PSA: Do not weld on the outer ring of LISHEN cells, or any cell with a bottom vent

Cautionary tale: I found a small puddle under battery after charging it

Summary: He welded these normally and they started leaking electrolyte

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Outer ring?
It was the sort-of-centered vent ring on the bottom of the cell he was welding on. We might still be able to spot weld on the outer ring of normal flat metal on the bottom. But we just don’t really know yet.

But even if we avoid the ring we are still blocking the bottom vent with the nickel strip and that cannot be a good thing.

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Not all Lishen cells are bottom vent either.

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Thank you for the correction!

What should we do to reduce the chances of this happening?

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Don’t weld on or near the ring. :slightly_smiling_face:
I’m still worried about the bottom vent being blocked by nickel strip even if the welds avoid the vent ring.

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Do all cells have this? First I’ve seen of it

I understand the LR2170SD has this ring and we shouldn’t weld on it, but what about other Lishen Cells? LR2170LA maybe?

Some BAK cells also have bottom vents.
Linking this.

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Already replied to you in the other thread

I know, I just wanted a 2nd confirmation plus it’s good to keep the data consolidated. with this being on a cell-cell basis and the title stating it applies to ALL Lishen cells I’d like to remove any confusion.

Right, it is too general. Not all Lishen cells are bottom vent

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What should I change the title to?

I would suggest replacing “LISHEN” with “any cells that have a bottom vent”

it’s on an individual cell basis from multiple manufacturers/resellers

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The Lishen SD and SF have bottom vents.
The Lishen SA and LA do not have bottom vents.

If desired, this can be confirmed with a search or by checking out my test reports.

There are some other 21700’s (VTC6A, IIRC) and 18650’s with bottom vents too but I don’t have a list handy.

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Mmm something like " PSA: Do not weld on the negative ring of bottom vent cells"

Would be less specific

Lol this is how I knew this, also you can tell its not bottom vent by looking at the cell

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“Do not weld on/near the bottom venting ring of any cell”?

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For additional background info, here’s a great 6 minute video on bottom vents: Battery Safety: How does a bottom vent help against exploding batteries? (18650, 21700, vent) - YouTube

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this is some great clarification.

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I like the idea of having lishen in the title because it’s the most popular vented cell in diy esk8 currently

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though, only 2 of the 4 models they cell actually have the bottom vent.

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