XT 150 has 6mm bullets.
There’s a thread on ES which has some different approaches which may be worth a look
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I picked one of these up recently. Are you still liking yours?
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@DerelictRobot I did build only 3 packs with it so far. I can’t complain it does the job and welds are solid.
One thing I don’t like but also couldn’t figure out if it’s only my issue or everybody has,
Once in a while (like 1 out of 100) welds is way stronger than I set up the welder to.
It’s not that bad that it damage the cell, but on one of the probes the nickel is meld a bit more than it should.
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xt150 will get hot fast, you will be able to live with them but maybe take a look at a even bigger connector or use this type of a connector
It will be needed if you plan to go a little faster with less down time
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Have you upgraded your probe wires? My probe wires seem to be the only thing that gets too hot
Standard from the kweld store, i guess you use lower settings and weld slower
But I have 2 sets of probes on my kweld, so when one get hot i switch to the another 
I use 60J for 0.2nickel for nickel to cell and 70J for nickel to nickel
My battery wires would get too hot after maybe max 10 min of welding
Anyways you can live with the heat and the downtime, im recomending the connector above if you want to work faster and with less cool down time
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Yeah i rarely go over 30J these days, but after 5mins solid weld time i need to let the probe wires cool. Battery wires stay much cooler than the probes
Well at 30J I hope your welds are strong enough… 
Are you sure the welds stay on the cell and the nickel rips when you pull on it?
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yeah the welds are good. I go 27 on the positive end and 30 on the negative. I bump it up to about 35 for nickel to nickel on a cell.
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Holy shit that’s a lot! I’m in the 30j ballpark for .20. Removing the nickel deforms the battery…
@Acido you get less heat with the yellow ring terminals compared to xt150? I use those terminals in builds (usually the fuse on the discharge line) but always wondered how much current they can handle. Is it a lot better?
Depends on what size you use, my kcaps are connected to the welder with them and they stay almost cool
the xt150 would get much hotter compared
But if you dont get slowed down because of it no need to touch a thing that works 
Idk where you guys get your 0.2 nickel that can be welded with 30J lol, even the creator recommends 50J for 0.2 nickel
I get mine from nkon / indian supplier and I dont feel safe under 45J
Also its not nickel if you menage to deform the cell, from my experience nickel is way weaker than that
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I only use 0.15, haven’t gone any thicker yet
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My notes say 18j-35j works, I think I use 25j. My nickel is good! I test each roll I’ve gotten. The boss welder came with some steel strip, so I have a basis for comparison.
Here’s a p-group that a bms killed.
I try to use a fairly light touch. Maybe that’s the difference? Do you push down hard as hell? Either way, 2x joules difference is a lot! Official chart says 50j, but IIRC most people were using less.
Interesting, my notes for .25
20 light pressure ok stick
20 heavy pressure good stick
30 light-p great stick
40 med-p great stick
.30 to knife blade (-p is pressure, 2nd column is milliseconds 3rd is amps):
30 20 1125 light-p ok stick
30 22 1125 heavy-p ok stick
40 25 1145 med-p ok stick
50 34 1130 light-p ok stick
50 35 1130 heavy-p ok stick
60 43 1156 med-p good stick hot
70 50 1150 heavy-p great stick hot
And .30 to a dirty used cell:
50 bad stick
75 ok stick
100 good stick HOT
110 better HOT
120 better still HOT
Thanks for confirming the ring terminal stuff. I’ll feel better about using it in my boards more. I’m always annoyed at how the wiring takes over all the space, and 3 way splices…
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I find more pressure works better with nickel on nickel, moderate pressure for nickel to cell.
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As the welder measures the current by sensing the voltage across the MOSFETs, and their ON state resistance varies significantly over production spread, the absolute measurement accuracy isn’t very good. The bus bar mounting can also affect the reading, accumulating to a theoretical deviation between measured and actual power of +/-40%. Absolute accuracy wasn’t a design goal, repeatability is what counts.
On top of that, a poor calibration will cause the welding algorithm to make false assumptions of the power delivery into the weld spot, and you end up dialing lower or higher Joules to get the expected result. Most important details for good calibration (SHORT step):
- press the conical areas of the tips together
- press as hard as possible
- make sure the surfaces are clean
- watch that no sparks fly
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weird, i pulled on my cells like a maniac and didn’t menage to deform them haha the nickel would always break first
I think im on the higher pressure side…
Anyways if our welds are strong, no need to mess with them 
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Hey so my notation says HOT for 60j and 70j. This means, the whole cell body would get warm/hot after 1 weld on the negative side. This is why I gave up on .25mm and .30mm.
If you’re welding packs with 60j, maybe I should give it another go lol. I bought 1kg of each…
I pull 0.15mm gently same amount as it takes when striping cable at work and it rips the nickle.
If I pull it medium amount of force as if iv not cut throu enough insulation befor trying to strip the cable, use the same preserve on pulling double layer 0.15 and it bulges out the battry So guess I pull to hard.
Never been able to pull hard or like a manic by putting my foot on it like I do when striping large armoured cable.
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Good news for you guys in Australia and around: Andrew from hiketech.au is starting to sell keenlab products here! https://hiketech.com.au/index.php?route=product/category&path=111
He’s also working on introductory videos, and I’d appreciate if you’d support him by watching and recommending them (given that they are good - haven’t seen them yet 
His YT channel is: https://www.youtube.com/channel/UC7MuS242JIeOQYY_8V9U89g
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