I have a Sunkko 709AD. The welder does do a half decent job for most thing, thickness of the welding matetial will be the limitation "?.2mm". As a manufacturing tool, I think you need to look at something else or have multiple units. Since building my home battery bank with 0.18mm matrerial on the GND side an welding 3 spots per cell on 4+6 pulses the handle heats up to a temperature too hot to hold in your hand after 40 battery connection " 120 weld points". Welding fuses to positive side works ok and heat on the handle bearable. I've purchased a second handle to swap over when it gets too hot.
I do like the functionality of the unit to control the pulses and current and parts are available online from multiple suppliers.
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