123 cell protection anatomy revealed

NewBie

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Warning!!!

Please do not attempt to do this, it can be very dangerous!

Some folks have argued about the existance of a PTC in 123 batteries. I'd like to assure folks that at least Duracell, Energizer, and Surefire all use PTC devices in their Primary Lithium Batteries.

ptc5.jpg


ptc4.jpg


ptc3.jpg


ptc2.jpg


ptc.jpg



I also took the PTC and measured it's resistance with temperature, and once it hit a certain temperature, it's resistance rapidly increases, to remove the load to a cell, in order to protect the user from a battery explosion.


Next, the rest of the cell:


ptc6.jpg


ptc7.jpg


ptc8.jpg


ptc9.jpg


ptc10.jpg


ptc11.jpg
 
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carrot

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

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

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Thanks for risking life, limb, and the wrath of product-liability attorneys everywhere to bring us this most informative photographic journey through lithium-primary cell construction!
 

NewBie

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

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


Heheh, you also find electroyte.


Some of the atypical stuff found in a Primary Lithium:

-Carbon Black
-1,2-Dimethoxyethane
-1,3-Dioxolane
-Graphite
-Lithium or Lithium Alloy
-Lithium Perchlorate
-Lithium Trifluoromethanesulfonate
-Lithium Trifluoromethanesulfonimide
-Manganese Dioxide
-Propylene Carbonate


Thermal degradation may produce hazardous fumes
of:
-manganese and lithium,
-hydrofluoric acid
-oxides
-carbon
-sulfur
-and other toxic by-products.

Under certain misuse conditions, and also by abusively opening the battery, exposed lithium can react with water or moisture in the air causing potential thermal burns or fire.

BATTERY CAN EXPLODE OR CAUSE BURNS IF DISSASSEMBLED, RECHARGED, OR EXPOSED TO WATER, FIRE, OR HIGH TEMPERATURE.
 
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kubolaw

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Wow, great stuff. Thanks NewBie!

It looks like the protective element is a sandwich of two metal disks separated by the PTC material. Does that mean that if a strong axial force is applied to the cell, the disks could short and bypass the protection? Or am I not looking at the pictures properly?
 

Burnt_Retinas

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Great pics,

Now add water to the grey electrode material, some of which is attached to the insulating liner. It's got the lithium. Keep the cell wrapped when adding water will give flames as it appears to ignite the insulating liner with the heat produced.

If anyone intends to pull apart a cell, please unwrap the layers and spill some water on it whilst outdoors. This will 'fizz' off the lithium, hopefully without any major fire. Not doing so may cause a fire hazard when disposed of in the trash should any lithium come into contact with moisture (most likely).

Chris
 

SilverFox

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Hello Newbie,

Excellent information, and my hat is off to you... Every time I have taken a cell apart it has caught fire. :(

Tom
 

KevinL

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Great job on the disassembly and the photography! That has been the best 'exploded view' of the interior of a cell that I have ever seen, bar none. :bow: :bow:

Lots of stuff inside the humble little 123 cell that we all use.
 

jsr

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a99raptors said:
Thanks and great work! What about the cheaper batteries like BatteryStation (Made in PRC) and Titanium?

Titanium states they have PTC. I too would like to know if BS 123As have PTC, but thus far, no one's been able to answer that when I ask.
I know Tenergy doesn't have PTC and these are the 3 low-cost brands I'm looking to purchase from in the future (when my current stock runs out).
 

a99raptors

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Saw the discharge curves over at the amondotech website regarding several 123 batteries that claim that titanium and batterystation batteries holds a greater charge for a longer time than any other batteries. I was just curious as to how true this is, considering their prices are also among the cheapest. Just wondering if they sacrifice reliability for lower prices.

http://www.amondotech.com/images/lithium_ion_battery/cr123a/123Comparison2A.jpg
 

Brighteyez

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You've made this posting in a rather authoritative demeanor. Do you know this for a fact, or was it just told to you (even if it was from Tenergy, as things might get lost in the translation, and I don't think the two ladies who answer the phones are real technical.)

I don't have any of their CR123 batteries, so I can't really tell for sure one way or the other either.

jsr said:
I know Tenergy doesn't have PTC
 

NewBie

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I will mention there is a little trick that is common in Lithium Ion Secondary cell manufacturing, that may be used for Primaries...

What they do is they over-crimp the PTC into the cell, with extra pressure/force. This actually causes the PTC current threshold to rise a bit. I've heard that you can get an extra amp out of them this way, before they kick off. I've seen several papers that warn against doing this, for a variety of reasons.

If you look, in one of the photos, you will see an indentation on the PTC ring, from the crimp. You do not want to "overdent" the PTC, as it will defeat it's function.

The vent ring with vent liner is in the bottom of the top, then the PTC is put in, then the button top (all with necessary insulators/liners), then the whole assembly is crimped shut by the outer negative can portion.

ptc12.jpg
 
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