• 状态
  • 回复 6 回复
  • 订户 57 订户
  • 视图 100 视图
  • 用户 0 会员在此处
选项
选项
相关

BQ4050: Reasons for the dispersion of MaxError values in BQ4050

yanqing liu
Prodigy 60 points
Part Number: BQ4050


Hi  TI Experts

We have designed a 3S3P NMC battery power management solution using the BQ4050.  After re-reading the battery log records following a period of usage, as shown in the table below, we observed the following:
While most battery cycle counts range between 100–200 cycles, the MaxError values are highly scattered. At 200 cycles, for instance, MaxError values include 2%, 49%, and even 100%. However, the SOH and FCC of the batteries show no significant abnormalities. Could you please help clarify the following questions:

1. What is the calculation method for MaxError? There is no relevant explanation in the TRM.
2. What causes such a wide dispersion in MaxError values? Is this phenomenon normal?
3. Can such scattered MaxError values indicate a mismatch between BQ4050 parameters and the battery cells? Could it be due to issues in BQ4050 parameter design, or improper settings during battery usage?
4. Under normal circumstances, what is the approximate relationship between MaxError and cycle count? Is there a rough estimation method?
5. How reliable is MaxError? Can it be used as a criterion for determining battery degradation?
6. If the answer to question 5 is affirmative, what is the method for judging battery degradation using MaxError? If not, aside from SOH, could you provide examples of other parameters in the BQ4050 log that can be used to assess battery degradation?

BQ4050 log.xlsxThe complete gg file and log file are attached. Please review and confirm as soon as possible. Thank you!

MaxErr RSOC ASOC SOH RemCap FullChgCap ChgCurr ChgVolt BattStat CycleCnt
34 58 59 100 5297 9213 3750 12600 0x00C0 219
14 70 71 100 6344 9186 3750 12600 0x00C0 225
26 70 72 100 6433 9195 3750 12600 0x00C0 216
46 100 102 100 9142 9188 44 12600 0x00E0 214
13 94 96 100 8556 9190 3750 12600 0x00C0 200
100 52 53 100 4766 9263 3750 12600 0x00C0 210
8 86 87 100 7753 9095 3750 12600 0x00C0 226
2 67 67 99 5970 8951 3750 12600 0x00C0 224
2 77 77 100 6901 9051 3750 12600 0x00C0 167
8 96 97 100 8727 9146 44 12600 0x00E0 214
8 99 101 100 9028 9163 44 12600 0x00E0 208
4 100 99 99 8836 8870 44 12600 0x00E0 203
100 88 90 100 8063 9263 3750 12600 0x00C0 212
3 87 87 100 7757 8962 3750 12600 0x00C0 212
16 87 90 100 8077 9305 3750 12600 0x00C0 214
15 91 93 100 8293 9200 3750 12600 0x00C0 216
100 67 69 100 6136 9263 3750 12600 0x00C0 210
33 65 67 100 6019 9373 3750 12600 0x00C0 212
39 65 66 100 5871 9060 3750 12600 0x00C0 220
49 94 99 100 8844 9466 3750 12600 0x00C0 192
48 99 100 100 8976 9107 44 12600 0x00E0 199
37 78 80 100 7145 9241 3750 12600 0x00C0 218
100 87 90 100 8031 9263 3750 12600 0x00C0 159
100 100 103 100 9204 9263 44 12600 0x00E0 163
26 92 96 100 8621 9416 3750 12600 0x00C0 125
100 100 103 100 9200 9263 44 12600 0x00E0 103
100 65 67 100 5962 9263 3750 12600 0x00C0 128
27 69 71 100 6323 9269 3750 12600 0x00C0 134
5 100 100 100 8976 9040 44 12600 0x00E0 128
100 67 69 100 6125 9263 3750 12600 0x00C0 134
2 63 63 100 5621 9004 3750 12600 0x00C0 133
2 77 78 100 6970 9149 3750 12600 0x00C0 132
11 53 55 100 4948 9349 3750 12600 0x00C0 121
100 99 102 100 9170 9263 3750 12600 0x00C0 131
100 77 79 100 7068 9263 3750 12600 0x00C0 133
100 76 79 100 7032 9263 3750 12600 0x00C0 105
100 87 90 100 8042 9263 3750 12600 0x00C0 57
2 100 101 100 9052 9097 44 12600 0x00E0 128
100 65 67 100 5946 9263 3750 12600 0x00C0 135
100 65 67 100 5946 9263 3750 12600 0x00C0 135
32 86 87 100 7744 9075 3750 12600 0x00C0 132
100 86 89 100 7957 9263 3750 12600 0x00C0 130
100 100 103 100 9217 9263 44 12600 0x00E0 134
100 95 97 100 8708 9263 3750 12600 0x00C0 141
100 73 75 100 6692 9263 3750 12600 0x00C0 131
100 92 95 100 8481 9263 3750 12600 0x00C0 136
16 62 63 100 5651 9193 3750 12600 0x00C0 127
30 87 89 100 7966 9205 3750 12600 0x00C0 138
4 65 67 100 5957 9226 3750 12600 0x00C0 134
25 70 72 100 6428 9292 3750 12600 0x00C0 126
27 55 57 100 5042 9284 3750 12600 0x00C0 133
17 94 97 100 8676 9311 3750 12600 0x00C0 126
8 74 77 100 6884 9371 3750 12600 0x00C0 132
100 64 65 100 5844 9263 3750 12600 0x00C0 119
4 78 80 100 7166 9292 3750 12600 0x00C0 134
31 92 97 100 8723 9490 3750 12600 0x00C0 128
100 79 81 100 7245 9263 3750 12600 0x00C0 130
6 88 91 100 8119 9321 3750 12600 0x00C0 122
27 67 67 100 5967 9016 3750 12600 0x00C0 122
5 94 97 100 8642 9221 3750 12600 0x00C0 110
8 96 100 100 8966 9369 3750 12600 0x00C0 126
7 96 98 100 8798 9243 3750 12600 0x00C0 130
100 22 23 100 2007 9263 3750 12600 0x00C0 131
33 78 81 100 7238 9299 3750 12600 0x00C0 130
15 94 95 100 8461 9084 3750 12600 0x00C0 86
27 50 51 100 4562 9188 3750 12600 0x00C0 136
100 87 90 100 8042 9263 3750 12600 0x00C0 127
31 78 82 100 7368 9505 3750 12600 0x00C0 131
19 100 102 100 9119 9165 44 12600 0x00E0 137
100 61 63 100 5605 9263 3750 12600 0x00C0 133
6 68 69 100 6192 9184 3750 12600 0x00C0 132
5 72 75 100 6716 9432 3750 12600 0x00C0 132
17 55 57 100 5051 9214 3750 12600 0x00C0 132
34 95 97 100 8695 9158 3750 12600 0x00C0 134
14 74 76 100 6810 9299 3750 12600 0x00C0 127
100 94 96 100 8621 9263 3750 12600 0x00C0 107
100 69 71 100 6338 9263 3750 12600 0x00C0 133
100 95 98 100 8737 9263 3750 12600 0x00C0 126
5 98 99 100 8857 9058 44 12600 0x00E0 218
8 99 101 100 9012 9130 44 12600 0x00E0 215
38 100 103 100 9226 9234 44 12600 0x00E0 224
2 99 100 100 8995 9092 44 12600 0x00E0 134
2 50 50 100 4466 9033 3750 12600 0x00C0 163
2 50 51 100 4536 9244 3750 12600 0x00C0 192
4 99 102 100 9105 9205 44 12600 0x00E0 206
11 99 101 100 9053 9168 44 12600 0x00E0 208
2 51 50 99 4497 8914 3750 12600 0x00C0 210
20 11 11 100 984 9120 3750 12600 0x00C0 149
16 99 100 100 8979 9148 44 12600 0x00E0 207
2 57 59 100 5284 9315 3750 12600 0x00C0 9
4 100 100 100 8931 9016 44 12600 0x00E0 141
16 100 103 100 9205 9210 44 12600 0x00E0 133
2 31 33 100 2962 9622 3750 12600 0x00C0 2
38 98 100 100 8934 9138 44 12600 0x00E0 182
100 29 30 100 2651 9364 3750 12600 0x00C0 3
2 50 51 100 4581 9280 3750 12600 0x00C0 49
100 100 103 100 9231 9263 44 12600 0x00E0 118
2 12 12 100 1068 9699 3750 12600 0x00C0 8
100 100 103 100 9257 9263 44 12600 0x00E0 125
17 99 102 100 9153 9267 44 12600 0x00E0 133
2 99 102 100 9163 9260 44 12600 0x00E0 133
2 74 76 100 6759 9225 3750 12600 0x00C0 48
8 100 103 100 9222 9253 44 12600 0x00E0 128
14 99 104 100 9286 9404 44 12600 0x00E0 130
100 100 103 100 9258 9263 44 12600 0x00E0 129
10 100 103 100 9208 9214 44 12600 0x00E0 133
2 99 101 100 9084 9182 44 12600 0x00E0 134
2 33 33 100 2948 9177 3750 12600 0x00C0 109
100 99 102 100 9170 9263 3750 12600 0x00C0 125
8 98 101 100 9024 9235 44 12600 0x00E0 103
2 50 50 100 4488 9048 3750 12600 0x00C0 123
100 100 103 100 9257 9263 44 12600 0x00E0 132
10 31 33 100 2883 9300 3750 12600 0x00C0 79
6 100 102 100 9141 9184 44 12600 0x00E0 132
2 1 1 100 24 9203 3750 12600 0x02D0 128
25 30 33 100 2919 9775 3750 12600 0x00C0

83