18650 spot welding -how to- ULTIMATE REPOSITORY

Hi guys,

any recommendations for 10m of pure nickel (tested pure) 0.15mm strip? One in the first post is not being sold anymore.

Building my first battery and looking for advice. Looking for around 72V so i'm thinking 20S 5P or 6P. I've got the sunkko 709 spot welder. I'd prefer to use NCR20700A which are 3000 mah 30A. This pack will have 150A-180A so I need some hefty connections. I can purchase dewalt packs and get great price and have nickel plated copper tabs already welded then solder copper wire for connections but that's not ideal to me. Next option is .02x8mm pure nickel strips with copper wire soldered for series connections. The ultimate option to me is this copper grid with Nickel tabs already welded. If the copper grids don't fit and multiple need to be connected can I just solder them before hand?

riba2233 said:

Hi guys,

any recommendations for 10m of pure nickel (tested pure) 0.15mm strip? One in the first post is not being sold anymore.

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Nkon sells it.

Tom

Thank you, but it's currently out of stock.

Any recommendations from aliexpress?

riba2233 said:

Thank you, but it's currently out of stock.

Any recommendations from aliexpress?

Click to expand...

1 year ago I bought legit nickel from here

https://www.aliexpress.com/item/Thickness-0-2mm-Weight-1kg-Low-resistance-99-96-pure-nickel-for-battery-spot-welding-machine/32336236156.html?spm=a2g0s.9042311.0.0.umEoPb

and here

https://www.aliexpress.com/item/Free-shipping-18650-battery-nickel-strip-0-3mm-nickel-plate-18650-26650-cell-nickel-belt-Lithium/2050756060.html?spm=a2g0s.9042311.0.0.umEoPb

Great, thank you! 8)

riba2233 said:

Great, thank you! 8)

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Last year I ordered from 3 sources on aliexpress claiming 99.9% nickel, all turned out to be legit. That can change at any time if they change supplier or just oblivious as to what they are selling. Sretno.

Doctorbass said:

Mr Lowbank said:

Hi All
Have been mining the Endless sphere for information to build a new pack for my Bomber #127. Thanks to forum members for all the great information.

I decided against 20s14p as it would be a tight fit, weigh more and I really don't think I need the amps. I'm hoping for Sanyo NCR 18650GA Cells but Tumich is out of the GA"s!!. Will be installing Max-E controller and have crystalyte 5405 and 5404 motors.
I have a JP spot welder on the way along with all the other bits I think I might need. After taking onboard all the info about building batteries I have come up with the following design. I'm interested in any comments.
Cheers Jon

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Excellent design!

I agree to say that the current share between cells is perfect.

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This is a great design. Do the crossed sections need to be soldered where they cross or would the battery welds keep them in contact? I would presolder the x strips and copper braid X-X-X.

and that was the end of a sukko 709.

had to run it on full power to weld 0.15 and after about 5000 welds it finally gave up with a huge flame, one popped D16 in the distribution box and one entire house smelling like someone blew up a 1970's stereo by running the amp up to 11.
it was coming, i had to cool the transfomer with 2 fans to keep it cool enough so i could touch it, often it was too hot for that. i only stop welding when i could not hold on the electrodes anymore. otherwise building a 400+ cell pack would take weeks.
now i have to wait for the DIY arduino welder from malectrics because no way i am paying another 250 euro's for such a chinese piece of shit.

What is the size of that transformer? If you don't want to upgrade the guts of the Sukko, the transformer coil might be useful as an adjustable soldering rig. Pretty cheap and easy to make, once you have a transformer core.

"DIY MOT-based [home] Resistance Soldering Unit (RSU)"
https://endless-sphere.com/forums/viewtopic.php?f=2&t=89289

its basically even smaller then a microwave core. not really usable. considering the primary core blew up means it will need a full rebuild. no way i am going to put that effort into it.

and i already have a good 180W temp controlled soldering iron.

flippy said:

its basically even smaller then a microwave core. not really usable. considering the primary core blew up means it will need a full rebuild. no way i am going to put that effort into it.

and i already have a good 180W temp controlled soldering iron.

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Yeah I've got the same one burn up too. Right now I'm using this spot welder that has a blue case and it's transformer is about twice the size of the 709A. I can measure the size of the core when I get home later.

I saw that welder as well when looking for a replacement. But in the end i would face the same problems with overheating and popping MCB's that i went "frock it" and bought a battery based welder. Much more effixient, no more extentions from the breakerbox for the dedicated D class MCB i had for it.

And it was a lot cheaper. But i would love to see a few pics of the insides of that welder.

flippy said:

I saw that welder as well when looking for a replacement. But in the end i would face the same problems with overheating and popping MCB's that i went "frock it" and bought a battery based welder. Much more effixient, no more extentions from the breakerbox for the dedicated D class MCB i had for it.

And it was a lot cheaper. But i would love to see a few pics of the insides of that welder.

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Here you go, I have attached a pair of aftermarket probes to the spot welder.
The transformer is much bigger than the 709A

http://imgur.com/a/N8x5L

flippy said:

I saw that welder as well when looking for a replacement. But in the end i would face the same problems with overheating and popping MCB's that i went "frock it" and bought a battery based welder. Much more effixient, no more extentions from the breakerbox for the dedicated D class MCB i had for it.

And it was a lot cheaper. But i would love to see a few pics of the insides of that welder.

Click to expand...

Yeah I'm looking for a Battery/Capacitor Discharge welder too, one that can weld 0.20mm nickel. right now this spot welder can only do up to 0.15 mm.

This was how i used my 709A back in January 2017, when the transformer core was getting too hot to touch.

DVDRW said:

Does any of these 78X or similiar welders do 0.15mm nickel to 0.15mm nickel weld? Mine dont (220V version).
0.15mm nickel to battery is ok. So what silverish material is 18650 terminals made of? Attracts magnet so its not stainless steel. Not copper and nickel either.

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My 110v didn't and was told I should of got the 220v so I did. It did no better. It does .1mm//004" Nickle and 30AWG fuse wire.

Got malectrics welders now. Ver3 is nice and Marc is a great guy to work with.

yes i used the welder from him for a 200 cel pack and i like it. the only problem is that my battery is a bit too much i think.

i need to have it at 2~3ms at best because of the insane current my 60Ah lifepo4 pack (60Ah winston cells) can deliver. it's weird to need to have a more shitty battery in order to have more control.

flippy said:

and that was the end of a sukko 709.

had to run it on full power to weld 0.15 and after about 5000 welds it finally gave up with a huge flame, one popped D16 in the distribution box and one entire house smelling like someone blew up a 1970's stereo by running the amp up to 11.
it was coming, i had to cool the transfomer with 2 fans to keep it cool enough so i could touch it, often it was too hot for that. i only stop welding when i could not hold on the electrodes anymore. otherwise building a 400+ cell pack would take weeks.
now i have to wait for the DIY arduino welder from malectrics because no way i am paying another 250 euro's for such a chinese piece of shit.

Click to expand...

Are you running this on 110 or 220v? Reason I ask is I just ordered and received a 788H and I was hoping it would be more reliable than this. I havnt had a chance to test it yet because I am waiting on the electrician to wire 220V in my garage. I have heard a lot of people running these on 110 and having problems so I was just basically taking a poll.

i am running it on 220. you do need a heavy MCD (al LEAST a C rating) in order to prevent it popping the MCD when turning it on. or use a in line resistor and an bypass switch to control the massive short that the transformer creates when powering on.

i was running it quite hard, full power is needed to weld 0.15 decently (0.3 is impossible). and i only stopped when the electrodes get too hot too hold on. if you make big packs like i do (400 cells) then you need to keep going otherwise you will be welding days on end for a single pack. if you only do smaller packs and take plenty of space between welds and build some serious cooling into the housing (use 2 120mm computer fans) you can get it fairly reliable. it took quite a bit of abuse before it actually died. do get a proper triac on standby because the original fake chinese POS one will blow its arse out in the first week.

but now i am running the above mentioned malectrics as a replacement and that is built much better. as long as you dont kill it with some stupid overpowerd battery like i did by accident (and part by a slight design issue that has been fixed now). that said: his support is awesome. within 3 days i had replacement parts. if the 788 dies then i recommend this one as a replacement.

Just some interesting videos here:

[youtube]4u2ZgFRosoQ[/youtube]

Pure nickel strip confirmed!
Worlds cheapest?

i orderd this one:

https://www.aliexpress.com/item/0-15-x-8mm-1kg-roll-Pure-Nickel-Strip-99-96-for-battery-spot-welding-machine/32817896871.html

8mm wide and costs 59 USD. the 8mm fits better on most square spacers and if you need to overlap. it can also carry 15% more current.
when i get it i will fo the test and report back.

Just had a scary moment building my monster 2.5KW pack for my Stealth Fighter.
I had turned the pot up pretty high and getting some decent strong welds, probably a bit on the strong side, but not too extreme. I was on my first layer of nickel which is possibly where I went wrong turning it up this high.
Anyway, I welded the negative terminal of an 18650 and it instantly sizzled (but only for a fraction of a second) with some clear liquid coming out of where I had just welded. At first I thought it could just be some left over alcohol from the cleaning I do with isopropyl alcohol wipes just prior to welding, but after wiping it away, more reappeared and I could see it very slowly seeping out from underneath the point I had just welded!
After wiping it away a few more times, and smelling it, I realised it was the batteries electrolyte leaking out
The cell wasn't getting hot and it was one row in from the edge, so I carefully, but quickly cut the already connected nickel and pulled apart just enough cells to pull that one out. Replaced it now and re-welded in some more nickel and everything seems ok.

Anyway, I hope that serves as a warning to all, not to crank up the power too high with your spot welder just cause you can. I think especially when welding the first nickel layer that directly contacts the cell and especially on the negative side, you want to only give it the power it needs...nothing more.

Cheers

Hello. I'm new to ES and pretty new to 18650 technology. I'd appreciate any feedback on a project I'm working on. I am trying to spot weld 18650 cells using a 12V car battery (45Ah, 325CCA) as a current source. I have a Nano controlling pulse length and have verified accuracy with my oscilloscope. I'm using 0.1 X 8 mm pure Ni strip. I'm using 3 mm dia copper welding electrodes with rounded tips, 1 mm flats. After several trials, I think a dual pulse of 50 ms / 100 ms separated by 0.5 s works well. I've been putting considerable downward force (~10 lb) on the electrodes. Does any of this raise a red flag?

Until I have something I consider sufficiently reliable, I've been working with a piece of 30 gauge nickel plated steel to simulate an 18650 can. A problem I've had, and the main reason I'm posting, is that occasionally I get a dramatic result in which sparks of molten metal are thrown out six feet in any direction and I have a hole punched in the Ni / substrate. Inspecting the electrodes, I find a piece of Ni/substrate welded to one. Do you think this could be due to uneven force / inadequate force? Are there any tips or techniques that can be used to reduce the risk of this happening on an 18650 cell?

Finally, I am using a wood support under my metal substrate, and I note significant burns on it -- trying to replicate this effect by placing my soldering station tip on the wood for a second requires a tip temperature in the range of 700 - 800°F. Does this sound normal? I'm somewhat concerned about attempting this on an 18650 cell as things stand.