Oh I missed that. I’ve never tried using that before
In general, if the ‘visually looks good’ range is within 15J, is it better to be at the top end or the bottom end of the range?
Thanks
if you are sure that this is 0.2mm nickel, then this suggests that maybe the calibration result is off. Please repeat that, make sure that the tips are clean (sand off), push the tips together hard during the SHORT step with -no- other metal inbetween them. If you get sparks, repeat.
its 0.2mm nickel plated steel. (less energy required)
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How’s it going did you make the targets? Or any new in testing things to work around?
i’m down to get one wjenever it comes around 
How quick and hot are you comfortable getting with the kweld? I can weld every 2 seconds but I slow down as my battery wires get too hot to hold.
Does the welder shutdown if it gets too hot?
I weld with about a 0.2-0.4s delaywith about 0.2-.6 seconds between each weld for about 50-70 welds at a time, basically til the probes get too hot to hold
the wires I don’t pay attention to
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How many joules? I’m doing 30 on one side n 40 on the other of A123 cells.
I’ve heard of people pushing the kweld much harder than I’m doing but definitely don’t want to damage it and be held up. I think my battery 10 awg wires are the bottleneck.
you do different for each side?
around 34 for the first tab
if i have tab to tab i do around 36
Yea the A123 green cells are aluminum and hard to weld the positive (bottom). 30 joules for one side and 40 for the other and still doesn’t stick as well
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then up the J 
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I wonder if cleaning them really well might help? I know soldering aluminum really requires strong acids to get through the oxide layer.
Really all welding is the cleaner the better but aluminum tig and mig need a lot of surface prep but nothing like the acids for aluminum flux soldering. Making a LFP pack for an old boosted or something?
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297 cells for a motorcycle. The safer hobby.
I cleaned them with alcohol but have welded so many over years and it’s just how they are. Actually the backup power supplies I get them from (batteryhook) or on eBay, all have a poorly welded side where they didn’t use enough current.
Earlier I made the same exact bike with high energy density LG m50lt cells, fitting almost the same exact battery dimensions (10x10x8.5”), and was6kilowatt hours and it’s 2.5kilowatthours with the A123
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Spot welding to aluminium is near impossible. From what I can tell, those a123 cells are indeed an aluminium casing, but have a nickel plate laminated to the positive terminal.
Even welding nickel that is directly on top of aluminium does require much higher welding energy though in my experience. I assume its because the aluminium absorbs a lot of the energy
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oops plz delete
Interesting I ran 2 of them in parallel and I got the xt90 and cables over 70deg battry and probes below 40 deg. (I stop let cables cool down when I can’t hold them)
Every one says I was wrong and probe get hot first not battry cables and connectors.
I use genuine xt90
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yes, it will inhibit pulsing until there has been enough cool down, typically a few seconds.
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I will definitely try welding these cells with the new kWeldPro, in the hope that the greater current (around 3500 amps) will help achieving this. Will keep you posted! (At the moment we are building 20 prototype units 
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How did u get on?
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