18650 spot welding -how to- ULTIMATE REPOSITORY

[Skrzypas]

The subject of copper has come up dozens of times and the discussion always comes back to pure nickel. While ES has been the source of many great discoveries I think this has horse has been beaten to a pulp. Nickel just works.

Has anyone considered brass?
Roughly the same conductivity as nickel .. Corrosion resistant and cheap.
Edit: maybe the thermal conductivity is too high.. More than nickel but much less than copper.

Sent from my Nexus 5X using Tapatalk

Earlier in the thread I shared the fact that most of my battery pack is brass-tabs-based. I used 0.1 mm brass sheet, cut it myself with scissors. A sheet for all tabs for a few kWh pack cost ca 5$. But brass is weak.

 

[vince74]

Hi folks
Just to warn you about some 'pure nickel strips' that turns red after a day in salty water... You can see for yourself
https://www.aliexpress.com/item/Free-Shipping-18650-battery-pure-nickel-strip-18650-cell-nickel-plate-0-2-27-10000mm-nickel/32410705619.html
https://www.aliexpress.com/item/Free-shipping-nickel-belt-0-3-8mm-pure-nickel-strip-18650-26650-battery-nickel-plate-Lithium/32668168560.html
I have opened a dispute, will see how it goes.

 

[Offroader]

Hi folks
Just to warn you about some 'pure nickel strips' that turns red after a day in salty water... You can see for yourself
https://www.aliexpress.com/item/Free-Shipping-18650-battery-pure-nickel-strip-18650-cell-nickel-plate-0-2-27-10000mm-nickel/32410705619.html
https://www.aliexpress.com/item/Free-shipping-nickel-belt-0-3-8mm-pure-nickel-strip-18650-26650-battery-nickel-plate-Lithium/32668168560.html
I have opened a dispute, will see how it goes.

That sucks, especially if you bought a large quantity. What I learned is that you are more likely than not to get nickel plated steel.

You pretty much have to buy only from verified sources. If you can't find any the only thing you could do is try and buy only from places who have a lot of orders and reviews.

Lots of times if the prices are too cheap then it is most likely nickel plated steel. Many times the sellers don't even know what is pure and what is nickel plated steel.

One of the sellers who always sold pure nickel seemed to have closed down his store.

Does anyone hae any sources for pure nickel strips now?

 

[Allex]

Has anybody seen these holders before, the pack would be very compact with them.

Also does anybody have a good Ali-source for the big black rubber heat shrink? It is more durable than PVC alternative.

 

[Mammalian04]

Hi Alex, I like those spacers! Is that on AliExpress?

Sorry, no lead on the rubber heat shrink.

 

[Allex]

Hi,
I just found a picture, I dont know where to get them so this is why I am asking if some one has seen them on Ali or elsewhere.

 

[chucho]

Has anybody seen these holders before, the pack would be very compact with them.

Also does anybody have a good Ali-source for the big black rubber heat shrink? It is more durable than PVC alternative.

There you have :wink:
https://m.es.aliexpress.com/item/32729220653.html?trace=wwwdetail2mobilesitedetail&productId=32729220653&productSubject=18650-battery-holder-Cylindrical-cell-2-10-plastic-holder-18650-lithium-ion-battery-bracket-plastic-case&spm=2114.43010308.4.106.ExhYMz#autostay

 

[litespeed]

Hi,
I just found a picture, I dont know where to get them so this is why I am asking if some one has seen them on Ali or elsewhere.

Those look like the ones that come out of the Makita 18v packs.....I have a few but threw most away.

Tom

 

[Offroader]

There were posts in the past about cell holders that would hold them tight like that. So you could buy them I believe.

 

[Mammalian04]

Here are the holders on the English site.

http://www.aliexpress.com/item/32729220653/32729220653.html

 

[cut cat]

The thick heatshrink is also known as double wall.

Failing the heavy heat shrink, any sources for thin fibreglass for battery boxing using pvc heatshrink?

"Answered my own question"

G10 FR4 Epoxy Glass Fiberglass Sheet

 

[DVDRW]

Is this real pure nickel or not?
https://www.aliexpress.com/store/product/0-15-7mm-pure-nickel-strip-0-15mm-thickness-7mm-width/212674_1316380630.html
Very good price tomorrow

Is this good enough isolation between series group?
http://i.imgur.com/vZMSoKr.jpg

Welding my 14s12p pack:
http://i.imgur.com/1lYSFzL.jpg

Diy extension wires getting little hot if welding fast. And wires are pretty tiff. Anyone know where to get 4AWG silicone wire?
And if your 788 welder trips your mains breaker, you can fix it just using long extension cord to reduce inrush current.
I have 16A breaker and works fine with 15m extension (220V version).

Cheapest heatshrink wrap for 18650

 

[flippy]

i use a resistor inline wich i put parralel. after turning on i bypass the resisitor with a switch.

 

[DasDouble]

Can I reach 10A in the green light (0.3mm nikkel) with 2 times 0.15 on top of each other? Or will this not help?

 

[Offroader]

Is this real pure nickel or not?
https://www.aliexpress.com/store/product/0-15-7mm-pure-nickel-strip-0-15mm-thickness-7mm-width/212674_1316380630.html
Very good price tomorrow

Is this good enough isolation between series group?
http://i.imgur.com/vZMSoKr.jpg

Welding my 14s12p pack:
http://i.imgur.com/1lYSFzL.jpg

Diy extension wires getting little hot if welding fast. And wires are pretty tiff. Anyone know where to get 4AWG silicone wire?
And if your 788 welder trips your mains breaker, you can fix it just using long extension cord to reduce inrush current.
I have 16A breaker and works fine with 15m extension (220V version).

Cheapest heatshrink wrap for 18650

If the price looks too good, most likely it is fake, almost guaranteed it will be fake. Try and buy a lower quantity first. Honestly, mostly all nickel you find on aliexpress is fake and the sellers don't even know it is fake. Make sure you test anything you buy before using it.

If the cells are glued together you really do not need any extra isolation if the pack is secured. What you have there is plenty for safety. If you wear through that you really didn't secure the pack properly. Make sure you use high quality hot glue as some hot glue is really cheap and doesn't hold nearly as well as good quality glue.

The only packs I know which had failures were ones that were not hot glued.

 

[DVDRW]

Got 1Kg nickel strip 11.11 day 48$ and tested its legit
http://i.imgur.com/EhPxZ1R.png

Seller name "E-bike Lithium Battery" and selling only battery stuff added some hope.

 

[Offroader]

Got 1Kg nickel strip 11.11 day 48$ and tested its legit
http://i.imgur.com/EhPxZ1R.png

Seller name "E-bike Lithium Battery" and selling only battery stuff added some hope.

Thanks for posting, you should have bought their .2 x 7mm nickel. 1/3rd more nickel and it welds easy. Or the .15 x 12 is even better with 71% more nickel.

 

[Cowardlyduck]

Got 1Kg nickel strip 11.11 day 48$ and tested its legit
http://i.imgur.com/EhPxZ1R.png

Seller name "E-bike Lithium Battery" and selling only battery stuff added some hope.

Thanks. Just bought some also.

I bought some from Aliexpress seller KKK-store and it was fake.

Cheers

 

[Solarpower]

Do you guys get a full refund when the product is fake, or do you have to ship it back/partly refund?
I have some mixed experience with Ali regarding this, for me it has been much easier to get refund on eBay..

 

[DVDRW]

Thanks for posting, you should have bought their .2 x 7mm nickel. 1/3rd more nickel and it welds easy. Or the .15 x 12 is even better with 71% more nickel.

Im afraid my 787A+ welder cant handle over 0.15mm nickel. I can weld just double strip if want more current. Price per kg is same.
12mm wide strip is harder to weld (cannot see positive battery terminal)

 

[flippy]

.15 is virturally the limit of that welder.
.3 is impossible to weld. you can weld it when you can get the probe on the oter side for welding several .15 strips to a .3 end contact.

 

[Cowardlyduck]

Made my first 5P block of cells tonight.
This was a trial run using the JP spot welder to get a feel for doing it before I go ahead with the good quality Sanyo's and build a long and skinny 12S5P pack for my recumbent commuter.

I'm not sure on the best approach for linking the two rows of cells. Am I better with 4 zig-zag links, linking every cell with every other cell like on the negative above. 3 links, bridging to the middle of the shorter row as I did on the positive side above. Or do I really not need that many links since it's just parallel balancing and 2 links bridging the centres of the row of 3 to the centre of the row of 2 would be enough?
I would be inclined to go with the latter, but I'm a bit uneasy about spot welding above the cell casing (mainly on the positive side) even though there's another layer of nickle beneath. Do I really not need to be concerned?

The plan is once I've created 12 5P blocks like the above, to glue them length ways standing up and run copper wire between each block. For this I plan to use 2 rows of 14awg wire soldered in line with and on top of the rows of cells.

Any suggestions welcome.

Cheers

 

[flippy]

welds look good but way too much metal. the middle row is not needed.

just ensure there are unbroken links between the positive of one set and the negative of the other set and 1 strip across halfway to balance the cells.

see here:

http://i.imgur.com/XBtq4YJ.jpg

putting layer on layer of metal strip is not good. the actual contact area is very low.

 

[Cowardlyduck]

welds look good but way too much metal. the middle row is not needed.

just ensure there are unbroken links between the positive of one set and the negative of the other set and 1 strip across halfway to balance the cells.

see here:

http://i.imgur.com/XBtq4YJ.jpg

putting layer on layer of metal strip is not good. the actual contact area is very low.

Thanks for the tips.

Ok, yeah I can see how it's pointless to add all those layers now. I will go with one just in the centre to maintain balance and that's it.

Cheers

 

[Allex]

Found this neat configurator on e4bike site you can play with
http://e4bike.ru/page/battery-shape-configurator