Strange looking VTC5A

[Winblows]

Hi,
This battery is about 1 year old and is one of many. I use decent chargers (Nitecore, Efest).
Is it a sign of leakage?

 

[untar]

This question keeps surfacing every 2 weeks or so. I don't think there is a single answer to why it looks like this, there are several hypothesis (eg micro punctures or oxidation on the can, body fat from hands etc) but every time I have rewrapped such a battery I couldn't for the life of me figure out what it was, the wrap looked fine (tested for punctures in the dark against a light) and there was no liquid or visible oxidation on the can.

Probably still best to just rewrap it to make sure there's nothing until we know all the reasons why it happens and how to tell which one it is.

 

[Rossum]

To me, that looks like a bit of e-liquid wicked its way between the body of the cell and the wrap.

 

[Winblows]

... never had a flooding disaster ...
yes, a leaking tank, but I never recognised any liquid inside the 510 connector hole.

 

[suprtrkr]

I'll go with @Rossum That's a drop of juice that got inside the wrap. Doesn't have to be a leak on the mod. You might have had it on your finger when you changed batteries.I doubt it's a problem, but wraps are cheap. Do yourself a favor...

 

[Baditude]

This question keeps surfacing every 2 weeks or so. I don't think there is a single answer to why it looks like this, there are several hypothesis (eg micro punctures or oxidation on the can, body fat from hands etc)...

I agree with this. This phenomenon seems to be isolated to just Sony batteries, and has been reported sporadically for at least 2 - 3 years. Nobody seems to really know why it occurs, or if it is something to be concerned about. I believe Mooch was able to reproduce the phenomenon by putting pin holes in the insulation wrap, but even he is not certain why it occurs. Since it seems isolated to just Sony batteries, perhaps it happens because of the particular insulating wrap used or maybe an adhesive used by Sony to secure the wrap...but that is just circumstantial guesswork on my part.

I'm going to disagree that you need to rewrap the cells, but that is certainly your perogative. As long as the current wrap appears intact without holes or tears, the battery is safe to use "as is".

 

[stols001]

Uh, I've had sort of that (not to that extreme though, lighter dots) in a Samsung battery and I'm going to GUESS AT SOMETHING.

We all know batteries get warm (not obviously) hot while vaping and charging sometimes, I wonder if it is some slightly uneven heat pattern getting imprinted on the battery (maybe with the smallest amount of juice, yes, sort of snuggling it's way up under the wrap.

Total, 100% guess, but I just rewrapped mine, and I wonder if it may have something to do also with how snug and what material is containing the battery (plastic, vs. metal) vs etc.

IDK it's a thought.

Just rewrap it though, in my experience nothing is visible on the battery, only the wrap, and well, wraps are cheap. Etc.

Anna

 

[zoiDman]

... Since it seems isolated to just Sony batteries, perhaps it happens because of the particular insulating wrap or maybe an adhesive used by Sony...but that is just circumstantial guesswork on my part.
...

That is what I assumed was going on. That is it was the Wrap and Not the Cell that was the cause.

What would be Interesting is to know if this Discolouration occurs in Other Applications besides e-Cigarettes? Like in Flashlights or say Power Packs?

If it does, then some type of Chemical Reaction with e-Liquids might be Ruled Out.

 

[Winblows]

Rewraped
Thanks all!

 

[Baditude]

That is what I assumed was going on. That is it was the Wrap and Not the Cell that was the cause.

What would be Interesting is to know if this Discolouration occurs in Other Applications besides e-Cigarettes? Like in Flashlights or say Power Packs?

If it does, then some type of Chemical Reaction with e-Liquids might be Ruled Out.

I agree that it seems it is the wrap that gets the spots, not the metal can under the wrap. That is why I said that perhaps it is the plastic wrap used, or an adhesive, used by the Sony/Murata factory.

Just a curious observation. Sony moved its battery manufacturing plants to the Phillipines after floods destroyed its Japanese plants after the earthquake and tsunumi flood. To the best of my knowledge, the Sony/Murata batteries are the only batteries that come from the Phillipines. May be totally inconsequential, but may also be a clue.

(Sony recently sold its manufacturing rights to Murata, so Sony no longer has anything to do with 18650 batteries.)

 

[puffon]

My guess...
It's some kind of "lube" used to facilitate easier machine wrapping.
I've had it show up on AW batteries.

 

[Rossum]

Rewraped
Thanks all!

I use clear, transparent wraps as over-wraps to protect the stock wrap on cells that I use in mods that will accommodate the extra diameter.

But I don't think it's wise to use them as the only wrap on a bare cell because it's difficult to see small tears, holes, or other flaws in them.

 

[zoiDman]

I agree that it seems it is the wrap that gets the spots, not the metal can under the wrap. That is why I said that perhaps it is the plastic wrap used, or an adhesive, used by the Sony/Murata factory.

Just a curious observation. Sony moved its battery manufacturing plants to the Phillipines after floods destroyed its Japanese plants after the earthquake and tsunumi flood. To the best of my knowledge, the Sony/Murata batteries are the only batteries that come from the Phillipines. May be totally inconsequential, but may also be a clue.

Yeah... It might be that there is an Impurity on the Cell Casing that is Reacting with the Wrap? Like Forming Lube that was used when the Casing was drawn? Or something from the Production Line?

Or Maybe the Wrap Reacts with Oils from the Skin? Or something then Wrap is in contact with in a Mod? Like Polystyrene?

Or maybe the Wrap is undergoing some type of Redox due to Heat and Condensation?

Dunno?

I Hope No One ever figures it out. Because in the Immortal words of Richard Feynman, "Life is so much more interesting when there are a few mysteries that we might not ever know."

 

[untar]

it is the wrap that gets the spots

The thing is when you remove the wrap the "stain" disappears completely. Nothing on the wrap, nothing on the cell, no trace of it whatsoever (talking about the version from the OP, "creep from bottom to top stain", the one in your post looks a bit more concerning and I never had that one).

 

[Rossum]

I agree with this. This phenomenon seems to be isolated to just Sony batteries, and has been reported sporadically for at least 2 - 3 years.

Is it possible that it only shows on Sony cells because they use a translucent wrap, whereas other cells use an opaque wrap, where one would never notice if a bit of e-liquid had wicked in under the wrap?

 

[Baditude]

Is it possible that it only shows on Sony cells because they use a translucent wrap, whereas other cells use an opaque wrap, where one would never notice if a bit of e-liquid had wicked in under the wrap?

It's possible for sure. I wasn't aware that the Sony cells use a translucent wrap because of the green color. I haven't used a Sony cell in a few years.

 

[zoiDman]

Is it possible that it only shows on Sony cells because they use a translucent wrap, whereas other cells use an opaque wrap, where one would never notice if a bit of e-liquid had wicked in under the wrap?

That could be True Also.

Because in the OP's Photo, it sure as heck looks like some Liquid has seeped its was under the Wrap from the Negative End.

Someone Needs to take one for Science and put a Bunch of Different Batteries with Different Wraps into a shallow tray of Water/Oil/e-Liquid and see if they can replicative what Winblows is seeing.

 

[Rossum]

It's possible for sure. I wasn't aware that the Sony cells use a translucent wrap because of the green color. I haven't used a Sony cell in a few years.

Yes, you can see the inkjet printing on the metal body of the cell itself though the wrap. I don't recall any other cells that have the printing on the body of the cell rather than on the wrap.

Someone Needs to take one for Science and put a Bunch of Different Batteries with Different Wraps into a shallow tray of Water/Oil/e-Liquid and see if they can replicative what Winblows is seeing.

A bit of e-liquid would be ideal.

 

[Baditude]

Yes, you can see the inkjet printing on the metal body of the cell itself though the wrap. I don't recall any other cells that have the printing on the body of the cell rather than on the wrap.

Interesting observation. Makes a lot of sense.

 

[Winblows]

I use clear, transparent wraps as over-wraps to protect the stock wrap on cells that I use in mods that will accommodate the extra diameter.

But I don't think it's wise to use them as the only wrap on a bare cell because it's difficult to see small tears, holes, or other flaws in them.

I have 2 VTC5's that I re-wrapped and they don't fit in all of my mods anymore.
So... I don't think it's a good idea (transparent wraps as over-wraps) for me