Super glue nickel strips to 18650?

helpfulguy

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Tldr; Can you adequately reliably superglue nickel strips to poles to make battery pack?

Bear with me, novel mood, so bare with us:

In my possesion:
  • 100% lack of spot welder and equal amount of patience
  • Broken regular welder from around ww1 (seriously, bakelite, no components, directly to mains), with new in transit
  • A microwave that I love as much as it loves it's transformer


I don't want to build a fragile pack and be stranded in the edges of nowhere. It don't need to be nuke proof but adequately reliable for a ice scooter starter battery.

I've had previous success on a pack I did for a power tool, super gluing nickel strips, after dremeling the surface of nickel and poles of battery. Fixation with neodiddlium magnets (first), then putting small amount of super glue on the edge of nickel, so it runs out along the side, and unavoidably some in under. Since super glue/cyanoacrylate is, unfortunately in this case, not conductive, I don't want it so much between strip and pole (those two words in close proximity for lulz). My brain cell worked this out = a spot weld have 2 microscopic guaranteed conductive points, the rest of the contact area is unknown - does it contact or is it air between? No one knows. But it apparently works good enough, even so good it is the preferred method. Then it should work maybe not similarly, but adequately, with super glue on edges. First I tried with epoxy but got messy and if you screw up you have to grind it down, inhaling epoxy dust is how you get banned at pearly gates for stupidity.

So, what do you think?
 
No glue.
 
helpfulguy said:
I don't want to build a fragile pack and be stranded in the edges of nowhere.
Then I suggest not using nonconductive glues that harden into vibration/flexing-fragile crystals that easily thermal shock. ;)
 
helpfulguy said:
So, what do you think?

Why not soldering? I mean with a high melting point soldering wire and doing it fast, without boiling the battery:)
 
Super glue won't work. They make conductive adhesive that would work at low power levels, but not something you could use on a bike.

No solder, no weld battery connectors:
https://endless-sphere.com/forums/viewtopic.php?f=31&t=87434&hilit=VRUZEND
 
amberwolf said:
thunderheart said:
I mean with a high melting point soldering wire

I think you mean "low melting point"?

No, i mean high melting point because batteries in the closed case can get very hot and the solder with low melting point can start losing their electrical characteristics. The higher the melting point is, the safer the contacts will be.

fechter said:
No solder, no weld battery connectors:
https://endless-sphere.com/forums/viewt ... it=VRUZEND

Thanks a lot for the link! Vruzend's way is a simple but brilliant one. The only disadvantage is the price.
 
thunderheart said:
No, i mean high melting point because batteries in the closed case can get very hot and the solder with low melting point can start losing their electrical characteristics. The higher the melting point is, the safer the contacts will be.

Just how hot do you think batteries can get before self-destructing? I guarantee you it's less than the phase transition temperature of any common electrical solder.

Amberwolf's point was that a low-melting solder is much less likely to cause permanent damage to the cell when it's used to attach a wire or strip.
 
Chalo said:
Just how hot do you think batteries can get before self-destructing? I guarantee you it's less than the phase transition temperature of any common electrical solder.

Batteries can easily reach 70-80°C out of the case. I'm not talking about phase transition temperature, i'm talking about losing electrical characteristics (and maybe physical too). Typical solders melt at 150-180°C and i believe they are not as good at 80°C as are the ones with higher melting temperature. Solder melting at 150°C would get softer at 90-100°C which can result in bad contact after some time.

Chalo said:
Amberwolf's point was that a low-melting solder is much less likely to cause permanent damage to the cell when it's used to attach a wire or strip.
I got it right, but my point is that if you do the soldering fast enough - there will be no damage to the battery at all, even if your soldering iron is at 450°C. But the best idea (imho) is the Vruzend kit (tanks again, fechter)
 
thunderheart said:
I got it right, but my point is that if you do the soldering fast enough - there will be no damage to the battery at all, even if your soldering iron is at 450°C. But the best idea (imho) is the Vruzend kit (tanks again, fechter)

Nope, look around. Some recent work by Micah Toll shows how wrong you solder guys are. Google.
 
tomjasz said:
Nope, look around. Some recent work by Micah Toll shows how wrong you solder guys are. Google.

Googling resulted in a lot of hits. Not sure which one you are referring to.

As far as soldering goes, it would likely be the least expensive route. I've built some fairly large packs soldering and had good results.
One method I've seen that makes a lot of sense is to use fairly small copper wire (like 20ga) to go from the ends of the cells to a much heavier copper bus wire that can handle the full pack current. The small wires require much less heat on the end of the cell to get a good joint. Since they're very short, there isn't a problem with heating or loss. This is similar to the Tesla approach.

And you want to use the LOW melting temp solder. If the cell heats during use to anywhere near the temperature that would affect the solder, you'll have much bigger problems.
 
This makes Sense. I Guess you can use multiple of the thin wires to spread out current/heat if you are worried. One thing I tried but my soldering iron too weak/broken, to pre solder the battery as well as nickel, then put the two together,heating nickel from above till they merge. Didn't work but think it should. And not so hot.

Version 2 idea, is to make a spot welder out of an old sla battery such as some guys did on YouTube. Like ave but originally from that other guy. But with a twist: use your own cells as power. Will work best if pack is mostly parallell which you can arrange temporarily, should work for everything except final assemble unless you have high current/high p pack. Not sure if they like the 200ms bursts of shortcut though?
 
helpfulguy said:
Didn't work but think it should.

I'm using liquid flux bought back in Russia, which provides an excellent grip in an instant.
p8054-2.jpg
 
fechter said:
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Googling resulted in a lot of hits. Not sure which one you are referring to.



And you want to use the LOW melting temp solder. If the cell heats during use to anywhere near the temperature that would affect the solder, you'll have much bigger problems.

Sorry, there ar3 a few flir videos. Here’s Micah, eBike school. https://youtu.be/byvr-dwwao4
 
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