I solder after I weld because can’t easily get to the welds under the braid easily after the pack starts coming together…
What i do is, first I solder at the nickel between 2 cells, never over the top of one.
- Apply flux, scratch up the nickel and smear a coat of flux over.
- Hit it hot with the iron, large chisel tip, then right after with solder to make a little rectangle of solder across the nickel, not too much, just a coating almost
- Prep the braid by making a similar patch of solder in the braid. I use untinned copper because it doesn’t wick as much, I hold the copper braid with needle nose and that blocks any wicking past that point.
- Let the end of the braid get fully saturated with solder, while the solder is still hot, I push the braid onto the rectangle of solder on the nickel, the moment it fuses, I hit the pool of solder with a vaccum desolder gun, remove the iron while holding the braid down with the plastic vaccum puller. Let it cool, bingo.