

Or the loose connection on the other side is manifesting itself. Try fixing the stepped connections on the other side and check all connections and give the cells a couple of charge cycles to see what settles out. If they were not well parallel top balanced it might take more cycles for them to even out at the top. The charge/discharge curves are so flat in the middle voltage of 3.2 volts. Any voltage deltas there are not much value. Also try to avoid taking the cells below 3.0 volts until you know you have a good balance at the top. A good top balance will be evident at 3.45 volts or greater per cell.maybe it is just the lowest cells that get discharged firstor
Oy ve.However I've kept the steps on the other side of the pack to see if it causes a drop there now instead.
Stacking busbars is not a great idea. In my opinion, its also best to use a BMS per 16s pack instead of packing cells in parallel for ah gain. This way every cell can be monitored, and one bad cell does not affect the whole pack.Oy ve.
Just LOOK at them.
At the very bottom of the ramp is the only connection to the adjacent bus bar or the cell terminal that you have.
This is not good practice.
Do you want the battery to work correctly or do you want to continue chasing guesses?
I follow all of the above, especially the use of NoAlox or any antioxident when going from Aluminum to copper or tinned bus bars.You won’t believe how incredibly important it is............
The OP has a 2P4S pack and it would be more practical for him to finish the diagnosis before disassembling the entire pack and purchasing anotheer BMS. Unless ther is a strong need for redundancy in packs, some parallel configurations can be successful. My own pack is 3P16S and it has worked this way for two years. If a cell loses capacity it will be propped up by the parallel cells but the problem can be detected during cell charging. I do keep spares for that eventuality. I have been using similar cells for over three years and have not yet experienced rapid cell failure with these or any of the combinations of cells I have been using in the past twelve years. The exception is an over discharge of a Headway pack ten years ago before I realized the value of a BMS. I had no low voltage protection and I drove that e bike to the point that one cell reversed and eventually blew the vent.best to use a BMS per 16s pack instead of packing cells in parallel
You won’t believe how incredibly important it is to have clean flat contact contact on the terminals.
Do you mean 3M Medium Grit Emory Cloth like this: https://www.amazon.com/3M-Pro-Pak-Medium-9-Inch-11-Inch/dp/B0002YQ2YMI use medium 3M abrasive cloth and give the post contact surface a twist to get the oxides off. Then I give the contact surfaces of the busses and lugs a quick buff. Dust off or carefully blow off (away from the vent) any residue and avoid getting abrasive into the threads.
After prepping, you will want to immediately assemble because aluminum oxidation begins quickly.
This: https://www.amazon.com/NO-OX-ID-Spe...ords=no+ox+id+a+special&qid=1691283005&sr=8-1Use an anti oxidant or dielectric like No-Ox A-special, silicone GREASE or marine grease(synthetic) on the contact surface but not the threads because that can increase the tension on the threads in the terminal. Don’t worry, excess dielectric moves out of the way and you have great connections yet the air is kept out.
I cleaned with ScotchBrite, assembled quickly and torqued to 4Nm when I built my battery 3 years ago, but skipped any kind of NOALOX.Torque no more than 4Nm.