Sunkko 709A VS 709AD

[MK2R]

Hey. I am looking into getting some welder for building them battery packs, for some reason i found this sunkko welders, and thought maybe it's a smart idea to get the model that comes with both a soldering tool and a handheld spotwelding pen.

but here is the thing, i saw a video of someone using the 709A welding pen on a 120V outlet somewhere in the states, and that welding pen didn't perform well at all, but i don't find any good video or tests vs the A and the AD version, so is there someone out there that knows which one to get? I live in europe and we run 230V at home.

I am looking more into using the welding pen, to me it seems like u have more control then, and if you build a big battery pack i don't think holding each weld point up to the machine is going to be very viable when u work with a 1-2kg battery pack.

which one should i get and why in your opinion

 

[jonyjoe303]

All the sunkko welding pens I seen use that cheap thin gauge copperclad wiring. To get good welds you would have to make your own probe cables using 6 gauge pure copper welding cables.
The problem with copperclad is that it gets too hot to hold after a few welds. You can find videos on youtube where they replace the pens welding cables on the sunkkos to get better welds.
I use a 12 volt tab welder and had the same problems, when I replaced my probe cables with pure copper, it was huge improvement. It lets you use lower power settings which keeps the cables cool, it would be especially helpful with the AC welders, lower power setting will keep you from tripping the circuit breakers.
I was looking at the prices for the sunkko709ad thats over 300 dollars. Since you plan on just using the welding pen, I would seriously consider getting a 12 volt welder, they are in the hundred dollar range (malectrics) , I'm using mine with a 16ah odessey agm. 6 gauge Pure copper welding cables is about 20 dollars, and you can make probe tips from copper nails which you can buy a bag for 5 dollars.
Spending 300 dollars for a device you only use rarely is a big investment plus the sunkko takes up alot of space. I see too many videos on youtube of people making making modifications to make them work better. For 300 dollars it should work good right out of the box.

Old version of malectrics I have with 6 gauge pure copper welding cables. Power setting goes up to 9.9, I rarely go above 6.0, this welder has power to spare. When not in use stores easily. The new version of the welder is a major improvement with dual pulse and has a better screen and will even work off of a lipo battery pack. I had this welder for 3 years and build many battery packs with it both 18650 and lifepo4, I havent upgraded because I rarely use it and this welder even though primitive still does the job extremely well.

 

[MK2R]

Okay, so it's not nessessarely that you need the A or AD, the problem is with the welding pen.
I just bought myself 100 cells, Samsung ICR18650-26J, tested in the range 2400-2500mah each, still waiting for the delivery, but no stress, i still need to decide what bms i shall run with it along with the applications i am intending to use.

I might look into something like this to start with, i am sorry that the advertisement is in swedish thou. but i guess the pictures can speak for itself of what it is
https://www.tradera.com/item/301808/452460211/12v-punkt-svetsare-for-18650-26650-32650-batteri

It seems simple, and i guess u need to test your way of what current is optimal for your current weld. it can be ran by a car battery of the medium-higher AH range, or it can be run by a 3S battery pack (unclear of what kind of bms thou in regards of max current out)