im waiting till black friday. these defiently go on sale during black friday week. they will be like half the price.
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me too now that you mentioned 
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I’ll chime in again and say a lot of people are using these happily with single lipos for welding up to .20mm nickel. Thicker nickel, and copper, seem to stress the system as a whole (cells get hot), and seems not worth pursuing. I don’t think getting more than 1 lipo pack makes good return on investment if you’re building packs for just yourself.
There is a path worth investigating though, sandwiching copper with nickel.
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I was going to say making the lipo investment might as well be a working esk8 Battery too.
So 4x 3S 3Ah For $170 let’s call it $140 sale price.
Use 2-3 for welding. All for esk8.
To be honest if I was only going to build 2-3 battery’s and I was set on the 3S3Ah battery’s because I would use them for some thing else. then I personally would buy only 2 it would work fine and if you build more than 2-3 you could expand the system later by adding more as i start getting faster welding after my 2nd built Battry.
I started with a 6Ah battery and I checked it a lot and was cutting Nickle in between welds and it only warmed up a little bit wasn’t until the 3rd I stoped a few times to let every thing cool down as as it was getting to warm for comfort because by then I got faster. IMO 1200amps is a good amount and I was getting that easily from a 6AH battry giving me 1400-1600 if I remember correctly. rember this is only my opinion you could be quicker and more never hurts untill you exceed the 2000a limit of the Kweld
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Just got my Kweld in the mail and assembled most of it tonight. I’m really interested in playing around with different tab materials.
Nickel’s cool and all, but has anyone tried welding nickel plated copper? I still need to find a source. IIRC the main problem with copper is it fuses to the electrodes more readily, but maybe a nickel coating would help. I’m quite unsure of the welding characteristics of these specific electrodes.
It should also be possible to use tungsten electrodes if you guys really want to get fancy with copper. Unfortunately the only copper spot welders I’ve seen also implement a shielding gas.
Anyways, why don’t lead acids get some love in this thread, I haven’t seen one during my gloss over. I was planning on using a fat one since it’s safer than lipos. Any particular issues with this?
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I haven’t seen that, how about you get a nickel plating kit, make some & be the guy for a week or so 
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These results worry me a bit, not sure if Hobbyking is doing the right measurements for us. Most importantly the test frequency (ESR is a function of frequency). I did own measurements with my red 3S/6AH/65C Graphene that is no longer sold, and got significantly lower ESR than the 9mOhm of the Graphene Panther 3S/6AH/75C (that’s the closes match). I can’t find my notes but from memory it was somewhere at 4 to 5 mOhms. I trust my results as I am using a precision current shunt along with my 300MHz oscilloscope to record the current and voltages during actual welding pulse.
I should probably purchase one of the newer models and repeat my analysis. My preference would be that mentioned model, anyone having another suggestion? If you want to be on the safe side, my original recommendation is still available for purchase: https://hobbyking.com/en_us/turnigy-battery-nano-tech-5000mah-3s-65-130c-lipo-pack-xt-90.html
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Hmh, so I just got mine setup and running.
Went through the setup procedure. Looks like I scored a really low mR, 1.68.
If 2.2-3.0 is typical, are there any chances of complications from a lower value? Manual isn’t quite descriptive.
I was using one of these and it got hot quite quickly, two in parallel works beautifully 
Which one? The forum seems to have deleted your referral.
EDIT: found the button. This one, right? " Turnigy Graphene Panther 4000mAh 3S 75C Battery Pack w/XT90" How many amperes do you get with one or two of them?
That’s a too low reading. The current probe design usually is at 2.1 milliOhms, Do you have the stock probe system with original cable lenghts (0.8m round trip on the output side)? The current measurement relies on good contact between the bus bars and the PCB, maybe you can try some cleaning (fine sand paper) of the bus bars. Also check that there are no burrs or other debris between them.
I thought a bad connection would result in a higher resistance been a higher value. In my understanding flattening and cleaning the bus at would create a better connection reducing the value of resistance creating a even lower value. What am I miss understanding?
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My kit looks to have only came with one cable. I think I must’ve mistaken that for a 1M long strand, as the assembly guide says to use 0.2 and 0.8 for the segments. After splitting it my output leads are only about 600mm round trip.
While I realize the mR value on mine is quite low, is this particularly an issue? I did notice that occasionally during the setup measurements it can go into the 2000A overcurrent protection, but it still seems to get good values when this doesn’t happen. I’m assuming that since it’s on the cusp of 2000A when the probes are touching, that it won’t exceed that when welding nickel which would add additional resistance.
It’s not that simple, because there are 6 MOSFETs in parallel that are bridged with the bus bars, and the voltage is sensed across one of them. If that one carries less current than the other 5 because of a bad bus bar contact in this area, then the voltage across it will be lower and the unit thinks that the current would be lower.
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The intended lenghts are approx 0.1m + 0.1m for the battery pieces, and 0.4m + 0.4m for the probe pieces, totaling 1.0m. If you have cut the wire otherwise then this is absolutely no problem (except that you now have shorter probe cables to deal with), and the unit will adapt via the calibration. But this explains why you get a lower resistance: your probe cable is shorter.
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When I çlicked on this thread this reply wasn’t there and when it loaded it was. Weird timing.
Was about to post that my KWeld has whipped across the world and will arrive tomorrow!
Made sure I wasn’t broke in case of duties. Lol
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Just two of them get also the job done? Because the 6Ah one are on backorder with no ETA.
@tatus1969 Waiting on my order… Hurry up!
Just kiddin’. 
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1 has been used and works 2 inparallel would be better.
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120€ is a lot. One costs 60€. I’d like to cap my spotwelding equipments to 300 max.
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