The battery builders club

[rusins]

Saw a review on their site in german that I think translated to “failed to weld 0.2mm nickel”, but I’ll take your word for it.

[Prism]

Anyone know of a good place to source silicon coated stranded copper wire in the EU?

I’d say turnigy silicone wire form HobbyKing. That’s what I use.

[Acido]

Kweld is basically just a switch, a power source can make it great or shit, same as the boss level/any other welder

[EboardSolutions]

yes pure nickel

[deucesdown]

Welcome!

• ( Answered ) I haven’t bought a spot welder yet. I want something compact so that I can take it with me when traveling. kWeld VS Boss level welder sold by aluakiria. Seems like the boss welder is way more powerful, but the kWeld is available as a kit with everything. Also have heard reports of people’s boss welders breaking / some functionality not working after a while.

kWeld is definitely the more robust and capable welder. Hard to kill and very powerful. Boss is smaller (1/3 size) and more multifunction (soldering iron). There’s a mini boss if you’re looking for portable.

• I’ve read that nickel strips can’t carry much current. I plan on building my packs with PCBs for each parallel group (cause all the cool kids are doing it), so I only need nickel to connect the cells to the PCB. However, for something like a 40T cell that can do 30A, that’s a whole lot of nickel! Do people weld nickel onto nickel for powerful packs like that, or move on to copper, or what?

Copper is better but not really practical to spotweld, and copper film of the thickness we can attempt to weld is physically flimsy. 0.2mm nickel seems like the practical limit for the normal spotwelding process. Going further requires some changes to the process. Get the widest strip you can fit. If I were you I’d look at 25mm or so wide, folded over onto the pcb.

• What do you use to cut the nickel strips? Would sheet metal scissors work?

scissors work, at least for a little while. I use tin snips, but they leave kind of a serrated edge.

• What do you use to flatten the nickel after doing a cut? One of those metal clamps that screw on to tables?

I go around with smooth jaw flat pliers. Like these

Amazon.com: Flat Nose Pliers 5 Inch Smooth Jaw Pliers for Jewelry Making, Wire...

• When to use fishpaper, when to use kapton tape?

Fishpaper for abrasion resistance, kapton for heat resistance but not abrasion, and when you need it to be thin.

• If I only use non-corrosive materials, why do I have to worry about water getting into my pack? (As long as my BMS has conformal coating and the whole enclosure isn’t flooded lol)

Yes you should worry. Unless you’ve potted every single piece of electronics.

But you could design your stuff to not let electrical components get wet if a bit of water gets into your enclosure (because sooner or later water will get in).

• ( Answered ) Anyone know of a good place to source silicon coated stranded copper wire in the EU? My hardware stores suck and electronics stores fine a premium. Same question about where to purchase fuses for the charging port.

ebay and aliexpress for silicone wire. Look for “tinned copper”, “flexible”, “many fine strands” (look at specific strand counts, compare listings. there’s a standard high strand count for each awg). Other than that the wires are pretty damn similar across sellers. It’s always a pain to search for the well priced ones.

Fuses look at digikey, mouser, arrow. Don’t buy generic fuses.

Charge port, there are so many choices…

[rusins]

Thank you for answering so many of my questions! Will look into getting wide nickel strips for 21700’s lol

[Flasher]

I have a welder question. What cheap but functional welder would be suggested to me? My criterias are simple.

1)Must not work on lipo.
2)Needs to work out of the box (least building possible)
3)Must not work on lipo
4)No need to be portable
5)Must not work on lipo
6)No car batteries
And most importantly,
7) MUST NOT WORK ON LIPO
any suggestion?
Ps: I use Canadian rupees (worth shit)

[ZachTetra]

A car battery with nails and jumper cables

[Flasher]

Defies number 2)no tinkering

[ZachTetra]

Whatcha mean? There are no settings to play with

[ZachTetra]

It either makes a pack or burns down your house, no inbetweens

[Flasher]

@ZachTetra just for you

6)no car batteries

[Prism]

Well, the only thing that I can think of that fits are the sunkko spot welders.
But I don’t have any experience with them. I just know they are out there.

[legend27]

You must need some kind of power source.

How about you take some copper nails and bend them at an angle. Then put them in your outlet and then you’re ready to weld! Just turn the outlet on/off really quick like reaaaallly quick.

Remember to not touch both nails at the same time when you are welding!

Good luck!

Edit: you could also make one of those welders with a microwave transformer. Needs a lot of building though…

[stratoglide]

It’s possible to build a spot welder from a microwave transformer but honestly spot welders kinda suck on 120v. To get reliable welds I’d say a Lipo or battery spot welder are a must.

Or you’re using industrial grade equipment on high voltage lines.

Tl:Dr buy a boss and a lipo it’s worth every penny!

[BCoad]

I have a cheap sunko spotwelder it worked right out of the box and so far has had 0 issues. But I’ve only made one 10s 4p with it so don’t know the longevity. I’m on 240volt power think I remember something about them not being as good on 110 volts. which do you have in canada?

[Flasher]

Guess this just means I won’t be welding anytime soon.
I dont want lipos inside my house. Too many bad stories have made that clear in my head

[Flasher]

I have access to both. It’s just a breaker switcheroo (I made the electrician wire everything for 220/240v but breakers are set for 110)

[BCoad]

Well sunko works 4 me so far on 240 i had to put in some effort to rip of the test welds with pliers . I think it was Aus$160 on ebay so probably about us$90
edit us$110 just converted it

[Flasher]

Which comes to 145$cdn