The charge voltage was set to 26.8V as you suggest, during the charging it start to increase.discharge the battery again until the voltage comes down below 27.6.
Lower the charge voltage to 28volts(3.5 per) and try again.
If it fails again the same way, discharge to 27.4, lower the charge voltage to 27.6(3.45 per) and try again.
That makes no sense.The charge voltage was set to 26.8V as you suggest, during the charging it start to increase.
That makes no sense.
You can't get a battery to 28.1 volts with a charge voltage of 26.8.
You need to discharge the pack to 27.4 and then start charging at 28.4
The fact that you were charging with 26.8 volts either means you misunderstood me or I mis-typed.
I suggested that because I don't want to wait for the pack to settle.Discharging is not going to help you as all cells are dumping same current on all cells.
I was following this tutorial https://diysolarforum.com/resources...lls-using-a-low-cost-benchtop-power-supply.65
Probably better off to just stop charging and lets the balancer bleed the highest voltage cell down before starting charge again.I suggested that because I don't want to wait for the pack to settle.
I want the highest cell to not trip the bms while the psu holds the battery at a voltage in the high knee with little current flow so that the cells can balance.
Any reason you can’t unassemble the pack and do a top balance with all cells in parallel?
Then reconnect in 8s pack and then try and cycle the battery and note any anomalies?
You can do that. It is pretty safe for inexperience person to do.This may be a bit on the objectionable side- most of the stuff I do with batteries usually is haha- but I've found most balancing functions to be verryy slow and have occasionally "helped" the balancing along by hooking a 12v automotive bulb to the highest cell to drain it down some. Just something to consider...
My mistake, I looked at the 0.6 amps at top. This reverses what I said on charging current. to fill in the 21% deficient charged cell.
The doco I linked is a slightly different but related subject.I was following this tutorial https://diysolarforum.com/resources...lls-using-a-low-cost-benchtop-power-supply.65
I really don't mind the time that could take, since in the end I could get balanced cells .My mistake, I looked at the 0.6 amps at top. This reverses what I said on charging current. to fill in the 21% deficient charged cell.
So, you are converging the highest and lowest cells at about 1.6 amp rate (with balance current duty cycle dilution) plus pushing 0.6 amps charge into weakest cell. At least for current status, weakest cell which is 21% down is getting 2 amps net gain. This will drop as cells get closer to balance so you still have a long way to go.