RobertB, as it turned out, there is a vape shop just a few blocks from my work… who knew… strange culture, vaping… Anyway, I picked up two Samsung INR18650-30Q cells, and tried them on my Convoy. Nope! Same issue. So, it’s fair to say at this point that it’s not the cell.
I found it slightly interesting that the cells came pretty much fully charged at 4.10V and 4.11V.
Maybe they were returns? I once bought some Panny 18650B’s from a highly recommended Ebay vendor and when I got them they were at 4.2v. I asked them why that was the case and he said they were returns and he also decided to test a charger on them :rage: