I have a small collection of 18650 cells from old laptop batteries that I'm now testing & "refreshing" with my bt-c3100 charger. I will use them to build 2 10s4p e-bike batteries. When the "refresh" cycles are done, the batteries are fully charged. Is it perfectly fine, or rather a bad idea to start spot welding on fully charged cells? Should I discharge each one first or doesn't this matter?
(If it does: can the bt-c3100 charger discharge to a specific voltage? I know you can change the max charge voltage, but discharge, I don't have a clue...)
I built my previous battery with new cells which had a factory charge of 3,6V, which worked great.
The old batteries have little "spikes" on the ends where I pulled off the old nickel strips, so I think I'll just sand these away and start spot welding. I am now charging all the old laptop cells in small groups. I'm not sure if I'm going to be just fine or if the thing is more likely to explode in my face if start the welding process now
Does anyone have any info on this? Thanks!