I am going to be building a 2S4P (8 cells total)li-ion battery pack for my old RC. I am going to attach leads, positive and negative, on each set of 4 parallel cells for charging on a lab supply. Now the negative charging leads on the first 4 cells are obviously connected to the positive pole of the second set of parallel cells. Won't there be any complications in this setup when I charge one set of parallel cells at a time?

 

It'll be OK as long as there is no series circuit - only a parallel connection of the charger to the 4 parallel cells, one set at a time as you said.

 

Ok thanks. Just wanted to make sure.