The event is on East Pecos Rd is all lol
Ha! I didnāt notice that. Part of the origin of my nickname. Pecos bill is a folk tale from the az area.
Damn that looks nice. Are you using the magic paste? How strong are the welds? What thickness copper? I did try direct copper no paste no nickel/steel but for me those welds werenāt strong enough for my liking. I donāt have paste so am doing the steel sandwich but itās more tedious than what Iād hope for. That said the welds are really damn strong with the sandwich
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Magic paste for sure, did a couple tear off tests with .1 steel sandwich but it was so fiddly and hard to be accurate with my welds. Very good tear off though.
Im using .3 mm copper with paste and a single pulse at gear 400 with .3ms preheat on the awithz p60f welder. The paste is fiddly in a different way but seems easier to get it all lined up and clean welds. The .3 copper is very strong and i canāt keep from damaging the cell with 4 weld spots and a single pair of welds needs to be rolled off leaving most of the weld on the cell. These are rs50 cells.
I have to leave a 2mm space from the outside edge of the copper strip because it doesnāt dissipate the heat around the weld sufficiently closer to the edge and i had a burn through when the welder did a double pulse - still trying to isolate why itās doing that but the work around of leaving more clearance around the weld seems to be working well. A double pulse with enough surrounding material had very similar tear off so itās not ideal but not causing any issues.
i am sandwiching.1mm steel for balance tabs just because itās the only clean way i could work out - but dropping the weld power by half and getting very secure connection
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Also made a little jig to mark the copper to get my pattern accurate, the .3 is so thick without it i was struggling
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Iām making a cute little 10s1p Eve 40PL.
0.2mm copper with 0.1mm stainless steel.
I attach the stainless to the beforehand with a 002 gear pulse.
I scribe a circle with a sharpened awl for the10mm positive tab diameter and for the 6mm Spiral on can.
I attach the stainless to copper with gear 002 in the 6mm spiral, and outside the 10mm ring that I weld within on the positive.
Cutting scribing, positioning sandwich, and welding SS to copper is tedious, but then positioning the sandwich on the cell and welding that goes quickly.
I used the welding flux/brazing paste. Without it I need gear 520 to 580, with it I need gear 320 to 385. This is with the 14.6kw AwithZ P20B.
Stainless steel reduces the welder power required significantly, vs using nickel plated steel of same thickness. Just donāt think you can solder balance leads to stainless steel. SS is solder phobic.
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TIL
Wonder if thereās some sort of flux that can counter this?
Very strong acid flux and very clean surface will let you solder ss but it isnāt ideal. Absolutely have to clean up all the flux very well of it will corrode copper and nickel. Usually itās conductive but i havenāt messed with it in a long time. Also high silver bearing solder helps. The pure nickel or nickel plated steel seem to work.
i got a roll of nickel plated copper to test some connections with too. ill do more after i finish this pack
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Fluxes containing hydrochloric acid, phosphoric acid, zinc chloride.
Given that there is already copper in the mix here, probably no advantage trying to solder to SS.
Nice, sounds like you got it dialed in decently. I should get some of that magic paste to try.
Good idea on the 3d prints, I should do that too. Is the right 3d print to push the fishpaper into the cell grooves nicely? I canāt help but notice how nice the fishpaper conforms to the cell grooves in your battery pic
Thatās the tesa 51036 tape, high temp and flame resistant and a lot easier to conform to the cells. Then it gets some fish paper after welding where it needs more protection before heat shrinking
that block is for alignment - helps me get it centered up correctly on the template.
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Iām confused lol
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