02


Sample,DateTime,ElapsedTime,Control,Charge Accumulation,Temperature,Voltage,Batt Stat,Batt Alert,Current,Meas_Z,ScaledR,IntTemp,SOH,Design Capacity,LogRowTime(ms),LogStatus
1,2020-09-16 10:41:55,5.001,0x40C0,0,24.2,3683,0x0005,0x0003,1,-760,-760,24.2,100,13000,191,SUCCESS
2,2020-09-16 10:42:00,10.003,0x40C0,0,24.2,3683,0x0001,0x0003,1,-760,-760,24.2,100,13000,296,SUCCESS
3,2020-09-16 10:42:05,15.002,0x40C0,0,24.2,3683,0x0001,0x0003,1,-760,-760,24.2,100,13000,214,SUCCESS
4,2020-09-16 10:42:10,20.003,0x40C0,0,24.2,3683,0x0001,0x0003,1,-760,-760,24.2,100,13000,242,SUCCESS
5,2020-09-16 10:42:15,25.003,0x40C0,0,24.2,3683,0x0001,0x0003,1,-760,-760,24.2,100,13000,330,SUCCESS
6,2020-09-16 10:42:20,30.003,0x40C1,0,24.2,3679,0x0001,0x0003,1,-760,-760,24.2,100,13000,238,SUCCESS
7,2020-09-16 10:42:25,35.004,0x40C1,0,24.2,3685,0x0001,0x0003,2,-760,-760,24.2,100,13000,289,SUCCESS
8,2020-09-16 10:42:30,40.004,0x40C1,0,24.2,3359,0x0001,0x0003,-84,-760,-760,24.2,100,13000,195,SUCCESS
9,2020-09-16 10:42:35,45.005,0x40C1,0,24.2,2906,0x0001,0x0003,-254,-760,-760,24.2,100,13000,208,SUCCESS
10,2020-09-16 10:42:40,50.005,0x40C1,0,24.2,2845,0x0001,0x0003,-253,-760,-760,24.2,100,13000,226,SUCCESS
11,2020-09-16 10:42:45,55.006,0x40C1,0,24.2,2782,0x0001,0x0003,-253,-760,-760,24.2,100,13000,242,SUCCESS
12,2020-09-16 10:42:50,60.007,0x40C1,0,24.2,2721,0x0001,0x0003,-253,-760,-760,24.2,100,13000,217,SUCCESS
13,2020-09-16 10:42:55,65.008,0x40C1,0,24.2,2677,0x0005,0x0083,-254,-760,-760,24.2,100,13000,255,SUCCESS
14,2020-09-16 10:43:00,70.008,0x40C1,0,24.2,2650,0x0001,0x0083,-254,-760,-760,24.2,100,13000,273,SUCCESS
15,2020-09-16 10:43:05,75.009,0x40C1,0,24.2,2637,0x0001,0x0083,-254,-760,-760,24.2,100,13000,189,SUCCESS
16,2020-09-16 10:43:10,80.010,0x40C1,0,24.2,2634,0x0001,0x0083,-253,-760,-760,24.2,100,13000,251,SUCCESS
17,2020-09-16 10:43:15,85.010,0x40C1,0,24.2,2637,0x0001,0x0083,-253,-760,-760,24.2,100,13000,256,SUCCESS
18,2020-09-16 10:43:20,90.010,0x40C1,0,24.2,2647,0x0001,0x0083,-253,-760,-760,24.2,100,13000,189,SUCCESS
19,2020-09-16 10:43:25,95.011,0x40C1,0,24.2,2656,0x0001,0x0083,-254,-760,-760,24.2,100,13000,201,SUCCESS
20,2020-09-16 10:43:30,100.012,0x40C1,0,24.2,2669,0x0001,0x0083,-254,-760,-760,24.2,100,13000,237,SUCCESS
21,2020-09-16 10:43:35,105.012,0x40C1,0,24.2,3511,0x0001,0x0083,0,-760,-760,24.2,100,13000,202,SUCCESS
22,2020-09-16 10:43:40,110.013,0x40C1,0,24.2,3542,0x0001,0x0083,0,-760,-760,24.2,100,13000,211,SUCCESS
23,2020-09-16 10:43:45,115.014,0x40C1,0,24.2,3562,0x0001,0x0083,0,-760,-760,24.2,100,13000,263,SUCCESS
24,2020-09-16 10:43:50,120.014,0x40C1,0,24.2,3577,0x0001,0x0083,0,-760,-760,24.2,100,13000,252,SUCCESS
25,2020-09-16 10:43:55,125.014,0x40E0,0,24.2,3579,0x0001,0x0083,0,32767,32767,24.2,90,13000,214,SUCCESS
26,2020-09-16 10:44:00,130.015,0x40E0,0,24.2,3579,0x0001,0x0083,0,32767,32767,24.2,90,13000,197,SUCCESS
27,2020-09-16 10:44:05,135.016,0x40E1,0,24.2,3600,0x0001,0x0083,0,32767,32767,24.2,90,13000,373,SUCCESS
28,2020-09-16 10:44:10,140.017,0x40E1,0,24.2,3610,0x0001,0x0083,1,32767,32767,24.2,90,13000,212,SUCCESS
29,2020-09-16 10:44:15,145.017,0x40E1,0,24.2,3404,0x0001,0x0083,-93,32767,32767,24.2,90,13000,275,SUCCESS
30,2020-09-16 10:44:20,150.018,0x40E1,0,24.2,3071,0x0001,0x0083,-253,32767,32767,24.2,90,13000,261,SUCCESS
31,2020-09-16 10:44:25,155.018,0x40E1,0,24.2,3023,0x0001,0x0083,-253,32767,32767,24.2,90,13000,239,SUCCESS
32,2020-09-16 10:44:30,160.019,0x40E1,0,24.2,2989,0x0001,0x0083,-253,32767,32767,24.2,90,13000,304,SUCCESS
33,2020-09-16 10:44:35,165.020,0x40E1,0,24.2,2948,0x0001,0x0083,-253,32767,32767,24.2,90,13000,222,SUCCESS
34,2020-09-16 10:44:40,170.020,0x40E1,0,24.2,2913,0x0001,0x0083,-253,32767,32767,24.2,90,13000,201,SUCCESS
35,2020-09-16 10:44:45,175.020,0x40E1,0,24.2,2881,0x0001,0x0083,-253,32767,32767,24.2,90,13000,993,SUCCESS
36,2020-09-16 10:44:50,180.021,0x40E1,0,24.2,2848,0x0001,0x0083,-254,32767,32767,24.2,90,13000,972,SUCCESS
37,2020-09-16 10:44:55,185.021,0x40E1,0,24.2,2816,0x0001,0x0083,-253,32767,32767,24.2,90,13000,946,SUCCESS
38,2020-09-16 10:45:00,190.022,0x40E1,0,24.2,2788,0x0001,0x0083,-253,32767,32767,24.2,90,13000,934,SUCCESS
39,2020-09-16 10:45:05,195.023,0x40E1,0,24.2,2756,0x0001,0x0083,-254,32767,32767,24.2,90,13000,942,SUCCESS
40,2020-09-16 10:45:10,200.024,0x40E1,0,24.2,2727,0x0001,0x0083,-253,32767,32767,24.2,90,13000,938,SUCCESS
41,2020-09-16 10:45:15,205.024,0x40E1,0,24.2,2701,0x0001,0x0083,-253,32767,32767,24.2,90,13000,929,SUCCESS
42,2020-09-16 10:45:20,210.024,0x40E1,0,24.2,2683,0x0001,0x0083,-253,32767,32767,24.2,90,13000,972,SUCCESS
43,2020-09-16 10:45:25,215.025,0x40E1,0,24.2,3505,0x0001,0x0083,-253,32767,32767,24.2,90,13000,931,SUCCESS
44,2020-09-16 10:45:30,220.025,0x40E1,0,24.2,3526,0x0001,0x0083,-253,32767,32767,24.2,90,13000,932,SUCCESS
45,2020-09-16 10:45:35,225.025,0x40E0,0,24.2,3533,0x0001,0x0083,-253,32767,32767,24.2,80,13000,943,SUCCESS
46,2020-09-16 10:45:40,230.026,0x40E0,0,24.2,3533,0x0001,0x0083,-253,32767,32767,24.2,80,13000,934,SUCCESS
47,2020-09-16 10:45:45,235.026,0x40E0,0,24.2,3533,0x0001,0x0083,-253,32767,32767,24.2,80,13000,928,SUCCESS
48,2020-09-16 10:45:50,240.026,0x40E0,0,24.2,3533,0x0001,0x0083,-253,32767,32767,24.2,80,13000,954,SUCCESS
49,2020-09-16 10:45:55,245.027,0x40E1,0,24.2,3587,0x0001,0x0083,0,32767,32767,24.2,80,13000,972,SUCCESS
50,2020-09-16 10:46:00,250.027,0x40E1,0,24.2,3601,0x0001,0x0083,1,32767,32767,24.2,80,13000,945,SUCCESS
51,2020-09-16 10:46:05,255.028,0x40E1,0,24.2,3386,0x0001,0x0083,-107,32767,32767,24.2,80,13000,941,SUCCESS
52,2020-09-16 10:46:10,260.028,0x40E1,0,24.2,3070,0x0001,0x0083,-252,32767,32767,24.2,80,13000,932,SUCCESS
53,2020-09-16 10:46:15,265.029,0x40E1,0,24.2,3013,0x0001,0x0083,-253,32767,32767,24.2,80,13000,942,SUCCESS
54,2020-09-16 10:46:20,270.030,0x40E1,0,24.2,2959,0x0001,0x0083,-253,32767,32767,24.2,80,13000,940,SUCCESS
55,2020-09-16 10:46:25,275.031,0x40E1,0,24.2,2915,0x0001,0x0083,-254,32767,32767,24.2,80,13000,930,SUCCESS
56,2020-09-16 10:46:30,280.031,0x40E1,0,24.2,2875,0x0001,0x0083,-254,32767,32767,24.2,80,13000,943,SUCCESS
57,2020-09-16 10:46:35,285.032,0x40E1,0,24.2,2843,0x0001,0x0083,-254,32767,32767,24.2,80,13000,940,SUCCESS
58,2020-09-16 10:46:40,290.032,0x40E1,0,24.2,2813,0x0001,0x0083,-254,32767,32767,24.2,80,13000,931,SUCCESS
59,2020-09-16 10:46:45,295.032,0x40E1,0,24.2,2786,0x0001,0x0083,-253,32767,32767,24.2,80,13000,943,SUCCESS
60,2020-09-16 10:46:50,300.032,0x40E1,0,24.2,2759,0x0001,0x0083,-253,32767,32767,24.2,80,13000,938,SUCCESS
61,2020-09-16 10:46:55,305.032,0x40E1,0,24.2,2734,0x0001,0x0083,-254,32767,32767,24.2,80,13000,930,SUCCESS
62,2020-09-16 10:47:00,310.033,0x40E1,0,24.2,2712,0x0001,0x0083,-253,32767,32767,24.2,80,13000,942,SUCCESS
63,2020-09-16 10:47:05,315.033,0x40E1,0,24.2,3482,0x0001,0x0083,1,32767,32767,24.2,80,13000,940,SUCCESS
64,2020-09-16 10:47:10,320.034,0x40E1,0,24.2,3511,0x0001,0x0083,1,32767,32767,24.2,80,13000,931,SUCCESS
65,2020-09-16 10:47:15,325.035,0x40E1,0,24.2,3527,0x0001,0x0083,1,32767,32767,24.2,80,13000,938,SUCCESS
66,2020-09-16 10:47:20,330.035,0x40E1,0,24.2,3541,0x0001,0x0083,1,32767,32767,24.2,80,13000,936,SUCCESS
67,2020-09-16 10:47:25,335.036,0x40E0,0,24.2,3544,0x0001,0x0083,1,32767,262,24.2,79,13000,931,SUCCESS
68,2020-09-16 10:47:30,340.037,0x40E0,0,24.2,3544,0x0001,0x0083,1,32767,262,24.2,79,13000,966,SUCCESS
69,2020-09-16 10:47:35,345.037,0x40E0,0,24.2,3544,0x0001,0x0083,1,32767,262,24.2,79,13000,936,SUCCESS
70,2020-09-16 10:47:40,350.037,0x40E0,0,24.2,3544,0x0001,0x0083,1,32767,262,24.2,79,13000,929,SUCCESS
71,2020-09-16 10:47:45,355.038,0x40E1,0,24.2,3586,0x0001,0x0083,0,32767,262,24.2,79,13000,938,SUCCESS
72,2020-09-16 10:47:50,360.039,0x40E1,0,24.2,3592,0x0001,0x0083,0,32767,262,24.2,79,13000,934,SUCCESS
73,2020-09-16 10:47:55,365.039,0x40E1,0,24.2,3509,0x0001,0x0083,-48,32767,262,24.2,79,13000,931,SUCCESS
74,2020-09-16 10:48:00,370.039,0x40E1,0,24.2,3067,0x0001,0x0083,-253,32767,262,24.2,79,13000,938,SUCCESS
75,2020-09-16 10:48:05,375.040,0x40E1,0,24.2,3018,0x0001,0x0083,-253,32767,262,24.2,79,13000,937,SUCCESS
76,2020-09-16 10:48:10,380.040,0x40E1,0,24.2,2966,0x0001,0x0083,-252,32767,262,24.2,79,13000,1133,SUCCESS
77,2020-09-16 10:48:15,385.041,0x40E1,0,24.2,2917,0x0001,0x0083,-253,32767,262,24.2,79,13000,1125,SUCCESS
78,2020-09-16 10:48:20,390.042,0x40E1,0,24.2,2872,0x0001,0x0083,-253,32767,262,24.2,79,13000,1120,SUCCESS
79,2020-09-16 10:48:25,395.043,0x40E1,0,24.2,2843,0x0001,0x0083,-252,32767,262,24.2,79,13000,1133,SUCCESS
80,2020-09-16 10:48:30,400.043,0x40E1,0,24.2,2812,0x0001,0x0083,-253,32767,262,24.2,79,13000,1123,SUCCESS
81,2020-09-16 10:48:35,405.044,0x40E1,0,24.2,2787,0x0001,0x0083,-254,32767,262,24.2,79,13000,1120,SUCCESS
82,2020-09-16 10:48:40,410.044,0x40E1,0,24.2,2767,0x0001,0x0083,-253,32767,262,24.2,79,13000,1130,SUCCESS
83,2020-09-16 10:48:45,415.045,0x40E1,0,24.2,2746,0x0001,0x0083,-254,32767,262,24.2,79,13000,1122,SUCCESS
84,2020-09-16 10:48:50,420.046,0x40E1,0,24.2,2728,0x0001,0x0083,-253,32767,262,24.2,79,13000,1135,SUCCESS
85,2020-09-16 10:48:55,425.046,0x40E1,0,24.2,2710,0x0001,0x0083,0,32767,262,24.2,79,13000,1128,SUCCESS
86,2020-09-16 10:49:00,430.047,0x40E1,0,24.2,3508,0x0001,0x0083,0,32767,262,24.2,79,13000,1142,SUCCESS
87,2020-09-16 10:49:05,435.047,0x40E1,0,24.2,3522,0x0001,0x0083,0,32767,262,24.2,79,13000,1133,SUCCESS
88,2020-09-16 10:49:10,440.048,0x40E1,0,24.2,3535,0x0001,0x0083,0,32767,262,24.2,79,13000,1130,SUCCESS
89,2020-09-16 10:49:15,445.048,0x40E1,0,24.2,3546,0x0001,0x0083,0,-32768,-262,24.2,79,13000,1122,SUCCESS
90,2020-09-16 10:49:20,450.049,0x40E0,0,24.2,3546,0x0001,0x0083,0,-32768,-262,24.2,79,13000,1132,SUCCESS
91,2020-09-16 10:49:25,455.049,0x40E0,0,24.2,3546,0x0001,0x0083,0,-32768,-262,24.2,79,13000,1127,SUCCESS
92,2020-09-16 10:49:30,460.050,0x40E0,0,24.2,3546,0x0001,0x0083,0,-32768,-262,24.2,79,13000,1119,SUCCESS
93,2020-09-16 10:49:35,465.051,0x40E1,0,24.2,3577,0x0001,0x0083,2,-32768,-262,24.2,79,13000,1130,SUCCESS
94,2020-09-16 10:49:40,470.052,0x40E1,0,24.2,3584,0x0001,0x0083,0,-32768,-262,24.2,79,13000,1127,SUCCESS
95,2020-09-16 10:49:45,475.052,0x40E1,0,24.2,3330,0x0001,0x0083,-125,-32768,-262,24.2,79,13000,1122,SUCCESS
96,2020-09-16 10:49:50,480.052,0x40E1,0,24.2,3023,0x0001,0x0083,-253,-32768,-262,24.2,79,13000,1130,SUCCESS
97,2020-09-16 10:49:55,485.053,0x40E1,0,24.2,2977,0x0001,0x0083,-253,-32768,-262,24.2,79,13000,1126,SUCCESS
98,2020-09-16 10:50:00,490.054,0x40E1,0,24.2,2922,0x0001,0x0083,-253,-32768,-262,24.2,79,13000,1121,SUCCESS
99,2020-09-16 10:50:05,495.055,0x40E1,0,24.2,2880,0x0001,0x0083,-253,-32768,-262,24.2,79,13000,1146,SUCCESS
100,2020-09-16 10:50:10,500.055,0x40E1,0,24.2,2846,0x0001,0x0083,-254,-32768,-262,24.2,79,13000,1154,SUCCESS
101,2020-09-16 10:50:15,505.056,0x40E1,0,24.2,2822,0x0001,0x0083,-253,-32768,-262,24.2,79,13000,1075,SUCCESS
102,2020-09-16 10:50:20,510.056,0x40E1,0,24.2,2792,0x0001,0x0083,-252,-32768,-262,24.2,79,13000,931,SUCCESS
103,2020-09-16 10:50:25,515.056,0x40E1,0,24.2,2770,0x0001,0x0083,-252,-32768,-262,24.2,79,13000,929,SUCCESS
104,2020-09-16 10:50:30,520.057,0x40E1,0,24.2,2750,0x0001,0x0083,-254,-32768,-262,24.2,79,13000,933,SUCCESS
105,2020-09-16 10:50:35,525.057,0x40E1,0,24.2,2736,0x0001,0x0083,-254,-32768,-262,24.2,79,13000,960,SUCCESS
106,2020-09-16 10:50:40,530.058,0x40E1,0,24.2,2724,0x0001,0x0083,-253,-32768,-262,24.2,79,13000,936,SUCCESS
107,2020-09-16 10:50:45,535.059,0x40E1,0,24.2,3489,0x0001,0x0083,1,-32768,-262,24.2,79,13000,927,SUCCESS
108,2020-09-16 10:50:50,540.060,0x40E1,0,24.2,3512,0x0001,0x0083,0,-32768,-262,24.2,79,13000,971,SUCCESS
109,2020-09-16 10:50:55,545.061,0x40E1,0,24.2,3525,0x0001,0x0083,0,-32768,-262,24.2,79,13000,933,SUCCESS
110,2020-09-16 10:51:00,550.061,0x40E1,0,24.2,3537,0x0001,0x0083,0,-32768,-262,24.2,79,13000,943,SUCCESS
111,2020-09-16 10:51:05,555.061,0x40E0,0,24.2,3537,0x0001,0x0083,0,-32768,-262,24.2,79,13000,943,SUCCESS
112,2020-09-16 10:51:10,560.061,0x40E0,0,24.2,3537,0x0001,0x0083,0,-32768,-262,24.2,79,13000,227,SUCCESS
113,2020-09-16 10:51:15,565.062,0x40E1,0,24.2,3560,0x0001,0x0083,1,-32768,-262,24.2,79,13000,327,SUCCESS
114,2020-09-16 10:51:20,570.062,0x40E1,0,24.2,3564,0x0001,0x0083,1,-32768,-262,24.2,79,13000,257,SUCCESS
115,2020-09-16 10:51:25,575.062,0x40E1,0,24.2,3249,0x0001,0x0083,-142,-32768,-262,24.2,79,13000,257,SUCCESS
116,2020-09-16 10:51:30,580.063,0x40E1,0,24.2,2969,0x0001,0x0083,-253,-32768,-262,24.2,79,13000,350,SUCCESS
117,2020-09-16 10:51:35,585.064,0x40E1,0,24.2,2916,0x0001,0x0083,-253,-32768,-262,24.2,79,13000,209,SUCCESS
118,2020-09-16 10:51:40,590.064,0x40E1,0,24.2,2863,0x0001,0x0083,-254,-32768,-262,24.2,79,13000,269,SUCCESS
119,2020-09-16 10:51:45,595.065,0x40E1,0,24.2,2836,0x0001,0x0083,-253,-32768,-262,24.2,79,13000,354,SUCCESS
120,2020-09-16 10:51:50,600.065,0x40E1,0,24.2,2804,0x0001,0x0083,-253,-32768,-262,24.2,79,13000,270,SUCCESS
121,2020-09-16 10:51:55,605.066,0x40E1,0,24.2,2782,0x0001,0x0083,-253,-32768,-262,24.2,79,13000,266,SUCCESS
122,2020-09-16 10:52:00,610.066,0x40E1,0,24.2,2762,0x0001,0x0083,-253,-32768,-262,24.2,79,13000,283,SUCCESS
123,2020-09-16 10:52:05,615.067,0x40E1,0,24.2,2746,0x0001,0x0083,-253,-32768,-262,24.2,79,13000,206,SUCCESS
124,2020-09-16 10:52:10,620.067,0x40E1,0,24.2,2731,0x0001,0x0083,-254,-32768,-262,24.2,79,13000,205,SUCCESS
125,2020-09-16 10:52:15,625.067,0x40E1,0,24.2,2722,0x0001,0x0083,-253,-32768,-262,24.2,79,13000,285,SUCCESS
126,2020-09-16 10:52:20,630.068,0x40E1,0,24.2,2706,0x0001,0x0083,-253,-32768,-262,24.2,79,13000,205,SUCCESS
127,2020-09-16 10:52:25,635.069,0x40E1,0,24.2,2701,0x0001,0x0083,-253,-32768,-262,24.2,79,13000,219,SUCCESS
128,2020-09-16 10:52:30,640.069,0x40E1,0,24.2,3496,0x0001,0x0083,-253,-32768,-262,24.2,79,13000,335,SUCCESS
129,2020-09-16 10:52:35,645.069,0x40E1,0,24.2,3513,0x0001,0x0083,-253,-32768,-262,24.2,79,13000,203,SUCCESS
130,2020-09-16 10:52:40,650.070,0x40E0,0,24.2,3520,0x0001,0x0083,-253,-32768,-262,24.2,79,13000,218,SUCCESS
131,2020-09-16 10:52:45,655.070,0x40E0,0,24.2,3520,0x0001,0x0083,-253,-32768,-262,24.2,79,13000,215,SUCCESS
132,2020-09-16 10:52:50,660.071,0x40E0,0,24.2,3520,0x0001,0x0083,-253,-32768,-262,24.2,79,13000,373,SUCCESS

0 Kamlesh Bharodiya over 4 years ago in reply to Kamlesh Bharodiya

Prodigy 140 points

In additions to the previous reply. This is the calibration widows snapshot.

Regards,

Kamlesh

0 Wyatt Keller over 4 years ago in reply to Kamlesh Bharodiya

TI__Guru** 105640 points

Hello Kamlesh,

The values of measured Z and scaled R is usually because the cell isn't rested when the measurements are taken. You will also need to make sure the cell is an exact match, it can't only be close for the primary cells because small changes in the voltages and resistances can cause large errors.

Sincerely,

Wyatt Keller

0 Kamlesh Bharodiya over 4 years ago in reply to Wyatt Keller

Prodigy 140 points

Hello Wyatt,

Could you please explain the meaning of 'cell to be rested'? Does it mean that the load has to be removed and when the voltage stabilises, Gauge_stop command should be sent (and parameters has to be read after GA=0).

I agree, that the cell chemistry should match. We are trying to get few batteries which has the chemistry file loaded in Bqstudio.

Regards,

Kamlesh

0 Kamlesh Bharodiya over 4 years ago in reply to Kamlesh Bharodiya

Prodigy 140 points

In addition to above, please also let me know this:

1. Is it recommended to connect load only between Gauge_start and stop commands? Can't I drain the battery (connect load and remove) and now in rested state (current = 0) follow this procedure to read SOH:

GE High -> Gauge_start -> wait for g_done =1 -> Gauge_stop -> wait for GA=0 -> read parameters

2. Does this mean that the gauge should be on as long as the load current is non-zero?

3. I see these lines in the BQ35100 TRM:

"When in this mode, a GAUGE_START() command should be issued prior to any major discharge activity.This will ensure that any major discharge pulses are used in the determination of the battery's condition. Upon completion of any major discharge, the GAUGE_STOP() command should be sent to the device."

What does "major discharge activity mean" ?

Regards,

Kamlesh

0 Wyatt Keller over 4 years ago in reply to Kamlesh Bharodiya

TI__Guru** 105640 points

Hello Kamlesh,

When you send the gauge start command the battery should be rested so the gauge can take accurate OCV readings before the load begins.

You can also perform learning pulses on the battery to get updated values for the EOS algorithm, so at predetermined times the MCU puts a load on the gauge for it to take measurements.

Major discharge activity is if you put a load on the battery cells.

Sincerely,

Wyatt Keller

0 Kamlesh Bharodiya over 4 years ago in reply to Wyatt Keller

Prodigy 140 points

Hi Wyatt,

Thanks for your response.

1. So, as far as I understand, in terms of time (for which the gauge should be on) EOS mode and ACC mode are same. Am i correct?

2. I was trying to get Lisocl2 batteries of models mentioned in the BQstudio, so that proper test can be conducted for EOS mode. My query is that if the batteries are supplied with super capacitors, (we want stable voltage), would that affect the SOH and EOS measurement of the battery (EOS mode) ?

Regards,

Kamlesh

0 Wyatt Keller over 4 years ago in reply to Kamlesh Bharodiya

TI__Guru** 105640 points

Hello Kamlesh,

For ACC mode the gauge must be on to see the current consumed. For EOS you can provide a learning pulse because it calculates the resistance of the batteries. We actually recommend using a learning pulse in set intervals if possible for EOS mode systems.

I don't believe any tests were done on this configuration so I would not be able to tell you with any certainty. But in EOS mode there is a certain time period (or number of R samples) that the gauge ignores resistance measurements to account for passivation. It may be possible to use this feature if there are any issues with gauging, but it would be more of a patched fix.

I would recommend performing your own tests on the gauge to make sure it stays accurate with large caps on the battery terminals.

Sincerely,

Wyatt Keller

0 Kamlesh Bharodiya over 4 years ago in reply to Wyatt Keller

Prodigy 140 points

Hi Wyatt,

Okay. Thanks for clarifying the doubts. Just to understand better, in one cycle - device wakes up, does some work and goes back to sleep and this happens several times in a day. Most of the time it remains on sleep. So, I think we need to start few of these cycles after turning on gauge in a day (depending on how many times in a day, we want to measure SOH). For remaining cycles, we don't need to power up the gauge (especially when we are operating in EOS mode).

Also, prior to read any meaningful SOH value, I need to discard number of SOH values depending on value of "New Batt R Scale Delay" register. Is my understanding correct?

Regards,

Kamlesh

0 Wyatt Keller over 4 years ago in reply to Kamlesh Bharodiya

TI__Guru** 105640 points

Hello Kamlesh,

Yes the gauge wakes up and does some calculations based on the data collected and goes back to sleep, how often you wake it up is dependent on your application.

Actually after looking at this further I don't believe it would help as it will only do this during the initial pulse after the NEW_BATTERY is inserted. It may be best to just test your system as if the caps are there and see if any changes need to be made.

Sincerely,

Wyatt Keller

0 Kamlesh Bharodiya over 4 years ago in reply to Wyatt Keller

Prodigy 140 points

Thanks, Wyatt. You can close this thread for now. I will test with battery with chemistry available in the Bqstudio and will get back, if any issue comes up.

Thank you again.

Regards,

Kamlesh

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BQ35100: BQ35100: Incorrect R and Z values