# Photos of Protected Lithium Batteries



## LuxLuthor (Jul 10, 2007)

_I made a post in Sosa's thread about the exploded battery in his Fenix light (nothing wrong with the Fenix), and got 3 PM's from people recommending I make this thread showing the images so people understand what a "Protected" & "Unprotected" Lithium battery looks like. _*If the moderators feel this is cross posting, please close the topic.

*


KingGlamis said:


> I'm a relative newbie. Can you explain the difference between protected and unprotected cells? I have RCR123As with the name Powerizer on them. Doesn't say where they were MFG-ed. But they do have a plastic "wrap" on them and what appears to be two vent holes on the positive end. Are these protected cells?



It's a very good and important question. When we say "Protected" we mean a separate computer chip that is added and gives a cutoff (breaks the circuit in the battery from completing) if the voltage goes too low, the voltage goes too high, the current amperate goes too high, and the cell temperature rises too high.

I sacrificed a *Year Old (Current improved model has new features)* of AW's 14670 cell to show you exactly what this means.

Click on the thumbnail images below. AW starts with a normal UNprotected cell in blue plastic which he also sells. These have the vent holes which help release pressure if the temperature rises, and gas expands. That means the starting blue, unprotected cell just has high temp venting protection (as far as I know).

Now note there is a thin computer chip on the bottom under a metal disc. One end is welded to the bottom (Negative Terminal) of the blue battery, and the other end uses a thin contact strip to run along the side and attach on the top Positive terminal.

It is this computer chip that does all the important sensing and interruption of the circuit, otherwise the blue cell is an unprotected cell. The additional black shrink wrap and label are added to keep the components anchored and insulated. You can feel and see the space at the bottom of the bottom of a protected AW battery where the PTC circuit is locate4d.
_*
Please note AW's improvements on current version which parallel those of Pila in his post #9 of this thread. Excellent News because I have had a number of my Li-Ion's drop to the floor.*_

If the ones you are buying for other lights, such as R123 do not specify that they have this kind of protection, and especially if you don't see the circuit gap and feel the thin strip along the side, then it's pretty safe to assume you are not using protected Lithium cells. I hope this illustrates more clearly what a "Protected" battery actually means.



 

 

 





 

 

 




Finally, if I remove the blue wrapper you see the metal canister with the plastic circle on top that separates the Negative entire outside and the inner, middle top positive end. It is a shiny, stainless steel casing, it just photographed a darker color.


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## LuxLuthor (Jul 10, 2007)

As my images show. There is a difference between a "PTC" "Positive Temperature Coefficient" vent holes (that elgarac mentioned above), and this electronic voltage/amperage circuit protection which is put on a computer chip. Many hear PTC as "Protection Circuit" which it is not. 

Very few if any Li-Ion cells will have a circuit added like AW does. One other very high quality Lithium cell brand that does is Pila which is more expensive. However, in addition to many other demanding specifications, notice that Pila uses a white plastic ring to give better shock/impact damage to the chip and components use a layer of thick tape under metal end plate to insulate the chip from a fall. Stop and think about what happens if a battery falls on the bottom end in terms of crushing/damaging the chip components, which is yet one more thing to be careful with. *(Most, if not more of these same features have now been added by AW's improved, current and more affordable priced brand, which is great news)*


Click on Thumbnails


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## Raoul_Duke (Jul 10, 2007)

Nice pics lux, and thanks for doing this. ( Althought I have already pulled apart li-ions, and knew this, I never thought it would have been a good Idea to post pictures to educate others.

In addition to dropping the cells on the circuits, squeesing to many cells into a small flashlight body risks damaging the protection cuircuit. Also a strong / stiff tailcap spring has been known to wreck the protection curcuit on Protected cells.

Now that you have bare cells, have you any plans to damage them further, to demonstrate the hazard involved in peircing the cells etc?

( That was said tounge in cheek BTW)

Please dont hammer a nail through them, but I have picked up from your post you own guns, so prehaps shooting them from a safe distance would be fun with a video cammera recording the results


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## JetskiMark (Jul 10, 2007)

Excellent pics and info LuxLuthor. I already knew the info but I have never actually seen a protected AW or Pila cell disassembled. Very informative thread.

Regards,
Mark


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## AW (Jul 11, 2007)

Lux,

The picture you shown is the earliest version of my cells ( more than 1 year ago ). My new cells have a different construction now.

AW


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## carbine15 (Jul 11, 2007)

AW said:


> Lux,
> 
> The picture you shown is the earliest version of my cells ( more than 1 year ago ). My new cells have a different construction now.
> 
> AW



I have two questions:

1. Why does the circuitry always go on the bottom of the cell. It seems to me that there is no need to create another negative path when one exists that is the under wrapper. If you could make the circuit integral with the button top of the cell, you could eliminate an entire layer of insulation and eliminate the need for the contact thread (wire running from top to bottom) that so often makes protected cells not fit in some applications. 

2. Wouldn't it be cheaper and more effective against drops if the entire circuit was potted with non-conductive epoxy?

Maybe the reason this isn't done is because of the vent holes that need to be there just in case the cell gets angry. I'm sure there's a way to preserve the holes _and _mount the circuit on the top thus saving valuable width.


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## AW (Jul 11, 2007)

carbine15,

I think you have already answered your own question. There is no way to built an integral protection circuit with the vent assembly without blocking the vents or eliminate the ground path. The extra thickness of a protected cell comes from the bump of the wrapper. However, the industrial grade shrink wrap is still the toughest and provide the best protection against abrasion and wear compared to consumer wrappings.

AW


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## LuxLuthor (Jul 11, 2007)

AW said:


> Lux,
> 
> The picture you shown is the earliest version of my cells ( more than 1 year ago ). My new cells have a different construction now.
> 
> AW



Yeah, I know you made a change...but I didn't want to sacrifice a new cell! LOL! I stopped using these old 14670's and I used another to verify my contact welder worked properly with it.

What is the improvement....better protection of the PCB chip? I mainly just wanted to show the concept of how it is made, where the separate pcb is located, and what makes it different from unprotected. 

I highly recommend AW's cells.


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## AW (Jul 11, 2007)

Since then I have upgraded the protection IC and insulation material. The new insulation material is cut to surround and support the pcb from being crushed ( same thickness with pcb components ). It has a high flash point ( 300 degree C ) and won't deform/melt like plastic above 80 degree C. The insulation for the nickel connecting strip has been replaced with heat resistant tape ( 260 degree C ).


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## LuxLuthor (Jul 12, 2007)

AW, that is really great news. *I edited my above posts to reflect these improvements.* I only did this to illustrate what a protection circuit looks like, so I'm sorry I didn't sacrifice a new model for all the shots....but I'm using those !!!


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## Fallingwater (Jul 12, 2007)

Thanks for the pics. I'll be removing the step-down converter from a 3v RCR2 cell shortly, and I already had an idea of how to do it, but your pics confirmed it.


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## LuxLuthor (Jul 15, 2007)

I just happened to have one of the *newer improved AW 14670 Li-Ion cells *that I decided to sacrifice because I kept wondering just what secrets it had over the older AW version.

Here is one more "contribution to the cause" so no one else is left wondering about the nice enhancements AW made. It shows his willingness to listen and improve the quality of his batteries, in addition to his lower pricing and excellent service. :thumbsup:

The red spacer is about 1.15mm. The contact strip is insulated from body with 1mil (0.001 inch) Kapton tape.

Click on thumbnails for high res.


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## PhotonAddict (Jul 15, 2007)

Lux, thanks for sacrificing yet another one for the "cause". 
btw: Is the last photo a picture of board with the protection circuit? ie., the negative contact of the battery?


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## LuxLuthor (Jul 15, 2007)

PhotonAddict said:


> Lux, thanks for sacrificing yet another one for the "cause".
> btw: Is the last photo a picture of board with the protection circuit? ie., the negative contact of the battery?



Yes. There is an outside metal disc covering the back of the PCB (Printed Circuit Board) at the NEG terminal end of the battery. Don't know what that glue is that attaches it...maybe Arctic Silver Epoxy?


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## LuxLuthor (Dec 18, 2007)

BTT


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## RGB_LED (Dec 18, 2007)

LuxLuthor, thanks for sacrificing your batteries for the cause and for providing this information. I have used AW's 750mAh and LiFePO4 RCR123's, 17670's and 18650's for about a year now and, while I have had no complaints, I had been contemplating getting other brands of batteries but this is just further confirmation that there is no need as AW's are the best out there. 

This is comforting information as there have been several threads in the past year about exploding CR123's - primaries and from other manufacturers. Thanks AW, for actively improving your batteries to make them better and safer for us all. :thumbsup:

I think I'll be putting in a new order soon for more AW batteries... :santa:


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## radellaf (Dec 18, 2007)

So on the RCR front, is it correct that there are like four different kinds the same size?
1. Straight unprotected 3.7 RCR123
2. Protected version
3. Regulated to 3.0V version (i assume ckt also protects)
4. LiFePO4 3.2V

Is #4 a replacement functionally for #3? Where the chemistry makes it need neither voltage reduction or protection circuitry?

I hope so, as I want to use two, safely, in a 2xCR123 Inova 3W LED (T3 i think).


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## LuxLuthor (Dec 19, 2007)

Last I checked on the topic, those were the RCR 123's I was aware of. There are pro's and con's to the #4, including safety & reduced capacity that makes it not be an identical performance trade.


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## katsyonak (Dec 19, 2007)

Thanks LuxLuthor, that's an interesting thread.


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## LuxLuthor (Jan 4, 2008)

Had a number asking me about the length of AW's C Li-Ion with protection circuit as compared to the Kai unprotected model. I measure AW's length 53.5mm including button, or 51.5mm to top adjacent to button.


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## radellaf (Jan 9, 2008)

LuxLuthor said:


> There are pro's and con's to the #4, including safety & reduced capacity that makes it not be an identical performance trade.



For the Inova light I chose LiPO4s, so I assume I'm getting a slightly safer cell, with a lower capacity, than a regulated RCR . I couldn't find the regulated ones that day...

I don't care a great deal about runtime, so my only worry at this point is whether the extra .2V (x2 in this light) is going to stress the electronics or the 3W LED.

My new concern is now whether my Fenix L0D with 500mA rated (250mAh tested) regular Li Ion 10440s is going to explode. So far Ultrafire has said "thanks for the info" on the capacity shortcoming, but has neither offered to replace the cells, nor been forthcoming with a datasheet or other yea/nay confirmation about the safety of 1A loads.


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## etc (Oct 17, 2008)

Given this old thread -- AW's 18500 seem to have a higher mAh rating, 1500 mAh vs. 1400 mAh for Pila's 300P.

Is there any tangible reason why one might prefer Pila vs. AW?


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## c0t0d0s0 (Dec 26, 2008)

In my experience, AW 18500 cells suck.

Out of 4 AW 18500 cells that I had, 3 failed: 2 leaked electrolyte, 1 woudn't hold the charge. Different batches, too. I switched to Ultrafire in this size.

Note that I have a bunch of AW cells in other sizes (18650, 17670, RCR123) and never had any problems with those. It's just the damn 18500 cells.


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## LuxLuthor (Dec 29, 2008)

c0t0d0s0 said:


> In my experience, AW 18500 cells suck.
> 
> Out of 4 AW 18500 cells that I had, 3 failed: 2 leaked electrolyte, 1 woudn't hold the charge. Different batches, too. I switched to Ultrafire in this size.
> 
> Note that I have a bunch of AW cells in other sizes (18650, 17670, RCR123) and never had any problems with those. It's just the damn 18500 cells.



I never got the one FiveMega light that used this new 18500 cell, but if what you are saying is true (and I believe your report), AW would certainly take care of the situation. 

I had a batch of 17670 cells that did not have the proper performance over a year ago, and AW resolved it to my full satisfaction. There is a substantial reservoir of excellent customer service that AW has built up, and worth remembering if a rare problem occurs. In other words, I have always seen him favorably resolve issues like this.


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## Helstar (Dec 29, 2008)

So, is this a concern only for rechargeable? I am just getting into the whole CR123a lights. I was going to buy a butt load of Rayovacs from Battery junction or maybe the Duracell's, anyway do I need to worry? Or like I said is this just for rechargeable????


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## LuxLuthor (Dec 29, 2008)

Helstar said:


> So, is this a concern only for rechargeable? I am just getting into the whole CR123a lights. I was going to buy a butt load of Rayovacs from Battery junction or maybe the Duracell's, anyway do I need to worry? Or like I said is this just for rechargeable????



The protected circuits added to cells as shown in this thread are related to rechargeable LiPo or Li-Ion cells. 

There are other problems with primary Lithium (use once) cells...particularly if mixed brands, and/or cheap brands, and/or dissimilar voltage charge levels are combined in a light.


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## chiphead (Dec 30, 2008)

LuxLuthor!

This is fantastic, my first 18650 cells will be here by week's end and I've wondered just what the (bleep) I've gotten myself into! This is most educational! But just what are unprotected cells good for?

chiphead


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## Yoda4561 (Dec 30, 2008)

Unprotected, lithium cobalt cells are used in large battery packs with a protection circuit built into the "pack" instead of each individual cell, or in a device with a built in protection circuit. Also in stuff where safety is a secondary concern to maximum power density ( hobby R/C ).


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## LuxLuthor (Dec 30, 2008)

Yeah, as Yoda says. Some of us who have learned proper use and care of Lithium Ion batteries may use unprotected for certain flashlights that may need just a bit more current output than the AW/Pila 5.5Amp output limited protected cells.

We realize most of the concern with unprotected Lithium Cobalt cells is from imbalanced cells, and mostly when charging. It's not that unprotected cells cannot be used...rather the user needs to be aware of the increased risks and be willing to take appropriate steps to manage them.

If you read the posts in this battery section, you realize how many users still do not have a proper understanding of Lithium Batteries. So the general guideline of using Protected Lithium Cobalt Ion cells is the safest message that can be sent out.


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## chiphead (Dec 30, 2008)

LuxLuthor said:


> Yeah, as Yoda says. Some of us who have learned proper use and care of Lithium Ion batteries may use unprotected for certain flashlights that may need just a bit more current output than the AW/Pila 5.5Amp output limited protected cells.
> 
> We realize most of the concern with unprotected Lithium Cobalt cells is from imbalanced cells, and mostly when charging. It's not that unprotected cells cannot be used...rather the user needs to be aware of the increased risks and be willing to take appropriate steps to manage them.
> 
> If you read the posts in this battery section, you realize how many users still do not have a proper understanding of Lithium Batteries. So the general guideline of using Protected Lithium Cobalt Ion cells is the safest message that can be sent out.


You don't have to tell me but once! By the way, where did you get those cells you did the autopsy on?

chiphead


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## LuxLuthor (Jan 14, 2010)

Bumping


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## Zalupok (Feb 21, 2010)

I have taken in a parts the one by accident. Is it possible to repair it? Will it work fine?


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## Mr Happy (Feb 21, 2010)

Zalupok said:


> I have taken in a parts the one by accident. Is it possible to repair it? Will it work fine?


Too funny...



Oh, and welcome to CPF! :welcome:


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## Mik (Feb 21, 2010)

Zalupok said:


> I have taken in a parts the one by accident. Is it possible to repair it? Will it work fine?


 
Oh yeah, that'll buff right out! :wave: NICE!


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## DM51 (Feb 21, 2010)

Welcome to CPF, Zalupok 

LOL @ your pics, but they are much too large. Please re-size them to comply with Rule 3. The max permitted size is 800 x 800 pixels (yours there are 1280 x 960)

Mik, there's no need to include the whole post with all the pics in the quote. Please edit it out.


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## Bronx68 (Sep 15, 2010)

We are presently designing a led UV curing station. The circuit in the unit requires a voltage above 8 volts and less that 24 volts. It draws 350 ma (.35 amps) with a 9 volt input. We need to add battery operation to these units. The batteries need to be rechargeable and will also need a battery charger. What do you recommend for batteries and a charger? The batteries can be removed from the unit to go in the charger.

We are looking for medium to low cost battery solution. The unit is turned on for 30 seconds at a time. Something over 30 to 40 exposures (on seconds each exposure) should be adequate between recharges


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## LuxLuthor (Sep 22, 2010)

Bronx68 said:


> We are presently designing a led UV curing station. The circuit in the unit requires a voltage above 8 volts and less that 24 volts. It draws 350 ma (.35 amps) with a 9 volt input. We need to add battery operation to these units. The batteries need to be rechargeable and will also need a battery charger. What do you recommend for batteries and a charger? The batteries can be removed from the unit to go in the charger.
> 
> We are looking for medium to low cost battery solution. The unit is turned on for 30 seconds at a time. Something over 30 to 40 exposures (on seconds each exposure) should be adequate between recharges



I think you may have wanted to start a separate thread, since your post has nothing to do with this topic. Also, regular font size would be easier to read.


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