There is a way to export your settings to a PDF from your 18K,
Just to correct you on the statement. With this LiFePo4 chemistry same voltage does NOT equal same SOC% for about 1%-99% SOC.
Your batteries are fine, but likely the SOC level is giving you garbage readings. If you don't have time for the nonsense with weeks and months of back and forth with support just disregard the soc and trust in your shunt for SOC, use them in lead acid mode
It doesn't appear to be that simple with LPF batteries.
They will want to achieve equilibrium in voltage (which may or may not reflect on the BMS indicated soc).
Yes they would equalize somewhat. However due to the very flat voltage curve they may never reach equilibrium just sitting there connected. Same voltage but different level of charge. Need to cycle the batteries for them to get in sync.
Problem I am having is BMS is going into alarm and disconnecting the charging at 3.5V with other cells at 3.4V, data in previous post. I did some step charging and discharging and did get one battery to sync with the others. I have new one that is doing it now. I'll discharge it and bring it back up. Taking a lot more time and effort that I expected. I can see this being a per month maintenance issue.
Consider reducing the charging voltage to 3.400 Vpc until all is synchronized better. If planning to charge to 3.500 Vpc the alarm should be increased to 3.600 to 3.650 Vpc. Never going to be so perfectly balanced to charge at the alarm level.
Once the cells become well top balanced, they should become stable and the small balance current from the BMS should be enough to keep them in check. The main problem with the initial balance is the BMS only has about 0.1 amp of balance current. So for it to truly be able to balance, the charge current can only be that 0.1 amp as well. Then the BMS can literally stop the high cell from charging and allow the other cells to catch up. Once they achieve a good balance, the slight differences in charge rate can typically be managed with the small balance current.
I was aiming for 3.45 but the imbalance would make one cell go over 3.5 while the other was a 3.3 and change. My one success story was to run it down to 80% let it sit and then take it up to 55.2 and hold it. I'll get more creative next time around. Start work week back up.
So the problem child has ben tamed. Now having fun with the two new rack batteries. I ran them down, charged them up, and still had an imbalance. So what seems to be the fastest method is go run the battery 1/2 way down with a 1kw mini-split so I don't feel like I am wasting any energy. As they get close to each other I bring it up with 10 amps but only 1 volt at a time until the current goes to zero and they balance out. I kept walking them up until I got to 56.2 and held it there until current and differential voltage went away. On the last battery and looks good so far. Mid-Level staircase method to coin a term?
I am going though a agenizing painful process of slowly walking them up. It is my understanding that 3.45-3.5V is where the BMS active starts to balance from observation. Above 3.5 it just alarms out possibly due to cell differential. I have the ChargeVerter set for 1A (lowest) to go to 55.2V on this battery hoping they will balance out at 3.45V. Once I get them there I can walk them up to at least 56.2 and I am gold from there out. I don't want to change any factory setting in the battery/BMS. I want to find the least painful that works in my setup.
Thanks for reminding me. I am at cell OV but not shut down. That will keep the process going.
I've had similar issues with my setup. Cycling them seems to be the solution, but it's not the most convenient, especially if you're not a heavy power user.
Sorry for the late reply and thanks for your input. I don't get alerts.
This is not a big surprise with LFP cells. From 20% to 80% the voltage changes so slow that the batteries look well balanced, even if they are pretty far out. When the pack seemed to be at 50%, maybe one cell was actually 60% and the rest were at 40%. The voltages are all near identical, LFP does that. Then while charging, the one cell that was 60% is now passing 80%. It will start to run away and the voltage will climb fast. The other cells are only at 60% and their voltage still climbs very slow. So the balance looks like it goes way out. In fact, it always was out all along, but the voltage curve hides that the cells were that out of balance until you try to charge up to the top.
