Batteries ship at a reduced state of charge due to hazmat requirements. Legally, they can't be above 30%; however, they are often as high as 50%. At this SoC range, voltages almost always measure completely identically regardless of small variations in SoC. This is not an indication of balance at all. The only time cells are balanced is when they are at the same SoC. The only time you can say they are at the same SoC with 100% certainty is when they are completely full at 3.65V/cell or when they are completely empty at 2.50V/cell.
"grade a"
"recommended by Will"
"US Supplier"
None of the above provide confidence that a pack is top balanced. Even the smallest of SoC variations - as little as 0.1% - can create imbalance to the point the BMS cuts off charging.
You likely need to top balance your batteries.
DC clamp ammeter.
That may be the problem. Checking for current would help establish that.
I believe that is normal.
Possibly. You could manually measure your cells to check their voltage.
It doesn't work like this. The BMS is simply there as a safety system - monitoring cells and cutting out when limits are exceeded. If the battery's voltage is below the applied voltage, current flows into the battery. A 16S battery is fully charged at 56.8-58.4V.
So you have two different batteries with two different BMS with two different chargers?
Now is also a good time to triple check all cell connections and that all BMS leads are properly crimped.