heltec SW01H spot welding tesla 21700 aluminum positive pole

sameh.d

10 mW
Joined
Jan 14, 2024
Messages
32
Location
middle east
salvaged one pack of tesla model 3 21700 cells. positive side is aluminum and hard to spot weld.

heared about kwed spot welder and group here but not much info regarding sucess with those tesla cells.

i ran into heltek SW01H where the h version is for pure nickel strip to aluminum pole of lipo batteries.

any ideas if that will work with the tesla 21700 positive side?
link to the spot welder if that is o.k. with admins.
https://www.aliexpress.com/item/1005003985025837.html?spm=a2g0o.detail.pcDetailTopMoreOtherSeller.11.1beeQUhWQUhWsN&gps-id=pcDetailTopMoreOtherSeller&scm=1007.40050.354490.0&scm_id=1007.40050.354490.0&scm-url=1007.40050.354490.0&pvid=1d891901-f412-4f26-90ad-25f19642f9ca&_t=gps-id:pcDetailTopMoreOtherSeller,scm-url:1007.40050.354490.0,pvid:1d891901-f412-4f26-90ad-25f19642f9ca,tpp_buckets:668#2846#8109#1935&pdp_npi=4@dis!ILS!629.05!534.71!!!163.03!138.58!@212a6a4e17235501507831785e7836!12000027643080364!rec!IL!130708247!X&utparam-url=scene:pcDetailTopMoreOtherSeller|query_from:


thanks
sameh
 

Attachments

  • heltec.png
    heltec.png
    405.8 KB · Views: 18
Last edited:
I'm on the same mission here. I have roughly 1 bazillion Tesla 21700 cells in possession with the same obstacle. I've looked for info in the past month or so and haven't seen anything confirming a way. I purchased a Glitter 811H welder specifically in hopes for this to work. The Glitter brand from what I can tell just seems like a different branded version of the Heltek welders. I went for the big boy, just to be sure there was no lack of power, and it certainly doesn't lack. I think the 801h would have been sufficient, but I can't confirm. On the 811H, anything over 30-35% power seems to destroy the positive electrode causing the gas to slowly bubble out of the cell, but won't weld to the nickle button caps I'm trying. I can't really confirm they're even pure nickle, as they're from Aliexpress, so take that with a huge grain of salt. I've scuffed the aluminum up with a dremel and have been successful getting some of the caps to weld using around 45-50% power, but then they just get damaged and gas up in the process. I don't claim to be very educated in any of this, so maybe there is some type of flux to try or a better technique. As I get extra time, I'll try some different gauge nickle strips at different power levels and see what I come up with, but I'm pretty discouraged so far. It seems the aluminum is just too thin for spot welding. Solving this would be extremely valueable to me, so I'm all ears to anyone with ideas. I'm willing to destroy all the cells it takes to figure it out.20240818_220902.jpg
 
anything over 30-35% power seems to destroy the positive electrode causing the gas to slowly bubble out of the cell, but won't weld to the nickle button caps I'm trying. I can't really confirm they're even pure nickle, as they're from Aliexpress
Have you tried Aluminum to Aluminum?
 
Great to see your reply although it is not encouraging news.
I Wasnot really aware of the 811 which is double the price of 801h but again it didnot solve your problem.
Would you think kweld may have different results?
By the way, i have bought those caps from ali express but with my diy single microwave transformer spot welder i dont have much expectations..i didnot try the caps yet but nickel strips were not successful.
Probably will try 2 mot's with pulse timer before deciding on a factory spot welder to buy. Kweld is option but i will wait to have better picture of what could work with tesla positive cap.
Not sure if i can find company with reasonable price that can laser weld or maybe ultrasonic weld caps to the positive pole of the cells.

I have kept part of tesla cells with the positive fuse wire just in case i may find a way to attach to it instead of welding but not sure my chances here are even better
 
I'm on the same mission here. I have roughly 1 bazillion Tesla 21700 cells in possession with the same obstacle. I've looked for info in the past month or so and haven't seen anything confirming a way. I purchased a Glitter 811H welder specifically in hopes for this to work. The Glitter brand from what I can tell just seems like a different branded version of the Heltek welders. I went for the big boy, just to be sure there was no lack of power, and it certainly doesn't lack. I think the 801h would have been sufficient, but I can't confirm. On the 811H, anything over 30-35% power seems to destroy the positive electrode causing the gas to slowly bubble out of the cell, but won't weld to the nickle button caps I'm trying. I can't really confirm they're even pure nickle, as they're from Aliexpress, so take that with a huge grain of salt. I've scuffed the aluminum up with a dremel and have been successful getting some of the caps to weld using around 45-50% power, but then they just get damaged and gas up in the process. I don't claim to be very educated in any of this, so maybe there is some type of flux to try or a better technique. As I get extra time, I'll try some different gauge nickle strips at different power levels and see what I come up with, but I'm pretty discouraged so far. It seems the aluminum is just too thin for spot welding. Solving this would be extremely valueable to me, so I'm all ears to anyone with ideas. I'm willing to destroy all the cells it takes to figure it out.View attachment 358367
Battery On the right, is it fluid? Are those gases coming out?
Have you tried shortest pulses when welding?
 
I'm on the same mission here. I have roughly 1 bazillion Tesla 21700 cells in possession with the same obstacle. I've looked for info in the past month or so and haven't seen anything confirming a way. I purchased a Glitter 811H welder specifically in hopes for this to work. The Glitter brand from what I can tell just seems like a different branded version of the Heltek welders. I went for the big boy, just to be sure there was no lack of power, and it certainly doesn't lack. I think the 801h would have been sufficient, but I can't confirm. On the 811H, anything over 30-35% power seems to destroy the positive electrode causing the gas to slowly bubble out of the cell, but won't weld to the nickle button caps I'm trying. I can't really confirm they're even pure nickle, as they're from Aliexpress, so take that with a huge grain of salt. I've scuffed the aluminum up with a dremel and have been successful getting some of the caps to weld using around 45-50% power, but then they just get damaged and gas up in the process. I don't claim to be very educated in any of this, so maybe there is some type of flux to try or a better technique. As I get extra time, I'll try some different gauge nickle strips at different power levels and see what I come up with, but I'm pretty discouraged so far. It seems the aluminum is just too thin for spot welding. Solving this would be extremely valueable to me, so I'm all ears to anyone with ideas. I'm willing to destroy all the cells it takes to figure it out.View attachment 358367
please find those 2 interesting videos for different methods: welding with deca alu 15 argon using argon and second one seems like a jewelry welder of some sort

deca argon:

second interesting technique -jewlery style? it is a russian product with russian review that i couldnot find parralel product on aliexpress unfortunately and not sure if that is really as it is reviewed..it says the MYSA 200 is analogue to the highly priced lampert microwelders:

and another interesting one using glitter 801 h with nickel aluminum strip, i would say partial success? maybe with scuffing and immediately spot welding using nickel aluminum strip where aluminum side is toward positive aluminum elctrode may be sufficient? i ordered nickel plated aluminum as in the video for testing purposes, it makes sense to me.
 
Last edited:
I don't beleive you can even adjust the pulse time on the Glitter welders, which is something I hadn't even considered, maybe out of ignorance, although I'll still get great use from it. Even if the kweld isn't near as strong, it may be strong enough, and from the bit I've read, it has way more options including multiple pulse settings. Dual pulsing apparently allows a less powerful initial pulse to acheive a small contact patch for the second pulse to not have to work as hard in making the actual desired weld, which helps in dialing in with less needed power as well... as I understood it. I spoke to someone from battery clearing house today (nice dude) that knew of someone using some type of flux and aluminim/nickel alloy strip and was able to get working results, although not exactly ideal. He couldn't confirm exactly what it was, but if I try anything out, I'll share what I find. I hadn't seen those videos yet. Maybe I can take something away from them as I try other things. Thanks much.
 
...and yes, the liquid in the picture is the gases coming out. I also haven't tried shaping my weld leads into different points, so that could be significant, as well as applying varying pressure. Honestly just gave it my first shot with what little time I had just before finding your original post when I got discouraged, so the good news is that I haven't put a ton of effort in yet. My screen name does not lie.
 
...and yes, the liquid in the picture is the gases coming out. I also haven't tried shaping my weld leads into different points, so that could be significant, as well as applying varying pressure. Honestly just gave it my first shot with what little time I had just before finding your original post when I got discouraged, so the good news is that I haven't put a ton of effort in yet. My screen name does not lie.
 
Hi
adding to confusion, i just recieved assistance from heltec support offering ht sw-02a as the recommended spot welder for tesla 21700 cells..i suppose glitter 811 is parralel to the better version which is sw02-H with internal resistance reading?
Anyway, i prefer to wait a bit..if you see videos i will be interested in your opinion.
Nice nickname b.t.w
 
The jewelry welder looks pretty solid as a next option. I'll eventually order some aluminum/nickel strip and try that first with the Glitter. I get very little extra time, so will probably be weeks before any results. I'll eventually come back with something.
 
Sandwiching with some other material to generate the heat would probably be your best bet. Aluminium is very tricky to spot weld with a very fine line between ineffective and vaporizing, it needs both huge power and very fine control. Iirc, spot welding 2 sheets of 1.6mm aluminium needs somewhere in the region of 20,000 amps.
 
The Glitterwelder.com web page info and video for the 811H explicitly mention nickel strip to aluminum battery welding, so it is strange that it wouldn't work. If there is no setting between 'no weld' and 'hole burned into battery', then maybe you need thinner nickel strips to weld to the thin battery shell.
 
If it helps... You are essentially welding. Welding aluminum with GTAW (gas tungsten arc welding - commonly called TIG). Possibility not suitable for cell tabs I realize, but maybe you can employ some or all of the requirements utilized.

Many grades of aluminum oxidizes extremely fast, especially in the presents of high humidity. Therefore, requires removing the oxides immediately prior the welding - don't dillydally. I use a stainless wire brush and acetone. The welding is performed with AC, and requires argon as a shielding gas.
 
Regarding oxidization: could it be that the outside of the cells was anodized, and has a thicker than usual oxide layer? Then you should probably sand that off just before welding (see post before this one).
 
Regarding oxidization: could it be that the outside of the cells was anodized, and has a thicker than usual oxide layer? Then you should probably sand that off just before welding (see post before this one.

Anodic coating is generally non-conductive, so I suspect they're not intentionally anodized.

This leaves me to wonder what the actual alloy content is, and why they chose to use aluminum.
I do have a box of 21700 model 3 cells I need to examine. 🤔
 
Just checked... my model 3 cells are ferrous (magnetic), not aluminum.
 
If it helps... You are essentially welding. Welding aluminum with GTAW (gas tungsten arc welding - commonly called TIG). Possibility not suitable for cell tabs I realize, but maybe you can employ some or all of the requirements utilized.

Many grades of aluminum oxidizes extremely fast, especially in the presents of high humidity. Therefore, requires removing the oxides immediately prior the welding - don't dillydally. I use a stainless wire brush and acetone. The welding is performed with AC, and requires argon as a shielding gas.
Thank you
Do you tig weld aluminum batteries or other stuff?
I am considering as well stud welding machine such as one of the videos.
Some reasonable price for andeli srs 160 stud welder on aliexpress
 
Regarding oxidization: could it be that the outside of the cells was anodized, and has a thicker than usual oxide layer? Then you should probably sand that off just before welding (see post before this one).
I am not sure about removing oxide layer. I am worried it should be the opposite in our case of spot welding.
I was told that in case of spot welding you do need the heat coming out of high resistance to get welding effect, so the oxide layer should help trap more heat. I was told that in case of tig welding the oxide layer will be an obstackle and should be removed.
So if that is true, is recommended scuffing for spotwelding was mistakenly brought from tig welding world? Maybe
 
Some update: finished building my spotwelder : 2 mots+time&ampere controller
some test results, shall i call it partial success?
0.15 nickel aluminum
 
The Glitterwelder.com web page info and video for the 811H explicitly mention nickel strip to aluminum battery welding, so it is strange that it wouldn't work. If there is no setting between 'no weld' and 'hole burned into battery', then maybe you need thinner nickel strips to weld to the thin battery shell.
I agree
But pay attention pictures basically show lipo prismatic cells that have much aluminum height, not thin sheets as with tesla-more challenging
 
Back
Top