SUNKKO 709AD+ Battery Spot Welder for Welding Lithium-ion Battery Pack, Equipped with Cooling System and Intelligent Welding Function,110V

I'm happy with this product because it works perfectly

I bought this machine to weld 18650 battery packs. The machine mounted electrodes work decent, but the pen electrodes are marginal. This is the 110V machine, many say that the 220v model works much better. I had a lot of problems getting the pen to produce adequate welds on larger battery packs. After a many trials and errors I worked out a solution. I removed the .058 electrodes from the Pen and drilled out the the retaining holes with a .058 drill. I made new electrodes out of solid copper 14ga wire and sharpened them to a point. I would let the pen cool after every 6 cells and clean the electrodes with a fine file. This technique provided acceptable results. Good luck!

I've had the unit for over a week and haven't been able to get a decent spot weld. I repaired a couple fuse wires on a Tesla battery, but the sensitivity was very inconsistent. I'm sending the welder back to Sunkko in hopes of receiving a better 709AD+, or going with the 788A

Por el precio que tiene este equipo debería trabajar sin problemas, el soldador de estaño trabaja bastante bien , pero la de puntos no sirve para nada, mejor compren uno portable de los que usan baterías, esto no vale la pena

Same as the other guy said, this thing is junk! I can have it at 90% power, make 10 welds and still hardly have one good enough to even hold the tab on the battery. Meanwhile completely at random, 1 in 10 will arc and shoot sparks, blasting a hole right through the nickel strip and even into the battery! Last week at 30% power it blew a hole in an 18650 and sent me running through my house with a flaming battery that looked like road flare!! Oh ya, and the weld still didn't hold. lol. I hate this machine so much!