The battery builders club

[ZachTetra]

Is this from the pack you tried to sell a while back?

[Halbj613]

yep took it apart into p groups but dont need anymore
paid prob 350 for the cells and nickel so not looking for much for it

[Halbj613]

anything particularly bad you can see? i can see one joint which didnt stick to well which im gonna do again.

[abusfullofnuns]

Here’s where I landed. Not at all happy with the enclosure depth but hopefully won’t look too terrible.

[oldman]

I think your soldering is not wet enough or hot enough.

[ZachTetra]

Needs more solder and more heat

[Halbj613]

cheers will do

im assuming i can still add on now?
maybe could you send a close up of what it should look like?

[ZachTetra]

[Halbj613]

cheers thanks will get them to look more like that.

[Darkie02]

That almost looks cold you didn’t heat/tin the nickel enouth shouldn’t be balling up we’re it connects to the nickle

See how it flows in to the nickle not mataining surface tension

[ZachTetra]

I tin both sides, then I just added more material on top (it all flowed so a solid connection). It’s easier to get it pretty with smaller wires though

[JoeyZ5]

That hole punch technique looking fineeee

[Darkie02]

[ZachTetra]

You are a genius for that one

[BenjaminF]

@Halbj613

@oldman

not wet enough or hot enough.

What he said.

@Halbj613

maybe could you send a close up of what it should look like?

[Serious] How To Solder-The Complete Tutorial From A>Z

Here is a tutorial on how to solder. We will discuss everything from how-tos, what tools and tips & tricks. - Here is a list of what you need. Tools | What you actually need"] First off, a soldering iron, not a pistol. Basically a long stick with a metal rod. Solder. It needs to be 60/40 that has a rosin core. People use 63/37, it is personal. Flux Helping Hand/soldering Jig Brass coil/or just use a damp cloth that you don’t need. Desoldering Braid - Sooooo many soldering irons! Which one? …

@Halbj613, re-read this

[Halbj613]

looking a bit better?

[YeetMeat]

Maybe it’s just me but those look like they might be missing a bit of solder.

Also remember to tape up the p-groups you aren’t actively working on so nothing accidentally shorts.

This thread might also give you good ideas of what to aim for your pack to be like

[Halbj613]

i put a ton of solder on them and it just kept building up on top
the connection is very wet and really tightly bonded

[Sharky]

May i ask you regarding a battery i wanna build if this would be ok:
So i wanna make a 16s 4p battery with 27100 cells tht have a discharge current of 45a
When i spot weld the seriel connections with 0.2x20mm nicel strips do you think this would be ok or do i need to add additional copper wires between them?
Thx for your input

[rusins]

1. Molicel P42a can only do that much current if you monitor their temperature. 25A, or maybe 30A is probably the max you should be running them at per cell.
2. When choosing Nickel, I like to go buy this chart of data gathered experimentally with nickel welded to cells made by some guy on the e-bike forum.
   
   

So if you’re building a 4P battery, and expect 25A per cell max when drawing power continuously, you need the series connection to be good for 100A. From this chart we can estimate that 0.2mm x 20mm nickel should be good for about 36A max. So if your series connections are just pure nickel strip, then you should stack 3-4 layers of it.

This is why for high current packs usually people connect the series connections with regular wires or copper braid, and not just nickel.