I am wondering if anyone else has had a similar issue in that the surface finish of these Samsung cells doesn’t suit the tiny pressure contacts of the cell cage. I had problems with arcing despite the cage being fully tightened down, so did some serious looking at the surface. Under a microscope the surface is a series of peaks and troughs which seems to interfere with making a good contact. Once I had rubbed them down flat the issue disappeared. Of course the contacts in this application, by necessity, are tiny to create the high pressure it needs to simulate a spot weld but in the odd case it seems to actually prevent a satisfactory connection. I rubbed EVERY battery contact flat with fine wet/dry ..dry of course…as I don’t really want to be going through this after every ride. I then cleaned every contact with IPA. The result was an immediate improvement in the charging process. Previously the charge was VERY SLOW and peaked at 95%. Now charging is far quicker and charges fully to 100%. It’s just something to bear in mind as it wouldn’t occur if welded. It’s just a minor issue caused by a particular set of circumstances.