Soldering 18650s

Hey guys- I’ve built my own packs using 18650s, nickel strips and copper wire soldered to bolster current across the nickel strips… but i see a lot Of people using copper braid instead of the nickel or copper wire I’ve used. Is that sufficient for series and parallel connections? I’ve read a LOT on here and on endless sphere… still not sure what to believe. Also, can you get copper braid on amazon reliably? And if you purchase the tinned copper braid is it an easy solder? Cheers all!


You don’t really want to use generic copper braid as that’s likely not rated for current.

If you use it, look for “copper grounding strap” and try to find a reputable seller that will give current ratings to their various guages. Using the real deal is no problem at all because it acts just the same as a wire.

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Short verision: Does it have low resistance and can handle alot of current? use it. Aslong as you can attatch it to your cells without making any harm

copper braided wire carries less amps than regular solid copper wire, which is even easier to solder

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but muh flexibility

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I guess that’s kind of what I’m getting at… how do you build flexible packs with rigid components? I’ll do some more searching online. Thanks, all.

Well most use some sort of wire to connect the P groups, see a pack like this image

Or you could do some sort of Bridging with the Copper Braiding, but just make sure that if you buy a part we havnt linked or anything, that you ask us so we can make sure you wont make something crazy happen


Solid copper wire for paralel, 10-12awg for series

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If you do 12g Wires, do you need the nickel strips beneath?

Normally battery packs are spot welded with nickel strips some people solder their batteries and they use copper some people only spot weld parallel connections and then use wire for series connections decide And theres probably even more ways to make a battery pack

since your going to solder your battery packs, i would recommend to get those battery pcbs and some fuse wire and build your pack that way

Also putting nickel under copper wires does not make much sense

Can you spot weld to copper?

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So, I’ve done nickel strips before, and laid copper wire on top of it. You’re saying that doesn’t serve any purpose? Maybe it’s just a waste of time…

I think he is trying to say that nickel isn’t a great conductor of electricity. Copper or other materials are far better. But having a layer of nickel before the cell is definitely better for it so it doesn’t get heated up as much

You can spot-weld nickel TO copper with a standard spotwelder. However spotwelding directly with copper requires special tungsten electrodes. Your normal copper electrodes will fuse to copper if you try it.

Would steel also fuse?

You shouldn’t use steel since it’s a bad conductor. But also, steel will weld quite well. Unfortunately there will be large sparks and some slag.

So it would weld the steel electrodes to the copper or it would weld the battery to the copper?

No hands on spot welding but have read, here I think, that copper is difficult to spot weld too because it’s so conductive you need to get very high current to heat it up enough to melt and make the weld, sounds reasonable to me. Soldering is always less ideal because of heating the cells though so seems no ideal solution.

Interesting vids here on feels battery design second one goes into the choice of using cylindrical cells… Seems they use something like pro version of vruzend or NESE

What if I get some 0.2mm copper sheet, a 900A+ car battery, some jumper cables, and some iron nails? Possibly best battery or guaranteed death?

Worst battery. You’ll just melt your steel electrodes, you need to use tungsten ones.