My company has a gadget we're building in house that uses one 18650 battery each. The power leads are soldered to 0.15mm nickel contacts that are welded to the battery. We've been using one of the cheap, MOSFETs+lead acid battery type welders (the red PCB one with the modifications recommended in various places) for the early units but the results have been...variable (nickel contacts popping off the batteries during field trials, etc.)
It seems as though the market is flooded with cheap, battery-powered and slightly more expensive AC-powered spot welders from China.
My question: Is this all you can get now or is there something better?
I've searched online but I keep coming up with all the same usual suspects (Glitter, Sunkko, U.S. Solid).
Ideally, we were hoping to find something that runs off AC power (120V preferred but we could make 220V work if needed) that you can get replacement parts for when/if needed. Does something like that even exist?
Are there other brands than those mentioned above? What were people using years ago before all these China battery welders appeared?
Eventually, we'll be building 2000+ of these gadgets and I want to make sure we're not being let down by poor tools. If the answer is, "The cheap tools work perfectly. You just don't now how to use them properly", then please enlighten me
This is something that's a bit new to us and we want to get it right.