I'm gonna build battery packs. I have quite a lot of experience with 18650 Li-ion cells, but there's one thing I still don't know.
I will buy CCA 100 new cells from seller (for example LGEBHE21865). There are multiple batches of cells (the number below battery model). Although the batteries are 2500 mAh nominal, actual capacity differs ±100 mAh.
My question is:
It is better to build a pack (5S2P for example) using only cells from the same batch or measure actual capacity of each cell and use cells with most similar capacity? Or is there another important aspect like internal resistance?