A quick search reveals aluminum oxidizes in pico seconds, but perhaps a scrub and wipe will reduce the thickness of oxide layer that one is trying to weld through.
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These are b-grade cells (suboptimal CDR) so Iām likely going to go for it at this point.
How easily does the nickel strip peel off the cans leaving behind those dots, compared to the + side where it tears the nickel?
There looks to be no can deformation, which is difficult to avoid in my limited experience spot welding to steel cans and rolling the strips off.
The negative (flat) side of the cans deform when the nickel gets pulled/rolled off.
Less so on the lower end of this range
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Bought this a few times already. Just pick 70mm as your width. Fits 21700s perfectly and shipping to USA took less than 10 days
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I just ordered a few of these empty powerbanks to make use of some leftover cells. Except all my cells arenāt button tops, so Iām not sure how they will work. Has anyone tried something similar? Any solutions to improve contact if itās lacking?
Hereās the powerbank shell I ordered.
DIY Box-Case 2x 18650/18700/20700/21700 Battery Powerbank-Shell Micro / Type-C USB Dual Port with LED
https://a.aliexpress.com/_mrLYAS0
My tailight on Step Bro stopped working, as i was replacing it, it rattled a bit so i thought i should have a lookā¦
Had a little more going on than id suspected
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Mmmm spicy pillows. Iāve heard that this is where they get the lava they put into pizza rolls. Nice catch though - should be an easy replacement since you caught it before anything too bad happened
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Wow, glad you caught that!
LiPo flames would make a great taillight but an expensive one. 
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Can someone please explain what has happened to this battery? Has it vented? Leaked? It looks a bit toasted and the wirings coocked but it hasnt actally gone into TR?
No sign of cell puffing so Iām doubtful it went into TR but that certainly looks like it could be corrosion from the lithium salt in leaking electrolyte. The electrolyte is mostly organic solvents so it might have dissolved some plastic too, creating some/all of the black deposit.
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Is there a sickly-sweet, distinctly solvent-type odor at the black end of the cell? If so, that would probably mean the cell leaked and should not be used.
The liquid is toxic and flammable so it will need to be cleaned up carefully.
I didnt think to inhale or taste any of the residueā¦ i was too busy being horrified by the whole mess.
i hadnt considered using the cellā¦ i find it astonishing that someone might given its condition.
Edit: is this sort of thing just ok to take to the local hardware store? They have a bin to put batteries in but seems a bit dangerous to blindly throw it in with a whole bunch of other little bombsā¦ also wonder if theyāll take it if you tell them its suspicious?
My method for hardware store bins is to discharge them waaayyy down, tape the terminals, then bag them. But Iāve only dealt with round cells that are physically intact, I wouldnāt like to find out what the leaking solvent would do to a plastic bag. Hopefully someone else has a specific answer about a container thatās safe for the job, Iām assuming steel given thatās used for round cell bodies but the active chemistry is different here so idk if the solvents are too
On the bright side it doesnāt seem like yours has a lot of energy in it, but I also wouldnāt like to try discharging it if it does
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@Evwan do you remember if you used 42J on both ends, or just the positive terminal? I donāt think itās a kweld problem - I am noticing the same behavior
Both ends
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Got the new v4 maletrics spot welder. I seem to be doing fine with 0.15mm strips but for some reason not getting a reasonable weld with 0.2mm not matter how high I set the ms. Anyone have an idea what Iām doing wrong or whatās going on ?
What battery?
@Evwan the ones recommended for Lipo
Hobbyking: Turnigy nano-tech 5000mah 3S 65~130C Lipo Pack w/XT-90
I have (2) of them, will connecting them into parallel help?
Got 2 for when one of them dies I can continue.
Yes run them in parallel
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