Cogging/9920 Problem

[Nick]

I have had a look and they look fine but I've redone my batteries. Put new bars on, new wires. Redone all the connections anyway, as they needed a refresh. I'm just letting the glue dry then I'll run them, I noticed on a few the shrink-wrap has worped away, leaving the cell casing in view (silver bit) I wonder if when 2 cells touch each other, it short circuits it?

Jumper is on fine.

Could it be anything else? :(