kWeld - "Next level" DIY battery spot welder

[BVH]

My Sunkko is long gone. Was gone soon after the Kweld arrived.

[Compoundbike]

How to best describe the difference

I did multiple welds to 0.15mm nickel with sunko and prayed afterwards that even one of then would hold. With kweld every single one is constantly strong and I need pliers to rip off the nickel and it tears of around the weld points leaving the welds and rest of the nickel still attached to the cell.

I have the cheapest possible sunko welder so I had it at maximum settings and kweld beats it even at very low energy levels. (10j)

just ordered one.. cant risk disconnected batteries.

[Headrc]

Ossivirt ...so 50j and you got good welds for .1MM nickle plated copper? With the regular electrodes? I now have some .15mm nickel plated copper so it sounds like I would have to even use a higher setting .....

[ridethelightning]

i think he was talking about straight 0.15 nickel. if you find 0.15 nickleplated copper, let us know!

i have doubts about it though. its used in power tool packs, but when i tried welding it, i think the nickle skin vapourises causing issues, as you need so much current for the copper, the nickle has high resistance and poof!

[ossivirt]

Ossivirt ...so 50j and you got good welds for .1MM nickle plated copper? With the regular electrodes? I now have some .15mm nickel plated copper so it sounds like I would have to even use a higher setting .....

I used just bare copper. I tried plating it also but did not receive any benefits for welding. Needed same current and welds did not get any stronger. Maybe my plating was too thin or something.

i think he was talking about straight 0.15 nickel. if you find 0.15 nickleplated copper, let us know!

i have doubts about it though. its used in power tool packs, but when i tried welding it, i think the nickle skin vapourises causing issues, as you need so much current for the copper, the nickle has high resistance and poof!

I noticed this also. Nickel plating got burned black and maybe little vapor too.

[ridethelightning]

btw, nickel is toxic as

[Headrc]

I do have a sample of some .15 nickel plated copper ....and it is available but not cheap. But useless to me unless I can get good welds with it ...which is why I asked. I tried some at 25j with the stock electrodes and the welds were not good. I will have to try a higher setting or different electrode material to see if I can get good welds. Which is why I asked if anyone has done it to see if they could suggest the proper setting.

[ossivirt]

I do have a sample of some .15 nickel plated copper ....and it is available but not cheap. But useless to me unless I can get good welds with it ...which is why I asked. I tried some at 25j with the stock electrodes and the welds were not good. I will have to try a higher setting or different electrode material to see if I can get good welds. Which is why I asked if anyone has done it to see if they could suggest the proper setting.

I think you need at least 75j depending on your battery amps and other things likely even more..

[ridethelightning]

try making some tungsten tips.
1.5mm tig electrode,(use non radioactive zirconium ones ) drill a hole in copper rod with drill press, slowly bit by bit, use oil. press fit the electrode in, cut off excess with grinder(i make mine~10mm long.
ball the end with the grinder or sanding machine etc.

[Compoundbike]

Quick update I received my K-Weld after few welds liquid came out. First i thought this was Water from previous use but turned out it came from the "Lanzhd" Cell.
I had the setting on 9.5 Joule automatic
However i reduced up to 2.5 Joule and worked better.

I measured the Cell voltage and still seem to be good, should i be careful with the leaked Cells?

[ossivirt]

Quick update I received my K-Weld after few welds liquid came out. First i thought this was Water from previous use but turned out it came from the "Lanzhd" Cell.
I had the setting on 9.5 Joule automatic
However i reduced up to 2.5 Joule and worked better.

I measured the Cell voltage and still seem to be good, should i be careful with the leaked Cells?

When electrolyte comes out and air gets in the cell should be disposed of. It might hold voltage but likely it will have lower capacity and it will age quickly. There is also concern about fire-safety..

Electrolyte smells horrible, you cant confuse it with water..

[flippy]

if it leaked you need to toss it immedialy out. i mean litteraly out the door.

[Compoundbike]

Is that normal that the K-Weld can burn through the Battery that Electrolyte comes out? Probably Not.

So has this happened to Someone else?

[ossivirt]

Is that normal that the K-Weld can burn through the Battery that Electrolyte comes out? Probably Not.

So has this happened to Someone else?

New firmware versions have anti arc features that reduce the risk of puncture but it's powerful and capable device so with too much energy it melts through. That's why it has adjustable output

[Compoundbike]

Yes but like i said 9,5 Joule after Calibration had enough power to burn.
Tomorrow i will do more welds with 2,5 joule on 0.15 mm Nickel. Besides that everything is fine.

[Merlin]

what power source(battery) do you have?
and how much amps does kweld show on calibration?

[flippy]

Is that normal that the K-Weld can burn through the Battery that Electrolyte comes out? Probably Not.

So has this happened to Someone else?

That has nothing to do with kweld, any high power welder will puncture cell walls if set too high.

Even a crappy aliexpress welder can do that.

[Merlin]

with 2-10J burning holes in a cell?
i played around with 130/150J and wasnt able to shot a hole in a cell.(2000a on calibration and 1700 on real welds)

post some pics of your 2-10J welds please.

[Compoundbike]

Okay how should I say.. First there's a touch with some sparkles after that there's a good weld with nickel plate melting, but at the same time liquid is coming out.

*edit* also twice a small flame came out.



https://i.ibb.co/sqVjjyQ/IMG-20190609-121130.jpg

[Merlin]

holy cow. stop trying anything and get in contact with frank.
theres something wrong.

that looks more like 250J to me.

the heatshrink on the upper cell is melted/shrinked (!)

every cell your tried i would not use for a battery pack. sort them out.

thats 30J :

[Compoundbike]

Battery source is the recommended 3s 5000 mAh from Hobbyking.
.

Okay i will try something else, if it doesn't help i will contact him.

[ossivirt]

Okay how should I say.. First there's a touch with some sparkles after that there's a good weld with nickel plate melting, but at the same time liquid is coming out.

*edit* also twice a small flame came out.

That looks bad. Under 20J there should not be any burning or discoloration with 0.15mm nickel in my experience. Can your calibration be that badly off? What condition your probes are now? all burned and black or nice clean copper looking? Is your fuse turning black or does picture just have some shadows there?

Only time I have burned hole through is when I accidentally double tapped foot switch and fired 2 pulses in a row at the same place. Sometimes when electrodes are in bad contact and/or burned black it makes sparks and arcs and that can also make holes and is little scary..

[flippy]

Okay how should I say.. First there's a touch with some sparkles after that there's a good weld with nickel plate melting, but at the same time liquid is coming out.

*edit* also twice a small flame came out.



https://i.ibb.co/sqVjjyQ/IMG-20190609-121130.jpg

that is not 2J, that looks like 200J+.

either your callibration is wrong or your battery supply needs attention.

[Compoundbike]

Okay i found the problem. I had calibrated(shortcutted) through a nickel stripe which caused the problems.

Maybe the inventor should put up the warning, so any other people shouldn't pay "learning Money" by making stupid mistakes like me.

I have punctured about 10 cells.
HbPowerwalls video helped me, to get the idea where the problem could have been.

[flippy]

The instructions the come with the kweld are pretty clear i have to say.....