This is a very capable welder. So far I have been able to weld 0.35mm copper using about 94% of max power, and using the welding flux/ brazing paste.
I can weld 0.2mm copper under 0.1mm Stainless steel(304) Without Flux, at gear 550, single pulse, no preheating. This was to judge to another welder that claimed 10KW output. Reports from that user is that it could just barely weld it.
The instructions are not translated well. The preheating duration can almost be though of as another pulse, and the 'intermittent; is the time between the preheating pulse, and the first welding pulse. The 'intermittent' is NOT the interval between welding pulses.
That Interval has to be set in 0.1 second increments on the Main menu page.
I have not fully experimented with the preheating duration, the 'intermittent' duration between that preheating pulse, and the first welding pulse( of potentially 3), nor the interval between welding pulses.
These features should allow one to really fine tune the welds so the least amount of energy can be used to weld the chosen material and its thickness to the cell.
One can turn off the preheating and just use a single pulse and not worry about these additional features also. It has more than enough power to weld very reasonable thicknesses of copper or Nickel to a cell without the extra bells and whistles.
The welding Flux for the 'copper to copper' welding works well at welding the copper strips to the Nickel plated steel battery. It reduces the power required, and it actually tins the copper a certain distance from the weld spots. The more power used the more the copper is tinned in proximity to the welds.
This might further reduce resistance of the welded joint.
One can weld 0.2mm copper without any Nickel/nickel steel. Stainless steel sandwich or without flux, but it requires far less power if both are used, and is likely far better for the cell's ultimate longevity.
Thee welding pens are comfortable and the leads are about 4 gauge and very flexible. The spiral wrapping looks wrong in the photos but it helps dissipate heat better than Silicone jacketing would. The tips are easily replaced using only fingers on teh knurled threaded collets, but I like to give a bit more torque with some plyers as I have had the tip loosen.
The 9 volt 15 amp power supply has a little fan inside of it that runs for a short period after a weld, and runs longer the higher the gear that is used, as well as if one is using double or triple pulse..
The foot pedal has a very solid feel and plenty of cord length to route it out of the way.
The interface to change gears and other settings takes some time to get used to and I often have to rescroll through it to do what i want. The machine can be flipped 180 degrees and the screen can be flipped, but I'd like the option to put it on its side, and rotate the screen 90 degrees.
It would be nice it it came with Antislip feet.
None of my batteries past oand most likely future really require more than 0.2mm copper, but it is nice knowing I can go as thick as 0.35 under 0.1mm stainless steel, using the flux. I was able to get 0.4mm copper to stick, where I could not rip it off by hand, but using Pliers it came off too easily in my opinion.
That was gear 940 double pulse. I don't really want to use gear 999 and triple pulse just to see if it is possible, and I didn't really play with the preheating or the intermittent or the interval at that extreme power level.
When one is not using enough power, one weld will be noticeably smaller and weaker than the other.
Also note that if used to other welders, that might have been very sensitive to the amount of downward pressure used. This welder seems far less sensitive to the force used. Use enough to make sure the material is pushed flat to the battery, and lift just a little before pressing the pedal, or before it automatically fires at your chosen delay.
If you are throwing a lot of sparks on each weld make sure the tips are clean. The included file is very aggressive, and some 220 to 320 grit sandpaper might allow one to more easily clean and round the tip's edges.
As the tips wear they get thicker and this can change the amunt of power required to achieve the same welds, So keeping the tips the same size and shape is good for consistency.
If using copper sandwich, I'd recommend just skipping using pure nickel or nickel plated steel and just get 304 stainless. Less power is required, the tear off strength is very good, sparking is minimal, and the electrodes provided do not stick strongly to the welds.
The Flux is a great Aid too, and if using thicker than 0.2mm copper one should consider it necessary, for consistency and for reducing the power required to achieve a solid weld and reduce the heating the inside of the battery cell sees..