BQ78PL116: Dynamic Impedance values for Gas Gauge calculations

Hi Marcus,

The Ra values are unusual.

At first blush, the values may indicate either (1) damaged cells or (2) damaged/resistive connections.

Please check the cells and connections.

Are you seeing these results across multiple packs? Is this a one-off situation?

Please test with another pack as well.

Sincerely,
Bryan Kahler

Hi Bryan,

Thanks for your help!
This issue is present on all batteries out of this series (n>100). The batteries are running well, however the SOC values are unreliable.

I am a step forward now: I've checked the auxilary file we have generated and imported: the values there seem to be the reason for those crazy Ra values (see attachment): values higher than 2 byte create an overrun: an imported value of 65535 results in "65535" in the BQ-Ra register, an imported value of 65537 results in a "1".

I did the AUX-file generation again, however with the same result: the Ra-values are still invalid.

Maybe there is something wrong with our log-file? Could you possibly check it for me? (I cannot attach it here, please advice how to provide it)

Thanks a lot,
Marcus


AUX File:
*****************************************************************************************************************
# bq78PL114 auxillary chemistry data for chemistry type 463
# aux_gui version 2.00 - Actual
# based on P:\KIS_OS_20170123.csv log file
# Generated for 8S13P pack
# Generated : 24.01.2017 08:34:39
bqWizard # Application
2.5 # minimum BqWizard version
1 # # of files
15 # File #
AuxChem # File Type
2 # ChunkSize
360 # Total bytes
##############################################
# Comments to be included in the .aux file
##############################################
1 # Aux_Chem serial
21 # Tau10
2930 # NDI_LowT
3030 # NDI_HighT
15 # NDI_SOC
0 # Spare0
32 # NDI_GAIN
0 # Spare1
0 # Spare2
0 # Spare3
0 # Spare4
0 # Spare5
########### cell 1 ##################
17 # NDI_Initial
17 # NDI
4250 # QMax
2127 # QRem
0 # Rzero
0 # Spare
1442 # Ra[ 0]
1486 # Ra[ 1]
1680 # Ra[ 2]
1540 # Ra[ 3]
1895 # Ra[ 4]
2259 # Ra[ 5]
3049 # Ra[ 6]
12584 # Ra[ 7]
20318 # Ra[ 8]
55167 # Ra[ 9]
75355 # Ra[10]
84839 # Ra[11]
104105 # Ra[12]
22128 # Ra[13]
115074 # Ra[14]
########### cell 2 ##################
16 # NDI_Initial
16 # NDI
4260 # QMax
2128 # QRem
0 # Rzero
0 # Spare
1398 # Ra[ 0]
1440 # Ra[ 1]
1654 # Ra[ 2]
1507 # Ra[ 3]
1857 # Ra[ 4]
2242 # Ra[ 5]
3067 # Ra[ 6]
12876 # Ra[ 7]
21121 # Ra[ 8]
56654 # Ra[ 9]
77924 # Ra[10]
90220 # Ra[11]
110708 # Ra[12]
23531 # Ra[13]
122373 # Ra[14]
########### cell 3 ##################
18 # NDI_Initial
18 # NDI
4260 # QMax
2128 # QRem
0 # Rzero
0 # Spare
1583 # Ra[ 0]
1631 # Ra[ 1]
1832 # Ra[ 2]
1711 # Ra[ 3]
2102 # Ra[ 4]
2516 # Ra[ 5]
3367 # Ra[ 6]
14037 # Ra[ 7]
22946 # Ra[ 8]
61951 # Ra[ 9]
84051 # Ra[10]
93679 # Ra[11]
114953 # Ra[12]
24433 # Ra[13]
127064 # Ra[14]
########### cell 4 ##################
17 # NDI_Initial
17 # NDI
4270 # QMax
2134 # QRem
0 # Rzero
0 # Spare
1429 # Ra[ 0]
1472 # Ra[ 1]
1692 # Ra[ 2]
1548 # Ra[ 3]
1924 # Ra[ 4]
2288 # Ra[ 5]
3108 # Ra[ 6]
12986 # Ra[ 7]
21168 # Ra[ 8]
57731 # Ra[ 9]
78896 # Ra[10]
88430 # Ra[11]
108512 # Ra[12]
23064 # Ra[13]
119945 # Ra[14]
########### cell 5 ##################
21 # NDI_Initial
21 # NDI
4280 # QMax
2138 # QRem
0 # Rzero
0 # Spare
1452 # Ra[ 0]
1496 # Ra[ 1]
1696 # Ra[ 2]
1569 # Ra[ 3]
1926 # Ra[ 4]
2335 # Ra[ 5]
3130 # Ra[ 6]
13189 # Ra[ 7]
21177 # Ra[ 8]
57679 # Ra[ 9]
79487 # Ra[10]
89142 # Ra[11]
109386 # Ra[12]
23250 # Ra[13]
120910 # Ra[14]
########### cell 6 ##################
19 # NDI_Initial
19 # NDI
4270 # QMax
2136 # QRem
0 # Rzero
0 # Spare
1375 # Ra[ 0]
1417 # Ra[ 1]
1634 # Ra[ 2]
1481 # Ra[ 3]
1833 # Ra[ 4]
2210 # Ra[ 5]
2974 # Ra[ 6]
12501 # Ra[ 7]
20143 # Ra[ 8]
54701 # Ra[ 9]
75401 # Ra[10]
85526 # Ra[11]
104948 # Ra[12]
22307 # Ra[13]
116006 # Ra[14]
########### cell 7 ##################
19 # NDI_Initial
19 # NDI
4270 # QMax
2136 # QRem
0 # Rzero
0 # Spare
1446 # Ra[ 0]
1490 # Ra[ 1]
1701 # Ra[ 2]
1574 # Ra[ 3]
1933 # Ra[ 4]
2343 # Ra[ 5]
3159 # Ra[ 6]
13394 # Ra[ 7]
21639 # Ra[ 8]
58745 # Ra[ 9]
80865 # Ra[10]
91961 # Ra[11]
112845 # Ra[12]
23985 # Ra[13]
124734 # Ra[14]
########### cell 8 ##################
16 # NDI_Initial
16 # NDI
4270 # QMax
2135 # QRem
0 # Rzero
0 # Spare
1387 # Ra[ 0]
1429 # Ra[ 1]
1639 # Ra[ 2]
1482 # Ra[ 3]
1846 # Ra[ 4]
2212 # Ra[ 5]
2967 # Ra[ 6]
12310 # Ra[ 7]
19997 # Ra[ 8]
54497 # Ra[ 9]
75984 # Ra[10]
85835 # Ra[11]
105328 # Ra[12]
22388 # Ra[13]
116425 # Ra[14]
********************************************************************************************************