200A discharge 3.7V 8AH flat pouch lithium ion cells

They still have them for $4 a pop on BatteryHookUp

I know, but try to order them to Europe ā€¦

@linsus let me know your price, and i will think about it.

11 cells in that pack lol
i can count


Red is where you would need wire or some busbars
Highlight is where tabs need to be isolated. lol missed some spots

thinking about itā€¦ I donā€™t seen how that layout is any better than this:

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I am tempted to go buy a ton of similar shaped candy bars to mess around with layouts.

oh wait I can just use the actual cells. lol

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Iā€™m pretty sure these are aluminum on the positive side, and tin plated copper on the negative. If you look closely at the edge of the negative side, you should see copper color. Iā€™ll check under a scope to verify, but thatā€™s what Iā€™m remembering.

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Setup time is likely to be the main cost of having something like this laser cut, cut time is gonna be highly dependent on the machine itself, and the shop doing it.

Personally, Iā€™d shear to length, from bar stock the width and thickness you want. May not sound like it, but even one person operating a manual shear with proper setup this is a very quick job. Especially if you can run it batched.

Otherwise, I can saw them to length very quickly on my horizontal. Trick is just to have a stack of bar and saw them all at once, tack one end together, setup a stop if you donā€™t have a feeder, cut as many tall as you can fit in the vise.

I used to work at this shop, so Iā€™m aware :slight_smile: but running the shear on something that needs holes drilled out as a second operation would be much more expensive in lieu of just running the job in the laser as one operation.

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Oh sorry I must have glommed over you guys wanting holes in it. Were you planning to laser the bores, with no second op?

Obviously thereā€™s a million ways to skin any cat, pretty easy to do all this with an ironworker or any punch press very quickly also depending on whatā€™s available, with aluminum this thick, drilling/boring would be pretty wasteful of time and tooling when they can be punched so easily. I just like to remind people that using a large process format like laser, plasma, waterjet, etc, isnā€™t always the most economical route. Whatā€™s that saying about everything looking like a nail when youā€™ve got a hammer or whatever the cliche is? :laughing: Anyway, apologies for the unsolicited advice.

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No need to apologize for giving advice :smiley:

The processing time between pulling a sheet of aluminum, loading it on the table and setting the program to run for a laser (Bystronic BySprint 4k Fiber 4020) is accounted for in the pricing for the laser operation time in the first place - mostly because the handling cost of the material is either - 1 baked into the price of the stock in the first place, or 2 baked into the price of the fabrication operation. But again this is how it happens at the shop that im referring to - I know this because I used to work there, and trained all of the guys in the fab department that are there currently.

A super old picture in front of the CO2 ByStar:

The laser can easily cut the holes (since these would be bus-bars they would need holes in them at some point), and from a commercial/group product Iā€™d rather opt for it to be done at the same time as the cutting operation rather than sending ā€˜blanksā€™ that need to be drilled out. That said, I donā€™t know about the options of using a punch on aluminum and its largely irrelevant since this shop doesnā€™t have one :smiley:

The point of using this shop rather than some other place is that since they know me, chances are I can still get a good price through one of my old supervisors or a few of the guys I know in the sales department.

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Cool, long as the cost work out to where everyone is happy, and the logistics are easy, itā€™s always a win!

If for some reason it doesnā€™t play out, and you need some help let me know. Iā€™ve got full run of a large tool and die outfit with multiple very large high resolution fiber lasers, large capacity plasma, wire EDMs, etc. and full manual machine shop at home (shop is my home lol).

In the hypothetical event you end up needing to make many many thousands of these or similar in the future, even without full on stamp pressing dies for sheet, they could be cut to length, and punched in one op from bar, in multiples, with a very easy setup, with edge quality being determined by the base stock basically and perfect kerf free holes and zero HAZ. Even if they were steel, but especially aluminum. Sometimes the old ways, still offer advantages. Just some info for the mental toolbox. Cheers!

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They are made on my friends CNC, out of 4mm 1050 alu. So not very much for me personly !

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what are the full dimensions? if you donā€™t mind. I cant get a quote from the fab shop until I know what dimensions would be needed.

Yo guys my friend and I are working on a project with the 144 pack of these. Itā€™s going to be a 16S9P battery, any suggestions on BMS for them? Iā€™ve heard you can get a ton of charging amps into these guys, so I was wondering what suggestions might come up.

https://www.lithiumbatterypcb.com/product/20s-84v-lithium-bluetooth-bms-with-100a-constant-discharge-current/

Thatā€™s the one I was looking at, I wanted to have a smart BMS. I donā€™t know if itā€™s worth buying one with the discharge capability or if we should just go with a bypass. Let me know what you guys think

I use one of these bluetooth BMS for my 20s battery. Bypassed for dischargedā€¦ Love the features

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anybody have 13 of these they want to get rid of perchance?
Looks like the website is out of them

Also, does anyone know the weight of these?

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I guess I would try to sell some if you need. weight is like 300? 600g?

Wait really? I had just looked and it said that they were still there

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yeah guess battery hookup is out, doubt BCH is yet.

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Oh yeah I got my pack from BCH, they were cheaper anyway

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I got 285 grams here. Ā± a few tenths of a gram.
I gotta build a 3s3p here in a minute, puzzling over how to make these connections
@Arzamenable

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