Ok, so i may have compromised my balancing because of the way i did it (I'll explain a little later).
I recently put into service 32x 272aH Lishen cells setup as a 2P16S configuration. The cells all arrived reading approx 3.37x volts, i parallel connected all 32 and connected my CV CC charger and set it to 3.63V. The pack took ~35amps for around 12 days.
From day 12 the current started to gradually drop, on day 14 the current dropped to ~0.5A, i raised the voltage to 3.65 and it took another 8 hours or so to come down to 0.3A which is when i disconnected. I then let the pack sit in parallel (with no charge applied) overnight. When i removed all the links in the morning every cell measured to within 0.004 volts of each other. I then started to assemble the 2P16S pack, and this is where i may have stuffed things up, i assembled the pack over two days, i got 9 pairs connected in series late on the first day then finished connecting the other 7 pairs the next day (is this is where i ruined my efforts in a good balance ??)
The pack went into service 5 days ago and is connected to a Chargery 16S BMS. When first connected the biggest V difference between cells was ~22mV, over the last five days this has gradually increased to over 130mV, I believe balancing is active as i have current in the balance leads when the yellow dashes are indicating on the display of the chargery. My MPP Solar charge settings are set to 55.4V bulk and 55.4V float. Today the diff of the two worst cells was 220mV (3.598v.......3.337v), this was while charging (<4A going into the cells), as soon as the sun went down and i was drawing from the cells the discrepancy dropped back to just under 100mV.
Do i need to perform another Top Balance and get the 2P16S connections done quicker after i remove the parallel balance links ?
The High cells are around the 11/12/13/14 cells
One other thing i must mention is my rookie error: When i first connected the Chargery BMS i connected it back to front (not in regards to polarity), what I did was connect cell monitoring wire for cell 1+ and cell 1- to cell 16 (ie I made the cell with the main positive connection as cell 1 and the cell with the main neg connection as cell 16), i had this connected and plugged into the BMS for around 10 minutes before realizing my error (note at this point the display was showing all sorts of strange voltages and the BMS case was getting, almost, too hot to touch, but not quite), Have i fried my BMS even though i'am seeing current on the leads that are indicating 'balancing in progress' ? Because it seems that no effective balancing is happening.
Any advice would be appreciated.
I recently put into service 32x 272aH Lishen cells setup as a 2P16S configuration. The cells all arrived reading approx 3.37x volts, i parallel connected all 32 and connected my CV CC charger and set it to 3.63V. The pack took ~35amps for around 12 days.
From day 12 the current started to gradually drop, on day 14 the current dropped to ~0.5A, i raised the voltage to 3.65 and it took another 8 hours or so to come down to 0.3A which is when i disconnected. I then let the pack sit in parallel (with no charge applied) overnight. When i removed all the links in the morning every cell measured to within 0.004 volts of each other. I then started to assemble the 2P16S pack, and this is where i may have stuffed things up, i assembled the pack over two days, i got 9 pairs connected in series late on the first day then finished connecting the other 7 pairs the next day (is this is where i ruined my efforts in a good balance ??)
The pack went into service 5 days ago and is connected to a Chargery 16S BMS. When first connected the biggest V difference between cells was ~22mV, over the last five days this has gradually increased to over 130mV, I believe balancing is active as i have current in the balance leads when the yellow dashes are indicating on the display of the chargery. My MPP Solar charge settings are set to 55.4V bulk and 55.4V float. Today the diff of the two worst cells was 220mV (3.598v.......3.337v), this was while charging (<4A going into the cells), as soon as the sun went down and i was drawing from the cells the discrepancy dropped back to just under 100mV.
Do i need to perform another Top Balance and get the 2P16S connections done quicker after i remove the parallel balance links ?
The High cells are around the 11/12/13/14 cells
One other thing i must mention is my rookie error: When i first connected the Chargery BMS i connected it back to front (not in regards to polarity), what I did was connect cell monitoring wire for cell 1+ and cell 1- to cell 16 (ie I made the cell with the main positive connection as cell 1 and the cell with the main neg connection as cell 16), i had this connected and plugged into the BMS for around 10 minutes before realizing my error (note at this point the display was showing all sorts of strange voltages and the BMS case was getting, almost, too hot to touch, but not quite), Have i fried my BMS even though i'am seeing current on the leads that are indicating 'balancing in progress' ? Because it seems that no effective balancing is happening.
Any advice would be appreciated.