123 cell protection anatomy revealed

[picard]

Originally Posted by carrot

So these batteries are just rolls of... electrodes? I don't quite remember chemistry class.

I'm surprised... I thought there were pixies inside.

yeah, I really thought there were a dozen pixxies working hard pedaling stationary bicycles to generate power.

[NewBie]

Okay, instead of the Energizer/Surefire cell shown above, some have said the Duracell was identical. Well, it isn't.

It has a few of the same basics and that is where things depart:

[SilverFox]

Hello Newbie,

I can't seem to make out the vent spike that Duracell refers to on their exploded view. Is it there?

A question comes to mind... Are hundreds of contact points in a friction fit better than a single welded point?

Tom

[Size15's]

Excellent thread! Thank you for making CPF great!

[chimo]

Newbie, thanks for another great disection.

Originally Posted by SilverFox

A question comes to mind... Are hundreds of contact points in a friction fit better than a single welded point?
Tom

One benefit of this implementation if that the current should be more evenly distributed across the grid structure. It is also possible that this provides a better heat transfer to the top cap for thermal activation of the PTC.

Paul

[NewBie]

Originally Posted by SilverFox

Hello Newbie,

I can't seem to make out the vent spike that Duracell refers to on their exploded view. Is it there?

A question comes to mind... Are hundreds of contact points in a friction fit better than a single welded point?

Tom

I see no vent spike.


There is a "springyness" to the hundreds of individual contact points, which would be alot like having the tailcap battery spring in many flashlights, but hundreds of redunant ones.


I did notice the PTC in the Duracell battery showed no blemishes from being "overly" crimped like I saw in the SureFire/Energizer cells.

[NewBie]

Though I do recall reading that the typical vent is designed to rupture at 40 PSI.

[NewBie]

Due to some recent events of exploding 123 cells, I took some more pictures for another thread, but I'm going to also put them here, so everything is also in one concise thread.

Mod/Admin, if it is an issue, please holler.

-------------


Well, decided to take some more pictures for folks of the button top and it's construction on the SureFire/Energizer and Duracell batteries:








I also ran another test, with a Duracell 123 that I cut open, and dropped in some water, at times it made more bubbles than you see in the picture, but that is about all that happened. It may be due to the limited rate at which the liquid water can actually enter into the tightly wrapped cell, which would be much different than a moisture filled cell that heats up...



Please folks, do NOT EVER try any of the stuff I am showing you, I've seen some of these cells violently throw flames and hot molten material like a rocket engine. I have some special 1/2" thick plexiglass that I do all this stuff behind, forced ventilation in an open area, and thick welders gloves, and I still wear a full face chemical shield and sealed goggles, and a few other safety precautions.

[cy]

very interesting info...

[chimo]

More great pics! Is that a solder blob on the button?

Paul

[NewBie]

Originally Posted by chimo

More great pics! Is that a solder blob on the button?

Paul

It sure is. I used it for making a very solid connection for some high current testing I was doing. I'd not recommend anyone else doing this, it can be very dangerous to say the least, causing a short in the cell, and a resulting vent/explosion.

[InfidelCastro]

Makes you wonder how the protection failed to initiate in the Battery Station cells in that last Ka-Boom thread.

[NewBie]

Originally Posted by chimo

More great pics! Is that a solder blob on the button?

Paul

It sure is. I used it for making a very solid connection for some high current testing I was doing. I'd not recommend anyone else doing this, it can be very dangerous to say the least, causing a short in the cell, and a resulting vent/explosion.

[NewBie]

Okay, here is the internal construction of the Battery Station 123 cell, shipped to me on June 26th, 2006, manufacture dated as 02/06, and is brand spanking new, I've had it less than 2 days:

Overall cell:



Taking the wrapping off:



The top of the cell, with the black washer off:



Intact cell internals, can opened:



Seal end of cell, showing how the seal is made:



PTC on left, sitting on button, right side is vent assy with vent layer intact:



PTC closeup:

[cy]

Holy cow! is that rust in a new cell?

Originally Posted by NewBie

The top of the cell, with the black washer off:



PTC closeup:

[NewBie]

Originally Posted by cy

Holy cow! is that rust in a new cell?

Unfortunately, yes, it appears so.


.