Hey guys,
I am currently in the process of building my first LIION battery. It is a 10s3p My 18650s just arrived today! As I went through them with my voltmeter, each cell was reading 3.5 volts. Yet, unfortunately my voltmeter doesnt read any more specific than that. How close should my LIION cells be when first building my pack? Theoretically, is it ok if one cell in my 3p is 3.5 volts and the other is 3.57 volts?
Yep within .1v is fine, you probably even have more leeway than that.
When I was building my first pack of 18650s I was scared of 0.05V difference 
Now that I think aout it I was crazy probably Anyway… what I did is i put a little magnet on both ends of the cells and set them on a metal surface with say negative terminal down and then placed another metal sheet on them connecting all of them in parallel and leaving it like thet for like a day or so… It worked beautifully but generally with new cells you have pretty much nothing to be afraid of if you have genuine cells from the same batch there should be almost no difference in their capacity and internal resistance so very little drift
Best thing to do is weld your parallel cells together and leave them for half a day-ish, then they’ll balance themselves out…
I glued all my 4p cells together, then welded them and left them to balance themselves out…
Ok great, thanks! Building as I type 
Thanks everyone!
