Is this cell "dunzo?"

Today, upon periodic inspection of a light that doesn’t see regular usage, I discovered the condition below.

The dark deposits are hard, and perhaps crusty.
The lighter deposits that look like grease can be smeared a bit, like a thick grease. However, it isn’t excess lube from the threads or anything of that nature.
The spring cleaned up fine with some contact cleaner, and wasn’t corroded like one would see with alkalines.

Can’t say when the cell was manufactured, but the light it was bundled with was obtained ten months ago in October 2019.

I’ve never experienced a leaking Li cell before, so I’m trying to get a better understanding of the situation. But, my overall experience suggests that unexpected secretions are not good things, for either people or batteries.

I would probably toss safely recycle it. Especially given that a new 18650 of reputable quality is $5 to $10. It’s a lot of risk over $10.

If you really want to try to salvage it, I’d say to test it first and observe it the whole time. So, measure voltage now, then capacity and internal resistance, and make judgements based on that.

If you show it to Sofirn, please come back and tell us their response.

I’ve had a couple of cells develop that brown leakage, in storage, but only after several years.

It looks like Flux? Maybe the button top is soldered on and when you stand the light bezel down it leaked out?

Uhhh, yeah, any Li cell that starts oozing anything gets trashed.

Or find some nice Ukranian fellas who’d drive a nail through it to watch the sparks or something.

“But, my overall experience suggests that unexpected secretions are not good things, for either people or batteries.”

Too true, too true.

Sounds like something Big Clive would deadpan. :laughing:

I might ask them about it, but I’m not sweating it, since it was a cheap light, and I have other cells to replace it.

The light does rest head down, but I doubt the black substance is flux.

I do have a slight desire to see some fireworks. I’ve had to find a creative way to dispose of a volatile substance (old gasoline) before…

Depends on what kind or type of Flux (corrosive) was used and the reaction to the soldered metal/material….

Gotcha. I’ve never come across creeping flux, so it’s new to me.