Rattle in a cell

S

Stefaan De Ridder

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Joined
Jun 25, 2017
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some of the cell's I'm testing rattle a bit when shaken.

the sound of something loose inside (in the head)

but they seem to have good voltage, get charged, and remain at an acceptable voltage level.

how come?

if they had vented in the past, surely the protective device would be popped, and then it would read 0V, or am I mistaken?

mainly Samsung ICR-18650-22P

question is, are they still safe? does anybode have the same problem? or can you shake some Samsung and maybe you hear the same, and never noticed.

best regards

Stefaan
 
I wouldn't use them. Sounds like a piece of the protection circuit has broken somehow. It's on the + end under the cap.
 
they are not fake, coming from e-bike battery packs (can't image they put in fake cells.)

and I can't see anything moving on the plus side.

but if a cell has vented (maybe a little) the protective device would still be open, and thus reading 0V, or not?

or is the protection 'self-resetting'

best regards

Stefaan


image_shqaxp.jpg

image_dpsgyy.jpg
found a diagram of the protections, I can not find anything that could rattle if the cell is good.

still testing cell, not yet building my packs, so maybe I'll retest this 'rattlers' a bit more.

best regards

Stefaan
 
Generally the CID does not reset and it does not rattle when failed. Sounds weird. I would not use em. I would take em apart to fint whats rattling
 
I've never encountered any rattling in the 3000+ cells I've handled. If you don't wanna cut one open, I'm willing if you wanna send 1 to me
 
me too, never had a rattling cell, also tested 3000+... I'm very curious what's the cause, please open, examine and share :)
 
I'm curious too, but how do you open a cell in a safe way?

I'm thinking that maybe the spacer (the blue thing in the photo) is loose.

and depending on location, I can send one to others, I've got a few.

only thing is, this weekend I'm not where the batteries are, It will have to wait until monday.

best regards

Stefaan
 
StefaanDeRidder said:
I'm curious too, but how do you open a cell in a safe way?

I'm thinking that maybe the spacer (the blue thing in the photo) is loose.

and depending on location, I can send one to others, I've got a few.

only thing is, this weekend I'm not where the batteries are, It will have to wait until monday.

best regards

Stefaan
Click to expand...

if you like, you can send one to me in Germany, I'll open it carefully in a bunker :D . Just PM me for address...
 
I'm in NYC, drain the battery to a few millivolts and Dremel it open
 
Can be opened with pipe cutter too.
 
Today I will be sending 2 cell to Owitte (Germany being the closest to Belgium), so will be watching his investigation.

I'l try to cut one open myself, but do not have a dremel.

First I will try to X-ray one, maybe I can see the inner parts. Will keep all of you posted.

Best regards.

Stefaan
 
StefaanDeRidder said:
Today I will be sending 2 cell to Owitte (Germany being the closest to Belgium), so will be watching his investigation.

I'l try to cut one open myself, but do not have a dremel.

First I will try to X-ray one, maybe I can see the inner parts. Will keep all of you posted.

Best regards.

Stefaan
Click to expand...

You don't have a dremel, but an x-ray device at home...? Nice :D

I'm waiting for your cell and will document the 'opening ceremony'. Does anyone has an idea how to do it without completely destroying it? I don't really want to use a dremel (although I have one) and cut it open, maybe there's a more gentle way to do it...

Have sun!
Oliver
 
x-ray at work, not in my house :D

don't think the governement would like me to have that at home

but to find the reason of the rattle, it will need a gentle dismantling.

best regards

Stefaan
 
As said, X-rayed one of the rattlers.

problem of course is you can not see plastic on industrial X-ray, or I have to lower the X-ray voltage and wouldn't be able to see through the metal casing. :s

I was expecting to see something similar to the schematic I posted before, with a CID or something, at least some sort of dent in the positive plate.

do those samsungs have some sort of protection? I'm confused.

best regards

Stefaan
image_ectpik.jpg
 
Looks like it's time to cut it open
 
I've send 2 cells to Oliver, waiting for his finding.

Tomorrow I will retry the x-ray, try to get a better view.

Problem is taking a picture of the actual x-ray on a high density viewer, loosing a lot of detail, and too much backlight

@Oliver: please let me know if/when the cells have arrived, and watch out, they are charged.

best regards

Stefaan
 
ok, you can x-ray at work... was about getting envious, because I don't have one ;).But as speaking of this: I have some dentists as customers, maybe I can ask one of them to x-ray the cells with less power in order to ha ve a look inside before I open them.

Will get back here as soon as I have some news :) .

Have sun!
Oliver
 
OK, cells arrived on saturday. Here're the results of my first inspection:

+ Cells behave as normal, I tested them both successfully, the OPUS found around 2100 mAh
+ The rattling sound doesn't seem to come from the top. I located the sound at the bottom of the cells. If you shake them and put your finger on the bottom, the sound changes, gets a little dull.

I just made an appointment with one of my clients to x-ray the cells again. If I can't find out more this way, I'l completely discharge the cells and open them. Stay tuned... :)
 
X-Ray for the win.... well done..lol
 
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