Trash vented Cells?

Joined
Dec 20, 2018
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I have two cells that vented while harvesting. They have a hole in the bottom. I was hearing the popping noise while tearing the spotwelds. I do need to trash them, right? Stupid question i know but i don't know foor sure that there is no other way.
 
Put them in a bucket of salt water outside away from anything combustible. Then, once fully discharged (give it a week), put them in your pile of other cells to recycle.

Unless the cell was under pressure to begin with, nothing should happen when a hole has been created in the cell casing. As long as you don't try to charge or discharge the cell (other than the salt water thing) the electrolyte should stay inside the cell and there shouldn't be any ignition or thermal runaway, but better to be safe than sorry.
 
I've had several cells with very strong spot welds on them that tore a few holes when I first started harvesting.

If I get one now that doesn't come away easily i snip the nickel strip close to the welds and leave a small tab of it on the cell.

Since I'm using the 4x5 cell holders it doesn't get in the way at all.
 
Hello,

I had also a couple of e-Bike batteries where the metal of the cell was very thin, and it was tricky to rip the nickle band off without tearing a hole in to the cell.

Then I found out, if you don't pull upwards and instead pull back in a fast motion, sometimes there is a small piece of nickle left, but overall the cell has no hole.

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And if there is some nickel strip left, I just push it flat. At the end a cell looks like this:

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Such packs aka bike packs i just cut the end instead. No risk of doing a hole inside it.
 
Not much till you get close to end of charge. As it starts to try to put more power into the cell, it'll start to off gas as it's no longer under slight pressure. You should be able to smell it at that point. And, you should be able to smell it before it gets to hot, too.

However, you should be able to tell there's a leak before charging as the electrolyte is pretty fluid and should flow out fairly easily.
 
The cells I harvested were 250 Samsung 26H. In two of them I made a big hole. One has maybe a small hole and I trashed it, too.

The cells made a sound like opening a tin of Coke. But nothing leaked out. Just some kind of smell, a little like burnt electronics or chlorine. A Panasonic with a hole I had was leaking immediatly. So now I worry about a little hole where i maybe didn't hear the sound...
 
I think there is no simpler other way to find a hole in a cell than by seeing it. Maybe you could use a microscope or an x-ray unit... :p

A cell with a hole will leak when you charge or discharge it, so you only have to worry about the tester. So you never gonna put such a cell in a powerwall without noticing that it has a hole.

And ALWAYS if there is a sign that a cell could be bad, trash it. Stay on the safe side!
 
Thats for sure. I will inspect them after capacity check. Thought there would be anything else to check. Like low capacity, voltage drop etc.
 
Not sure if you mean in general, but in general you should check them for self discharge and measure the capacity. And it's also recommended either to measure the IR or sort the ancient ones out by comparing rated vs actual capacity (SoH). I personally use only the ones with 70% SoH or higher.
 
No not in general. In general I check them for the same parameters.

I did charge two wich in my opinion have small holes but they charged quite normal. I will upload pictures later. One did leak. The other one didn't.

Pictures will come.


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As you can see quite normal capacity. They fully charged. And they keep their charge for some days now. Very hard to figure out. In real you do not see the holes this good.
 
Ooh, that's not what I expected...

I thought they will leak more by charging. In the pictures, it looks for me like both have a small hole.

Are these LG MG1?
 
Yes i was wondering, too. Yes i think both have holes. No they are 26H Samsungs. Thats why I am a little afraid. Doublechecked every cell. But sometimes it is quite impossible to say.

Maybe I am in need for an x-ray unit :)


As said before I had a Panasonic Cell, leaking massive when it had a hole.
 
Maniac_Powerwall said:
No not in general. In general I check them for the same parameters.

I did charge two wich in my opinion have small holes but they charged quite normal. I will upload pictures later. One did leak. The other one didn't.

As you can see quite normal capacity. They fully charged. And they keep their charge for some days now. Very hard to figure out. In real you do not see the holes this good.

Taking a really close look at the bottom of the cells it looks like they have caps on the Neg side.
I have seen that!Where the cells have had caps on them for whatever reason and the nickel strips when removed leave holes but do not damage the original end cap.
Take the bottom part of thewrap off and see if the cellhas a supplementary cap on it.

image_mcjnbq.jpg


Wolf
 
No they dont have to leak on first try on charge but they are still trash. a hole = exposed for air and wont work properly even sealed..
 
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