What about a solder less battery build, that could be assembled by ordering parts and assembly, without spot welding and potting?
I worked in the past on solder less batteries, (2016) but did not have issues of waterproofing then…
I will work on such concept to make my 12S1P setup airplane safe (up to 20 cells per person is easy in most airplane companies) See last link, same idea.
Cells holder has holes for springs, springs push on nickel, nickel carries the load. This 10S6P was used without issue for a while.
Thermally, there was no visible hot spots on the strips :
Had a design file back in the days :
Other things I have seen done :
Also discussed here :