January 16, 20251 yr 42 minutes ago, Mauritius B said: Yes, it is clear. I am not talking about "almost full" batteries, I am talking about "100%SOC" batteries that went into idle state at 52,6v, so the BMS never requested further charging up to 53,5v from the inverter and I will never be able to measure 53.5v on the terminals. You stated on post "Problem with Pylontech is that even when the data communication from BMS to the inverter is working, the BMS tells the inverter to charge till 53,5V. (=3,57V per cell)" Maybe it is something related to certain firmwares like the ones that you tested from US. Let's agree on the point that BMS in not perfect but, when batteries produced on the same batch (even with consecutive serial numbers) and connected to the same inverter are failing randomly, in my opinion, there is something else than a bad BMS design otherwise, all of them would be failing sooner or later. It is just an opinion. Download the logs from your batteries and post on here then we can have a proper look. Edited January 16, 20251 yr by Tinbum
January 16, 20251 yr There you go. Same period as shown on the picture. 1min scan intervals. 53v only hit during battery discharge and not during charge. That's curious. I am curious about how the battery can raise voltage if nothing is charging it. Grid is disconnected and PV is just barely unable to supply the loads so, some energy is taken from the battery and blended. Device mode Time AC voltage AC frequency PV input voltage PV input power Output apparent power Output active power Battery voltage Battery capacity Charging current Battery discharge current Output voltage Output frequency Battery Mode 2025-01-14 13:00:44 0.0 0.0 79.1 1517 574.0 330.0 50.8 89 23.0 0.0 229.9 50.0 Battery Mode 2025-01-14 13:01:45 0.0 0.0 74.9 1517 575.0 326.0 50.8 89 22.0 0.0 229.9 50.0 Battery Mode 2025-01-14 13:02:45 0.0 0.0 78.9 1537 575.0 333.0 50.8 89 23.0 0.0 230.1 49.9 Battery Mode 2025-01-14 13:03:44 0.0 0.0 74.7 1544 575.0 326.0 50.8 89 23.0 0.0 230.1 50.0 Battery Mode 2025-01-14 13:04:44 0.0 0.0 78.1 1575 575.0 320.0 50.9 89 24.0 0.0 230.1 50.0 Battery Mode 2025-01-14 13:05:44 0.0 0.0 77.1 1595 574.0 325.0 50.9 89 25.0 0.0 229.9 49.9 Battery Mode 2025-01-14 13:06:43 0.0 0.0 75.1 1565 575.0 324.0 50.9 89 24.0 0.0 230.1 49.9 Battery Mode 2025-01-14 13:07:45 0.0 0.0 77.2 1566 575.0 323.0 50.9 89 24.0 0.0 230.1 50.0 Battery Mode 2025-01-14 13:08:44 0.0 0.0 76.1 1551 552.0 310.0 50.9 89 24.0 0.0 230.0 50.0 Battery Mode 2025-01-14 13:09:44 0.0 0.0 79.2 1546 575.0 319.0 50.9 89 24.0 0.0 230.1 50.0 Battery Mode 2025-01-14 13:10:44 0.0 0.0 74.9 1520 575.0 319.0 50.9 89 23.0 0.0 230.2 50.0 Battery Mode 2025-01-14 13:11:44 0.0 0.0 81.2 1520 575.0 322.0 51.0 89 23.0 0.0 230.1 50.0 Battery Mode 2025-01-14 13:12:44 0.0 0.0 79.1 1523 575.0 316.0 51.0 89 23.0 0.0 230.0 49.9 Battery Mode 2025-01-14 13:13:44 0.0 0.0 77.1 1517 575.0 315.0 51.0 89 22.0 0.0 230.0 49.9 Battery Mode 2025-01-14 13:14:45 0.0 0.0 77.9 1512 575.0 324.0 51.0 89 23.0 0.0 230.1 50.0 Battery Mode 2025-01-14 13:15:44 0.0 0.0 76.6 1512 575.0 323.0 51.1 89 23.0 0.0 229.9 50.0 Battery Mode 2025-01-14 13:16:44 0.0 0.0 78.7 1514 574.0 328.0 51.1 89 22.0 0.0 229.8 50.0 Battery Mode 2025-01-14 13:17:43 0.0 0.0 75.4 1514 644.0 378.0 51.1 89 22.0 0.0 230.0 50.0 Battery Mode 2025-01-14 13:18:45 0.0 0.0 79.4 1524 621.0 364.0 51.1 89 22.0 0.0 230.0 50.0 Battery Mode 2025-01-14 13:19:44 0.0 0.0 78.7 1536 620.0 368.0 51.2 89 23.0 0.0 230.0 50.0 Battery Mode 2025-01-14 13:20:44 0.0 0.0 77.7 1544 620.0 362.0 51.2 89 23.0 0.0 229.8 50.0 Battery Mode 2025-01-14 13:21:45 0.0 0.0 77.6 1561 620.0 372.0 51.2 90 23.0 0.0 229.9 50.0 Battery Mode 2025-01-14 13:22:45 0.0 0.0 74.2 1553 575.0 314.0 51.4 92 24.0 0.0 230.1 50.0 Battery Mode 2025-01-14 13:23:45 0.0 0.0 76.2 1585 620.0 372.0 51.4 93 23.0 0.0 229.9 50.0 Battery Mode 2025-01-14 13:24:45 0.0 0.0 76.6 1598 598.0 354.0 51.5 94 24.0 0.0 230.0 50.0 Battery Mode 2025-01-14 13:25:44 0.0 0.0 74.7 1581 597.0 344.0 51.5 94 23.0 0.0 229.9 50.0 Battery Mode 2025-01-14 13:26:46 0.0 0.0 76.9 1578 621.0 369.0 51.7 95 23.0 0.0 230.0 50.0 Battery Mode 2025-01-14 13:27:46 0.0 0.0 74.9 1545 598.0 358.0 51.8 95 22.0 0.0 230.1 50.0 Battery Mode 2025-01-14 13:28:46 0.0 0.0 79.2 1551 597.0 350.0 51.9 96 22.0 0.0 229.9 50.0 Battery Mode 2025-01-14 13:29:46 0.0 0.0 78.1 1546 598.0 347.0 52.2 97 22.0 0.0 230.0 50.0 Battery Mode 2025-01-14 13:30:47 0.0 0.0 77.9 1542 575.0 360.0 52.5 97 22.0 0.0 229.9 50.0 Battery Mode 2025-01-14 13:31:47 0.0 0.0 91.7 625 598.0 345.0 52.5 99 4.0 0.0 230.1 50.0 Battery Mode 2025-01-14 13:32:46 0.0 0.0 91.4 622 598.0 355.0 52.3 100 4.0 0.0 230.0 49.9 Battery Mode 2025-01-14 13:33:47 0.0 0.0 91.4 600 598.0 351.0 52.3 100 4.0 0.0 230.1 50.0 Battery Mode 2025-01-14 13:34:48 0.0 0.0 91.2 579 598.0 352.0 52.3 100 4.0 0.0 230.1 50.0 Battery Mode 2025-01-14 13:35:47 0.0 0.0 91.1 591 598.0 350.0 52.3 100 4.0 0.0 230.0 50.0 Battery Mode 2025-01-14 13:36:48 0.0 0.0 91.1 582 598.0 360.0 52.4 100 4.0 0.0 229.8 50.0 Battery Mode 2025-01-14 13:37:49 0.0 0.0 90.9 582 597.0 354.0 52.5 100 4.0 0.0 229.9 50.0 Battery Mode 2025-01-14 13:38:48 0.0 0.0 91.9 425 574.0 344.0 52.6 100 1.0 0.0 229.9 50.0 Battery Mode 2025-01-14 13:39:48 0.0 0.0 92.1 414 598.0 346.0 52.5 100 0.0 0.0 229.9 50.0 Battery Mode 2025-01-14 13:40:49 0.0 0.0 92.1 424 575.0 346.0 52.5 100 1.0 0.0 230.1 50.0 Battery Mode 2025-01-14 13:41:49 0.0 0.0 92.2 413 574.0 343.0 52.4 100 0.0 0.0 229.9 50.0 Battery Mode 2025-01-14 13:42:48 0.0 0.0 92.2 418 597.0 358.0 52.4 100 1.0 0.0 229.9 50.0 Battery Mode 2025-01-14 13:43:48 0.0 0.0 91.7 476 667.0 415.0 52.3 100 1.0 0.0 230.0 50.0 Battery Mode 2025-01-14 13:44:49 0.0 0.0 91.7 486 666.0 404.0 52.4 100 1.0 0.0 229.9 49.9 Battery Mode 2025-01-14 13:45:49 0.0 0.0 91.7 486 667.0 418.0 52.4 100 1.0 0.0 230.0 50.0 Battery Mode 2025-01-14 13:46:48 0.0 0.0 91.7 496 667.0 422.0 52.4 100 1.0 0.0 230.0 50.0 Battery Mode 2025-01-14 13:47:47 0.0 0.0 92.4 413 621.0 359.0 52.3 100 0.0 0.0 230.0 50.0 Battery Mode 2025-01-14 13:48:48 0.0 0.0 92.2 418 598.0 353.0 52.3 100 1.0 0.0 229.9 50.0 Battery Mode 2025-01-14 13:49:47 0.0 0.0 92.2 418 621.0 369.0 52.3 100 1.0 0.0 229.8 50.0 Battery Mode 2025-01-14 13:50:49 0.0 0.0 92.2 412 621.0 359.0 52.3 100 0.0 0.0 229.9 50.0 Battery Mode 2025-01-14 13:51:47 0.0 0.0 79.1 1522 1564.0 1470.0 52.3 100 0.0 1.0 230.0 50.0 Battery Mode 2025-01-14 13:52:49 0.0 0.0 74.5 1508 1563.0 1472.0 52.3 100 0.0 2.0 230.0 50.0 Battery Mode 2025-01-14 13:53:48 0.0 0.0 78.7 1517 1561.0 1467.0 52.4 100 0.0 2.0 229.9 50.0 Battery Mode 2025-01-14 13:54:48 0.0 0.0 77.6 1524 1563.0 1460.0 52.5 100 0.0 1.0 229.9 50.0 Battery Mode 2025-01-14 13:55:49 0.0 0.0 72.9 1499 1517.0 1421.0 52.6 100 0.0 1.0 229.9 50.0 Battery Mode 2025-01-14 13:56:48 0.0 0.0 78.9 1519 1519.0 1433.0 52.7 100 0.0 1.0 230.1 50.0 Battery Mode 2025-01-14 13:57:48 0.0 0.0 76.7 1535 1518.0 1435.0 52.9 100 0.0 0.0 230.1 50.0 Battery Mode 2025-01-14 13:58:50 0.0 0.0 78.4 1544 1518.0 1425.0 53.1 100 0.0 0.0 230.0 50.0 Battery Mode 2025-01-14 13:59:49 0.0 0.0 82.4 1466 1541.0 1441.0 53.1 100 0.0 2.0 230.1 50.0 Battery Mode 2025-01-14 14:00:48 0.0 0.0 82.7 1456 1518.0 1442.0 53.1 100 0.0 2.0 229.8 50.0 Battery Mode 2025-01-14 14:01:49 0.0 0.0 82.9 1456 1518.0 1428.0 53.1 100 0.0 2.0 230.0 50.0 Battery Mode 2025-01-14 14:02:49 0.0 0.0 83.1 1445 1517.0 1425.0 53.1 100 0.0 2.0 229.9 50.0 Battery Mode 2025-01-14 14:03:49 0.0 0.0 83.4 1429 1516.0 1422.0 53.1 100 0.0 3.0 229.8 50.0 Battery Mode 2025-01-14 14:04:48 0.0 0.0 83.6 1429 1517.0 1435.0 53.1 100 0.0 3.0 229.9 50.0 Battery Mode 2025-01-14 14:05:48 0.0 0.0 83.6 1418 1518.0 1436.0 53.1 100 0.0 3.0 230.0 50.0 Battery Mode 2025-01-14 14:06:49 0.0 0.0 83.6 1413 1516.0 1434.0 53.1 100 0.0 3.0 229.9 50.0 Battery Mode 2025-01-14 14:07:49 0.0 0.0 83.6 1413 1518.0 1428.0 53.1 100 0.0 3.0 230.0 50.0 Battery Mode 2025-01-14 14:08:50 0.0 0.0 82.1 1482 1587.0 1479.0 53.1 100 0.0 3.0 230.0 50.0 Battery Mode 2025-01-14 14:09:50 0.0 0.0 81.9 1471 1587.0 1481.0 53.1 100 0.0 3.0 230.0 49.9 Battery Mode 2025-01-14 14:10:49 0.0 0.0 81.6 1466 1587.0 1493.0 53.0 100 0.0 3.0 230.0 50.0 Battery Mode 2025-01-14 14:11:49 0.0 0.0 81.1 1466 1586.0 1494.0 53.1 100 0.0 3.0 230.1 50.0 Battery Mode 2025-01-14 14:12:49 0.0 0.0 81.9 1413 1519.0 1440.0 53.1 100 0.0 3.0 230.0 50.0 Battery Mode 2025-01-14 14:13:49 0.0 0.0 82.1 1413 1518.0 1444.0 53.1 100 0.0 3.0 230.0 50.0 Battery Mode 2025-01-14 14:14:50 0.0 0.0 82.1 1402 1542.0 1444.0 53.1 100 0.0 3.0 230.0 50.0 Battery Mode 2025-01-14 14:15:49 0.0 0.0 81.2 1418 1518.0 1432.0 53.1 100 0.0 3.0 229.8 50.0 Battery Mode 2025-01-14 14:16:48 0.0 0.0 81.2 1418 1541.0 1433.0 53.1 100 0.0 3.0 230.2 50.0 Battery Mode 2025-01-14 14:17:50 0.0 0.0 81.2 1418 1518.0 1432.0 53.1 100 0.0 3.0 230.0 50.0 Battery Mode 2025-01-14 14:18:50 0.0 0.0 77.1 1443 1564.0 1467.0 53.1 100 0.0 3.0 230.0 49.9 Battery Mode 2025-01-14 14:19:49 0.0 0.0 72.5 1422 1564.0 1466.0 53.0 100 0.0 4.0 229.9 50.0 Battery Mode 2025-01-14 14:20:50 0.0 0.0 72.5 1427 1563.0 1458.0 53.0 100 0.0 4.0 229.9 50.0 Battery Mode 2025-01-14 14:21:49 0.0 0.0 80.2 1443 1564.0 1471.0 53.0 100 0.0 3.0 230.1 50.0 Battery Mode 2025-01-14 14:22:49 0.0 0.0 76.4 1465 1564.0 1466.0 53.0 100 0.0 3.0 230.1 50.0 Battery Mode 2025-01-14 14:23:49 0.0 0.0 76.4 1471 1565.0 1472.0 53.1 100 0.0 3.0 229.9 50.0 Battery Mode 2025-01-14 14:24:50 0.0 0.0 77.6 1496 1587.0 1514.0 53.0 100 0.0 3.0 229.8 50.0 Battery Mode 2025-01-14 14:25:48 0.0 0.0 75.1 1475 1587.0 1523.0 53.0 100 0.0 4.0 230.1 50.0 Battery Mode 2025-01-14 14:26:48 0.0 0.0 77.6 1468 1587.0 1522.0 52.9 100 0.0 4.0 230.0 50.0 Battery Mode 2025-01-14 14:27:49 0.0 0.0 76.4 1443 1587.0 1514.0 52.9 100 0.0 4.0 230.0 50.0 Battery Mode 2025-01-14 14:28:49 0.0 0.0 72.9 1408 1586.0 1509.0 52.7 100 0.0 5.0 229.9 50.0 Battery Mode 2025-01-14 14:29:48 0.0 0.0 78.9 1399 1587.0 1512.0 52.6 100 0.0 5.0 230.0 50.0 Battery Mode 2025-01-14 14:30:50 0.0 0.0 77.6 1391 1585.0 1509.0 52.5 100 0.0 5.0 230.0 50.0 Battery Mode 2025-01-14 14:31:49 0.0 0.0 78.6 1375 1656.0 1576.0 52.3 100 0.0 7.0 230.0 50.0 Battery Mode 2025-01-14 14:32:49 0.0 0.0 76.4 1360 1655.0 1574.0 52.1 100 0.0 7.0 229.9 50.0 Battery Mode 2025-01-14 14:33:48 0.0 0.0 77.6 1357 1633.0 1531.0 52.0 100 0.0 6.0 230.0 50.0 Battery Mode 2025-01-14 14:34:48 0.0 0.0 77.1 1350 1633.0 1534.0 51.9 100 0.0 6.0 230.1 50.0 Battery Mode 2025-01-14 14:35:50 0.0 0.0 77.2 1352 1609.0 1516.0 51.8 100 0.0 6.0 229.9 50.0 Battery Mode 2025-01-14 14:36:50 0.0 0.0 76.4 1345 1564.0 1470.0 51.7 100 0.0 5.0 230.1 50.0 Battery Mode 2025-01-14 14:37:51 0.0 0.0 76.1 1348 1564.0 1470.0 51.6 100 0.0 5.0 230.0 50.0 Battery Mode 2025-01-14 14:38:50 0.0 0.0 78.1 1369 1564.0 1467.0 51.6 100 0.0 5.0 230.0 50.0 Battery Mode 2025-01-14 14:39:50 0.0 0.0 78.1 1373 1564.0 1465.0 51.6 100 0.0 5.0 230.0 50.0 Battery Mode 2025-01-14 14:40:50 0.0 0.0 74.7 1366 1564.0 1474.0 51.5 100 0.0 5.0 230.1 50.0 Battery Mode 2025-01-14 14:41:50 0.0 0.0 77.9 1391 1563.0 1467.0 51.5 100 0.0 4.0 229.9 49.9 Battery Mode 2025-01-14 14:42:50 0.0 0.0 77.9 1369 1564.0 1465.0 51.5 100 0.0 5.0 230.1 50.0 Battery Mode 2025-01-14 14:43:49 0.0 0.0 79.6 1347 1541.0 1461.0 51.4 100 0.0 5.0 229.9 50.0 Battery Mode 2025-01-14 14:44:50 0.0 0.0 77.2 1335 1564.0 1459.0 51.3 100 0.0 5.0 230.0 50.0 Battery Mode 2025-01-14 14:45:50 0.0 0.0 77.7 1318 1563.0 1489.0 51.3 100 0.0 6.0 230.0 50.0 Battery Mode 2025-01-14 14:46:51 0.0 0.0 77.7 1306 1539.0 1454.0 51.2 100 0.0 6.0 230.0 50.0 Battery Mode 2025-01-14 14:47:50 0.0 0.0 78.4 1289 1564.0 1466.0 51.1 100 0.0 6.0 229.9 49.9 Battery Mode 2025-01-14 14:48:50 0.0 0.0 76.7 1277 1563.0 1475.0 51.0 100 0.0 6.0 229.9 50.0 Battery Mode 2025-01-14 14:49:50 0.0 0.0 77.6 1269 1563.0 1455.0 51.0 100 0.0 7.0 230.0 50.0 Battery Mode 2025-01-14 14:50:51 0.0 0.0 73.7 1242 1518.0 1415.0 50.9 100 0.0 6.0 230.1 50.0 Battery Mode 2025-01-14 14:51:50 0.0 0.0 78.6 1252 1517.0 1439.0 50.9 100 0.0 7.0 230.0 50.0 Battery Mode 2025-01-14 14:52:50 0.0 0.0 78.1 1261 1518.0 1417.0 50.8 100 0.0 6.0 229.9 50.0 Battery Mode 2025-01-14 14:53:50 0.0 0.0 78.1 1264 1518.0 1420.0 50.8 100 0.0 6.0 230.1 50.0 Battery Mode 2025-01-14 14:54:50 0.0 0.0 76.4 1262 1516.0 1409.0 50.7 100 0.0 6.0 229.9 50.0 Battery Mode 2025-01-14 14:55:51 0.0 0.0 77.4 1273 1518.0 1410.0 50.7 100 0.0 5.0 230.1 50.0 Battery Mode 2025-01-14 14:56:48 0.0 0.0 78.1 1286 1563.0 1465.0 50.6 100 0.0 6.0 230.1 50.0 Battery Mode 2025-01-14 14:57:50 0.0 0.0 78.1 1284 1562.0 1476.0 50.6 100 0.0 6.0 229.8 50.0 Battery Mode 2025-01-14 14:58:49 0.0 0.0 77.2 1273 1587.0 1480.0 50.5 100 0.0 7.0 230.0 50.0 Battery Mode 2025-01-14 14:59:50 0.0 0.0 78.1 1261 1586.0 1474.0 50.4 100 0.0 7.0 229.9 49.9 Battery Mode 2025-01-14 15:00:49 0.0 0.0 92.6 408 620.0 372.0 50.5 100 0.0 0.0 229.9 50.0 Battery Mode 2025-01-14 15:01:49 0.0 0.0 92.7 358 552.0 312.0 50.5 100 1.0 0.0 229.9 50.0 Battery Mode 2025-01-14 15:02:51 0.0 0.0 94.7 45 575.0 312.0 50.4 100 0.0 6.0 230.1 50.0 Battery Mode 2025-01-14 15:03:51 0.0 0.0 92.1 357 551.0 300.0 50.5 100 1.0 0.0 229.9 50.0 Battery Mode 2025-01-14 15:04:50 0.0 0.0 92.1 337 551.0 308.0 50.5 100 0.0 0.0 230.0 50.0 Battery Mode 2025-01-14 15:05:49 0.0 0.0 91.6 398 552.0 311.0 50.5 100 1.0 0.0 230.1 50.0 Battery Mode 2025-01-14 15:06:51 0.0 0.0 91.6 388 574.0 313.0 50.5 100 1.0 0.0 229.9 50.0 Battery Mode 2025-01-14 15:07:49 0.0 0.0 91.6 378 552.0 307.0 50.5 100 1.0 0.0 230.0 50.0 Battery Mode 2025-01-14 15:08:49 0.0 0.0 91.6 368 552.0 306.0 50.5 100 1.0 0.0 230.2 50.0 Battery Mode 2025-01-14 15:09:51 0.0 0.0 91.6 363 575.0 318.0 50.5 100 1.0 0.0 230.1 50.0 Battery Mode 2025-01-14 15:10:49 0.0 0.0 91.6 358 575.0 318.0 50.5 100 1.0 0.0 230.0 50.0 Battery Mode 2025-01-14 15:11:51 0.0 0.0 91.6 348 575.0 308.0 50.6 100 0.0 0.0 230.1 50.0 Battery Mode 2025-01-14 15:12:51 0.0 0.0 91.4 358 574.0 319.0 50.6 100 1.0 0.0 230.0 50.0 Battery Mode 2025-01-14 15:13:50 0.0 0.0 90.9 429 597.0 336.0 50.6 100 1.0 0.0 229.9 50.0 Battery Mode 2025-01-14 15:14:50 0.0 0.0 90.9 424 598.0 355.0 50.6 100 1.0 0.0 230.1 50.0 Battery Mode 2025-01-14 15:15:50 0.0 0.0 90.9 424 598.0 349.0 50.6 100 1.0 0.0 229.9 50.0 Battery Mode 2025-01-14 15:16:50 0.0 0.0 90.9 430 597.0 340.0 50.7 100 1.0 0.0 230.0 50.0 Battery Mode 2025-01-14 15:17:51 0.0 0.0 90.9 425 598.0 347.0 50.7 100 1.0 0.0 230.0 49.9 Battery Mode 2025-01-14 15:18:50 0.0 0.0 91.1 420 621.0 358.0 50.7 100 1.0 0.0 230.0 50.0 Battery Mode 2025-01-14 15:19:51 0.0 0.0 91.1 415 621.0 369.0 50.7 100 1.0 0.0 230.1 49.9 Battery Mode 2025-01-14 15:20:50 0.0 0.0 91.1 410 598.0 350.0 50.7 100 1.0 0.0 230.1 50.0 Battery Mode 2025-01-14 15:21:51 0.0 0.0 90.6 456 667.0 407.0 50.7 100 1.0 0.0 230.0 50.0 Battery Mode 2025-01-14 15:22:50 0.0 0.0 90.6 456 667.0 407.0 50.7 100 1.0 0.0 230.0 50.0 Battery Mode 2025-01-14 15:23:51 0.0 0.0 90.6 456 667.0 415.0 50.8 100 1.0 0.0 230.2 49.9 Battery Mode 2025-01-14 15:24:51 0.0 0.0 90.7 471 644.0 397.0 50.8 100 1.0 0.0 230.2 50.0 Battery Mode 2025-01-14 15:25:50 0.0 0.0 90.9 446 620.0 354.0 50.8 100 1.0 0.0 229.7 50.0 Battery Mode 2025-01-14 15:26:51 0.0 0.0 91.1 426 598.0 352.0 50.8 100 1.0 0.0 230.2 50.0 Battery Mode 2025-01-14 15:27:49 0.0 0.0 91.1 406 597.0 340.0 50.8 100 1.0 0.0 229.9 50.0 Battery Mode 2025-01-14 15:28:50 0.0 0.0 91.1 396 598.0 346.0 50.8 100 0.0 0.0 230.0 50.0 Battery Mode 2025-01-14 15:29:50 0.0 0.0 91.1 391 597.0 344.0 50.8 100 0.0 0.0 229.9 49.9 Battery Mode 2025-01-14 15:30:50 0.0 0.0 90.9 386 598.0 341.0 50.9 100 0.0 0.0 230.0 50.0 Battery Mode 2025-01-14 15:31:51 0.0 0.0 90.7 401 598.0 343.0 50.9 100 0.0 0.0 230.0 50.0 Battery Mode 2025-01-14 15:32:49 0.0 0.0 90.7 396 621.0 355.0 50.9 100 0.0 0.0 230.2 50.0 Battery Mode 2025-01-14 15:33:49 0.0 0.0 90.7 391 597.0 353.0 50.9 100 0.0 0.0 229.9 50.0 Battery Mode 2025-01-14 15:34:50 0.0 0.0 90.7 391 621.0 364.0 50.9 100 0.0 0.0 230.0 50.0 Battery Mode 2025-01-14 15:35:49 0.0 0.0 90.7 391 598.0 350.0 50.9 100 0.0 0.0 230.0 50.0 Battery Mode 2025-01-14 15:36:49 0.0 0.0 90.7 396 597.0 349.0 50.9 100 0.0 0.0 229.9 50.0 Battery Mode 2025-01-14 15:37:50 0.0 0.0 90.9 397 621.0 354.0 50.9 100 0.0 0.0 230.1 50.0 Battery Mode 2025-01-14 15:38:51 0.0 0.0 90.9 392 597.0 350.0 51.0 100 0.0 0.0 229.8 50.0 Battery Mode 2025-01-14 15:39:50 0.0 0.0 90.9 392 621.0 351.0 51.0 100 0.0 0.0 230.0 50.0 Battery Mode 2025-01-14 15:40:49 0.0 0.0 90.9 386 598.0 350.0 51.0 100 0.0 0.0 230.0 50.0 Battery Mode 2025-01-14 15:41:50 0.0 0.0 90.9 381 598.0 341.0 51.0 100 0.0 0.0 230.1 50.0 Battery Mode 2025-01-14 15:42:50 0.0 0.0 90.9 382 574.0 336.0 51.0 100 0.0 0.0 229.9 50.0 Battery Mode 2025-01-14 15:43:51 0.0 0.0 90.7 397 575.0 324.0 51.0 100 1.0 0.0 229.9 50.0 Battery Mode 2025-01-14 15:44:51 0.0 0.0 90.2 453 643.0 394.0 51.0 100 0.0 0.0 229.9 50.0 Battery Mode 2025-01-14 15:45:51 0.0 0.0 90.4 438 620.0 357.0 51.1 100 1.0 0.0 230.0 50.0 Battery Mode 2025-01-14 15:46:51 0.0 0.0 90.4 438 620.0 361.0 51.1 100 1.0 0.0 230.0 50.0 Battery Mode 2025-01-14 15:47:51 0.0 0.0 90.6 439 620.0 354.0 51.1 100 1.0 0.0 229.9 49.9 Battery Mode 2025-01-14 15:48:51 0.0 0.0 90.9 388 551.0 297.0 51.2 100 1.0 0.0 230.0 50.0 Battery Mode 2025-01-14 15:49:51 0.0 0.0 90.9 383 551.0 304.0 51.2 100 1.0 0.0 229.9 50.0 Battery Mode 2025-01-14 15:50:51 0.0 0.0 91.1 383 529.0 295.0 51.2 100 1.0 0.0 230.0 50.0 Battery Mode 2025-01-14 15:51:52 0.0 0.0 91.1 378 552.0 304.0 51.2 100 1.0 0.0 229.9 50.0 Battery Mode 2025-01-14 15:52:51 0.0 0.0 91.1 379 551.0 294.0 51.3 100 1.0 0.0 229.9 50.0 Battery Mode 2025-01-14 15:53:50 0.0 0.0 91.1 373 552.0 295.0 51.3 100 1.0 0.0 230.0 50.0 Battery Mode 2025-01-14 15:54:52 0.0 0.0 91.2 368 552.0 296.0 51.3 100 1.0 0.0 230.2 50.0 Battery Mode 2025-01-14 15:55:51 0.0 0.0 91.2 369 551.0 301.0 51.3 100 1.0 0.0 230.1 50.0 Battery Mode 2025-01-14 15:56:51 0.0 0.0 91.2 364 552.0 304.0 51.4 100 1.0 0.0 230.2 50.0 Battery Mode 2025-01-14 15:57:50 0.0 0.0 91.2 353 552.0 299.0 51.4 100 0.0 0.0 230.1 50.0 Battery Mode 2025-01-14 15:58:50 0.0 0.0 91.2 353 552.0 305.0 51.4 100 0.0 0.0 230.1 50.0 Battery Mode 2025-01-14 15:59:52 0.0 0.0 91.2 348 552.0 308.0 51.4 100 0.0 0.0 229.8 50.0 Battery Mode 2025-01-14 16:00:50 0.0 0.0 91.2 349 551.0 301.0 51.4 100 0.0 0.0 229.9 50.0 Battery Mode 2025-01-14 16:01:51 0.0 0.0 91.2 344 552.0 294.0 51.4 100 0.0 0.0 230.0 50.0 Battery Mode 2025-01-14 16:02:51 0.0 0.0 91.2 344 552.0 306.0 51.4 100 0.0 0.0 230.1 50.0 Battery Mode 2025-01-14 16:03:50 0.0 0.0 91.2 344 552.0 304.0 51.4 100 0.0 0.0 230.0 50.0 Battery Mode 2025-01-14 16:04:52 0.0 0.0 91.2 344 552.0 297.0 51.4 100 0.0 0.0 230.1 49.9 Battery Mode 2025-01-14 16:05:51 0.0 0.0 91.4 344 551.0 307.0 51.4 100 0.0 0.0 230.0 49.9 Battery Mode 2025-01-14 16:06:50 0.0 0.0 91.4 344 551.0 303.0 51.4 100 0.0 0.0 229.8 50.0 Battery Mode 2025-01-14 16:07:52 0.0 0.0 91.4 344 551.0 298.0 51.4 100 0.0 0.0 229.9 50.0 Battery Mode 2025-01-14 16:08:50 0.0 0.0 90.1 462 644.0 395.0 51.5 100 1.0 0.0 230.0 50.0 Battery Mode 2025-01-14 16:09:51 0.0 0.0 90.1 463 644.0 398.0 51.5 100 1.0 0.0 230.0 50.0 Battery Mode 2025-01-14 16:10:51 0.0 0.0 90.2 463 643.0 394.0 51.5 100 1.0 0.0 229.9 50.0 Battery Mode 2025-01-14 16:11:50 0.0 0.0 90.2 463 666.0 397.0 51.6 100 1.0 0.0 229.8 50.0 Battery Mode 2025-01-14 16:12:51 0.0 0.0 90.7 428 597.0 344.0 51.6 100 1.0 0.0 229.9 50.0 Battery Mode 2025-01-14 16:13:50 0.0 0.0 90.7 423 598.0 352.0 51.7 100 1.0 0.0 230.0 50.0 Battery Mode 2025-01-14 16:14:50 0.0 0.0 88.9 569 575.0 346.0 51.8 100 4.0 0.0 230.0 50.0 Battery Mode 2025-01-14 16:15:52 0.0 0.0 89.1 572 574.0 342.0 52.1 100 4.0 0.0 229.9 50.0 Battery Mode 2025-01-14 16:16:52 0.0 0.0 88.9 574 575.0 335.0 52.3 100 4.0 0.0 229.9 49.9 Battery Mode 2025-01-14 16:17:51 0.0 0.0 89.1 566 598.0 353.0 52.5 100 3.0 0.0 230.1 49.9 Battery Mode 2025-01-14 16:18:52 0.0 0.0 88.9 580 598.0 353.0 52.8 100 4.0 0.0 230.2 50.0 Battery Mode 2025-01-14 16:19:51 0.0 0.0 91.2 405 575.0 342.0 52.7 100 1.0 0.0 230.0 50.0 Battery Mode 2025-01-14 16:20:52 0.0 0.0 91.2 405 597.0 346.0 52.7 100 0.0 0.0 229.9 50.0 Battery Mode 2025-01-14 16:21:51 0.0 0.0 91.2 399 597.0 347.0 52.7 100 0.0 0.0 229.8 50.0 Battery Mode 2025-01-14 16:22:51 0.0 0.0 91.2 394 598.0 349.0 52.7 100 0.0 0.0 230.1 50.0 Battery Mode 2025-01-14 16:23:50 0.0 0.0 91.2 389 574.0 342.0 52.7 100 0.0 0.0 229.9 49.9 Battery Mode 2025-01-14 16:24:50 0.0 0.0 91.2 389 598.0 344.0 52.7 100 0.0 0.0 230.1 49.9 Battery Mode 2025-01-14 16:25:52 0.0 0.0 91.2 389 574.0 343.0 52.7 100 0.0 0.0 229.9 50.0 Battery Mode 2025-01-14 16:26:50 0.0 0.0 91.1 395 597.0 347.0 52.7 100 0.0 0.0 230.0 50.0 Battery Mode 2025-01-14 16:27:50 0.0 0.0 91.1 395 597.0 354.0 52.7 100 0.0 0.0 229.9 50.0 Battery Mode 2025-01-14 16:28:52 0.0 0.0 91.1 395 598.0 345.0 52.8 100 0.0 0.0 230.2 50.0 Battery Mode 2025-01-14 16:29:52 0.0 0.0 91.2 395 597.0 354.0 52.8 100 0.0 0.0 229.9 49.9 Battery Mode 2025-01-14 16:30:51 0.0 0.0 91.2 390 598.0 348.0 52.8 100 0.0 0.0 230.1 49.9 Battery Mode 2025-01-14 16:31:52 0.0 0.0 90.4 454 644.0 402.0 52.8 100 0.0 0.0 230.0 50.0 Battery Mode 2025-01-14 16:32:52 0.0 0.0 90.4 449 644.0 393.0 52.9 100 0.0 0.0 230.0 49.9
January 16, 20251 yr Thanks but, no the battery logs from BatteryView. Edited January 16, 20251 yr by Tinbum
January 16, 20251 yr 2 hours ago, Mauritius B said: 53v only hit during battery discharge and not during charge. That's curious. I am curious about how the battery can raise voltage if nothing is charging it. At a very fundamental level this is clearly impossible - the battery voltage will not go up as it is discharging. Yet, at e.g. 13:52 to 13:56, this is exactly what your data shows. Which means we need to be suspicious of the data, specifically the current measurement. If you are using Watchpower as the source of your data then that may explain it. If I remember correctly (from one of @Coulomb's many posts) the Axpert King does not actually have a current sensor and performs a fairly crude calculation to estimate it.
January 18, 20251 yr On 2025/01/17 at 4:04 AM, Calvin said: At a very fundamental level this is clearly impossible - the battery voltage will not go up as it is discharging. It could, if a cell had very high internal resistance that decreased for some reason, e.g. temperature rise. Then its sag would reduce, which increases its terminal voltage. I have not had a detailed look at the data to see if this seems to fit. It's not unusual when charging a badly discharged lead acid battery, to see the voltage initially rise, as expected, then falls for a while as its internal resistance decreases from very high to nearly normal, then rises again as the internal resistance remains low and energy accumulates in the cells. That's the same effect in reverse (charging instead of discharging).
January 18, 20251 yr @Coulomb You are right - I should have qualified my statement better. It was meant in the context of the conversation, not as a generalisation. 5 hours ago, Coulomb said: It could, if a cell had very high internal resistance that decreased for some reason, e.g. temperature rise. Then its sag would reduce, which increases its terminal voltage. I have not had a detailed look at the data to see if this seems to fit. It's not unusual when charging a badly discharged lead acid battery, to see the voltage initially rise, as expected, then falls for a while as its internal resistance decreases from very high to nearly normal, then rises again as the internal resistance remains low and energy accumulates in the cells. That's the same effect in reverse (charging instead of discharging). All true, but not pertinent: we are talking about almost fully charged LFP with negligible current. (The voltage increased by 0.8V in 5 minutes.) Edited January 18, 20251 yr by Calvin
January 18, 20251 yr Well guys, I would not blindly trust any voltage measurement that is: - measured by the inverter itself - performed while the inverter is still connected to the batteries and AC loads are ON, panels are ON. Who could be 100% sure that the voltage fluctuation is produced by the battery, not by the inverter? My 2 cents...
January 18, 20251 yr 4 minutes ago, Youda said: Well guys, I would not blindly trust any voltage measurement that is: - measured by the inverter itself - performed while the inverter is still connected to the batteries and AC loads are ON, panels are ON. Who could be 100% sure that the voltage fluctuation is produced by the battery, not by the inverter? My 2 cents... Agree, that's why I'd like to see the bms logs.
January 18, 20251 yr 15 hours ago, Calvin said: we are talking about almost fully charged LFP with negligible current. (The voltage increased by 0.8V in 5 minutes.) IMHO, this looks exactly like the inverter transitioning from CC to CV. Edited January 19, 20251 yr by Youda better wording
January 19, 20251 yr On 2024/12/27 at 11:30 AM, Youda said: Overcharge, undercharge, overheat, etc. must be a really great BMS that they are using 🙂
January 19, 20251 yr Does anyone have a technical sheet for the used Pylontech cells? I am trying to repair/replace the defective cells. Do you have an idea and possibly a procedure how to reliably test the capacity and condition of cells and identify defective ones? I have some soldered outside from the blocks and some are still in blocks of 10 cells. How much current to discharge and charge the cells during the test? I have to charge icharge x8 for the test. Edited January 19, 20251 yr by moravan30
July 29, 20251 yr On 2025/07/14 at 5:40 PM, AASda said:https://ibb.co/C3Xz9N1XokayWow 😱 Completely swollen ! Overcharging of the cells certainely. Sorry i have tried in my case to replace the cells but without success. The 20Ah Lipo4 cells are hardely soldered to the PCB 😕
February 1Feb 1 It's just the BMS that is complete garbage imho, all BMS, even cheapest one, regardless of being able to balance or not, have charge mos and discharge mos, when you reach >= 3.6 they must disable charging regardless of what inverter does...I have self made batteries with JK bms, and they disable charging as soon one cells touches 3.6 ( could be 3.65V but decided to play it safe ) , inverter keeps sending full voltage anyway
April 21Apr 21 it seems it really is a problem with Pylontech pouch cells because of overcharging. If you have a Voltronic/Axpert inverter, i would recommend to disconnect the communication cable and set inverter to USER mode, then set a lower charging current and charge voltage at 3.4V or 3.45V * cell number. (51V for 15S) That should protect from cell overcharging. Also, it seems that pylontech balancer si weak... does anybody know how many amps are used for balancing?
April 21Apr 21 1 hour ago, sethmad said:it seems it really is a problem with Pylontech pouch cells because of overcharging.If you have a Voltronic/Axpert inverter, i would recommend to disconnect the communication cable and set inverter to USER mode, then set a lower charging current and charge voltage at 3.4V or 3.45V * cell number. (51V for 15S) That should protect from cell overcharging. Also, it seems that pylontech balancer si weak... does anybody know how many amps are used for balancing?Hi @sethmad i have experienced the same problem. But in user mode, if you have not many batteries and juste 3 or 4 batteries, you will have problems like me when the batteries are low the inverter does'nt cut the batteries and the BMS will cut instead. So when the inverter have no batteries voltage it will not restart (experienced with Axpert King inverters, newer models works without but display "BP" error and does not charge the batteries). In USER mode, the inverters calculate the SoC based on batteri voltages, that doesn't represent correctly the real battery SoC.I recommend you to update to the latest Pylontech firmware (for US2000C, 3000C and newer) that modify the charging and floating voltage to 52,8V instead of 53,2V. Sadly, this update is not available for older US2000 batteries (asked pylontech staff but no answer from them) so you have to use a US2000C as master battery if you have one or keeping the USER mode.Best Regards
April 21Apr 21 On 2026/02/01 at 11:35 PM, Tiziano said:It's just the BMS that is complete garbage imho, all BMS, even cheapest one, regardless of being able to balance or not, have charge mos and discharge mos, when you reach >= 3.6 they must disable charging regardless of what inverter does...I have self made batteries with JK bms, and they disable charging as soon one cells touches 3.6 ( could be 3.65V but decided to play it safe ) , inverter keeps sending full voltage anyway@Tiziano On my pylontech batteries, when one cell is at 3,65V it disable charging (seen on US2000 and US2000C). Maybe your battery has and older firmware or faulty BMS with bad charging MOS that keep ON state (experienced on one of my Pylontech batteries). Of course, it will be more safer to lower this voltage value but it is reserved for exepert and void the pylontech warranty Best Regards
May 21May 21 I agree with Sethman. charging at 51v/51,5v you can get 95% for pylontech and Battery-View don't show HV, OV,1/ I have check that the voltronics are charging 0,7v more than the voltage configurated in the inverter.Checked whith "battery-View". You can configure 52v charge voltage, and you can see 52,7v on Battery View.And charging with a Victron mppt, if you configure 52v, Battery View realy charge at 52v.2/ The news voltronics (working with or without battery)."BP" advise, only if you start the inverter without battery. But not appear if you stop the battery while inverter is working. And if you start your voltronic without battery, if you start the battery after, your voltronic don't see the battery.
May 21May 21 On 21/04/2026 at 11:27, sethmad said:On 2026/04/21 at 11:27 AM, sethmad said: does anybody know how many amps are used for balancing?Only 50mA
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