Battery kit - Does it need spot welding?

Batteries, Chargers, and Battery Management Systems.
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cwah   10 GW

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Battery kit - Does it need spot welding?

Post by cwah » Sep 18 2019 5:38pm

Hello,

I'm not clear about this product:
https://www.aliexpress.com/item/32838272069.html

It looks like a kit I could assemble just with some screws. But the description says welding. I'm not sure if it's the english that is wrong, or if it needs to do spot welding on top of that?

From what I see it looks like it doesn't need to?

Thanks
Help me find my stolen electric brompton: http://bit.ly/1a0vbBC and Bosch Sinus B3 http://bit.ly/1eV0WQz

Shunt   100 mW

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Re: Battery kit - Does it need spot welding?

Post by Shunt » Sep 18 2019 6:12pm

It does require spot welding. Those are just holders and not modules with contacts.

cwah   10 GW

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Re: Battery kit - Does it need spot welding?

Post by cwah » Sep 18 2019 6:16pm

Shunt wrote:
Sep 18 2019 6:12pm
It does require spot welding. Those are just holders and not modules with contacts.
If you look at the nick strip, you can see little groove which would force contact with the cell:
Image
Image

So does it really requires spot welding? The pressure from the screw and the little groove will guarantee contact
Help me find my stolen electric brompton: http://bit.ly/1a0vbBC and Bosch Sinus B3 http://bit.ly/1eV0WQz

Shunt   100 mW

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Re: Battery kit - Does it need spot welding?

Post by Shunt » Sep 18 2019 6:23pm

"3. Battery holder can be spliced by locking bar. Holder and locking bar is separate design. Then it is ok to weld small battery pack firstly, and then to assemble big battery pack. (Another factory holder only can be assembled firstly, and then to weld battery pack. It is not good for big battery pack assemble) "

It's intended to keep the cells secure , but they still have to be welded.

Shunt   100 mW

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Re: Battery kit - Does it need spot welding?

Post by Shunt » Sep 18 2019 6:29pm

Even those Vruzend caps that have spring loaded contacts have to be secured with bolts basically to maintain enough pressure . Physics just isn't kind to pressure contact methods of battery building. Probably the best solution that doesn't involve welding is AmTech https://18650.lt

john61ct   100 MW

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Re: Battery kit - Does it need spot welding?

Post by john61ct » Sep 18 2019 10:18pm

The plastic parts just hold the cells in place laterally.

The copper thread is to provide contact from wires with crimped ring-terminals to that section of spot-welded conducting nickel plate.

The locking tabs let smaller blocks be physically connected into big packs.

Looks pretty well thought out to me, but the layout, wiring specs etc would require a bit of design know-how.

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