Hi guys,
I have a pack of 22 batteries with the black enclosures (v1 I think), I got them hooked to the Valence BMS on 20th of January and took status right before doing so. Then I took another one on 24th and then on 6th of Feb.
The pack is rewired into 5 48V groups and 2 batteries not wired, just as part of the comms network (as the BMS expects 22).
I have also changed the mode of work to "Backup" i.e. the batteries are not supposed to be discharged all the time and then charged as they were before for a while (stupid I know).
What can be seen is that the cell spread has improved a lot, but the SoC of the batteries and the battery modules voltage varies significantly (with SoC drifting further apart).
The charge voltage (the hybrid inverter is charging the pack) is 55.2V per group i.e. 13.8 per module at present.
What would you recommend that I do to get them to balance, obviously the BMS itself won't suffice. Should I charge them to a particular voltage battery by battery? What charger should I use for this, any recommendations ?
Should I be worried by these numbers, maybe is the 1st and most important question
Thanks all !
20.1.2021 | | | | | | 24.1.2021 | | | | | | 6.2.2021 | | | | |
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Batt. N | Group | U, mV | Cell Spread, mV | SoC, % | | Batt. N | Group | U, mV | Cell Spread, mV | SoC, % | | Batt. N | Group | U, mV | Cell Spread, mV | SoC, % |
1 | 1 | 13935 | 144 | 97.25 | | 1 | 1 | 13863 | 36 | 100 | | 1 | 1 | 13845 | 30 | 100 |
2 | 2 | 13692 | 62 | 81.96 | | 2 | 2 | 13702 | 32 | 100 | | 2 | 2 | 13731 | 32 | 100 |
3 | 3 | 13769 | 112 | 80.78 | | 3 | 3 | 13720 | 31 | 100 | | 3 | 3 | 13693 | 24 | 100 |
4 | 4 | 13545 | 49 | 76.86 | | 4 | 4 | 13544 | 37 | 75.29 | | 4 | 4 | 13563 | 39 | 57.25 |
5 | 4 | 13692 | 41 | 99.61 | | 5 | 4 | 13691 | 28 | 100 | | 5 | 4 | 13740 | 36 | 100 |
6 | 3 | 13423 | 10 | 80.39 | | 6 | 3 | 13491 | 31 | 80.78 | | 6 | 3 | 13539 | 46 | 79.22 |
7 | 3 | 13613 | 27 | 80.39 | | 7 | 3 | 13586 | 21 | 78.82 | | 7 | 3 | 13582 | 21 | 54.9 |
8 | 1 | 13396 | 3 | 81.18 | | 8 | 1 | 13415 | 4 | 82.35 | | 8 | 1 | 13415 | 4 | 87.84 |
9 | 3 | 13409 | 5 | 81.57 | | 9 | 3 | 13427 | 4 | 79.22 | | 9 | 3 | 13443 | 4 | 50.2 |
10 | 4 | 13457 | 18 | 76.86 | | 10 | 4 | 13462 | 21 | 73.73 | | 10 | 4 | 13461 | 21 | 45.88 |
11 | 5 | 13415 | 8 | 76.47 | | 11 | 5 | 13417 | 10 | 72.94 | | 11 | 5 | 13416 | 9 | 23.53 |
12 | 5 | 13559 | 47 | 77.25 | | 12 | 5 | 13565 | 26 | 76.86 | | 12 | 5 | 13594 | 2 | 61.57 |
13 | 5 | 13599 | 68 | 77.25 | | 13 | 5 | 13570 | 33 | 76.86 | | 13 | 5 | 13582 | 17 | 64.71 |
14 | 2 | 13397 | 3 | 75.69 | | 14 | 2 | 13404 | 4 | 76.08 | | 14 | 2 | 13443 | 14 | 72.55 |
15 | - | 13343 | 6 | 75.69 | | 15 | - | 13341 | 7 | 72.94 | | 15 | - | 13336 | 7 | 45.88 |
16 | 1 | 13432 | 7 | 77.65 | | 16 | 1 | 13452 | 18 | 78.82 | | 16 | 1 | 13466 | 35 | 80.78 |
17 | 2 | 13631 | 71 | 79.61 | | 17 | 2 | 13588 | 16 | 78.82 | | 17 | 2 | 13568 | 15 | 62.35 |
18 | 5 | 13581 | 88 | 78.04 | | 18 | 5 | 13571 | 32 | 81.18 | | 18 | 5 | 13584 | 12 | 99.61 |
19 | - | 13349 | 5 | 79.61 | | 19 | - | 13346 | 4 | 78.43 | | 19 | - | 13335 | 5 | 75.69 |
20 | 2 | 13403 | 4 | 76.47 | | 20 | 2 | 13409 | 3 | 73.73 | | 20 | 2 | 13405 | 2 | 44.71 |
21 | 4 | 13426 | 3 | 77.25 | | 21 | 4 | 13431 | 5 | 75.29 | | 21 | 4 | 13441 | 9 | 49.41 |
22 | 1 | 13398 | 3 | 77.25 | | 22 | 1 | 13410 | 6 | 77.25 | | 22 | 1 | 13438 | 22 | 67.06 |