# 18650 same size as Streamlight lithium ion battery?



## Mikellen (Sep 7, 2009)

I was wondering if an 18650 lithium ion battery is similar in size to a Streamlight 3.7 V lithium ion battery that is used inside my Streamlight Strion LED. 
The Streamlight battery is approximately 3/4 of an inch across (19.5mm) and 2 7/8 inches long (71mm).

I was hoping to use the Streamlight battery with a Malkoff MD2 which I have not purchased yet.

Thanks for any feedback.


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## Illum (Sep 7, 2009)

I'm pretty sure they are the same battery, 18650 is essentially the dimensions of the cell ~18mm x ~65mm 0 for cylindrical. 

the Strion lamp works well with 1x17670, 1x18650, and 1x18500 so I think its a safe assumption if the physical footprint matches those dimensions.


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## 45/70 (Sep 7, 2009)

I've often wondered about this ever since I bought my Strion several years ago. There is no doubt it's an 18650 cell. What I don't know is whether the protection circuit is inside the "pack" or in the light itself.

The "pack" is essential to use, as both the positive and negative contacts are arranged so they're at the lamp end. Until my "pack" needs replacement, which will be coming up soon, I haven't risked screwing it up to see how it works. Hopefully, it can be taken apart and a new cell swapped out without breaking anything.

Let us know if you figure it out Mikellen!

*Edited* to add that my Strion is the incan version.

Dave


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## Mikellen (Sep 7, 2009)

Illum said:


> I'm pretty sure they are the same battery, 18650 is essentially the dimensions of the cell ~18mm x ~65mm 0 for cylindrical.
> 
> the Strion lamp works well with 1x17670, 1x18650, and 1x18500 so I think its a safe assumption if the physical footprint matches those dimensions.


 

Being that the Streamlight battery is 1.5mm wider and 6mm longer do you think that is too much of a difference to fit inside a Malkoff MD2?

I placed an for a MD2 in the WTB section and I'll keep a look out in the WTS section for one. Hopefully I'll get one soon and see if my "experiment" will work. I don't think I'm ready to deal with all that's involved with traditional lithium ion batteries. (overdischarge, checking voltages, etc.)


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## 45/70 (Sep 7, 2009)

Mikellen, I don't think you understand. The Strion battery is nothing more than a conventional 18650 installed in a proprietary Streamlight battery case. Unless the LED version is different in some way, and I'm pretty sure it isn't, both the contacts are on one end of the cell pack. Have you ever looked at your Strion battery?

As it is, the only way you could utilize the Strion pack in the Malkoff is to remove the cell from it. Then you'd have a traditional lithium ion battery cell that you'd have to watch the voltage, avoid over discharging etc. whether protected or unprotected. Again, I'm not sure if the battery cell/case is protected, or the protection circuit is in the Strion itself, but you'd be way ahead to just buy a protected Li-Ion 18650.

It seems to me you're going to a whole lot of trouble for nothing.

Dave


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## Mikellen (Sep 7, 2009)

45/70 said:


> Mikellen, I don't think you understand. The Strion battery is nothing more than a conventional 18650 installed in a proprietary Streamlight battery case. Unless the LED version is different in some way, and I'm pretty sure it isn't, both the contacts are on one end of the cell pack. Have you ever looked at your Strion battery?
> 
> As it is, the only way you could utilize the Strion pack in the Malkoff is to remove the cell from it. Then you'd have a traditional lithium ion battery cell that you'd have to watch the voltage, avoid over discharging etc. whether protected or unprotected. Again, I'm not sure if the battery cell/case is protected, or the protection circuit is in the Strion itself, but you'd be way ahead to just buy a protected Li-Ion 18650.
> 
> ...


 


Ahh.... O.K. I think I understand now. I've never seen an 18650 or 17670 battery before so I didn't realize the Streamlight is using an 18650 battery only that its just wrapped in Streamlight's own type of casing.
So now I understand that using the Streamlight battery in the MD2 would not be feasible. 

Thanks for the information.


Here are a couple pictures showing both ends of the Streamlight Battery.


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## csadzuki (Nov 22, 2009)

Hello,

I recently bought a used Streamlight Strion (incan model), and the battery was dead. Since it appears to be difficult to buy a reasonably priced genuine Streamlight replacement battery here in Japan, I'm thinking about replacing the Li-Ion cell inside myself.

Here are some disassembly photos:


























The cell is an LG Chem. cell. At the end terminals, I get 0.00 V reading.
At the battery (I think), I get 2.65 V. I think I will properly dispose of the cell itself, and replace it with an Ultrafire or similar cell.

Do you fellow CPFers think that would be alright? :thinking:


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## Illum (Nov 22, 2009)

nice...so the protection circuits built into the bottom of the cell

some proprietary 18650s has soldered contacts that may require you to desolder them to take it out, I think this might be the case

0.00V might hint that the PCB tripped
have you tried measuring voltage across pins of V+ cell and V- cell instead of V+ batt and V- batt?


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## 45/70 (Nov 22, 2009)

Thanks for the pics csadzuki! :thumbsup:

Keep us informed on your replacement project. I've always wondered how to get the "pack" apart and remove/replace the 18650 without destroying so many components that it wouldn't be worth trying.

My Strion's cell is on the borderline of EOL. I'd like to try to replace the cell.

Thanks again,

*EDIT:* Just curious, what is the length of the actual 18650?

Dave


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## csadzuki (Nov 23, 2009)

Illum said:


> nice...so the protection circuits built into the bottom of the cell
> 
> some proprietary 18650s has soldered contacts that may require you to desolder them to take it out, I think this might be the case
> 
> ...



The cell seems pretty standard, I will put up pictures in a minute. The positive contact appeared to be soldered or otherwise coupled together with the flat contact wire.

At the V+batt and V-batt, I got 2.65-2.66 V reading. The plastic holder also has "2004" printed on it, so I guess I should consider the cell dead and dispose of it properly for safety.


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## csadzuki (Nov 23, 2009)

45/70 said:


> *EDIT:* Just curious, what is the length of the actual 18650?
> 
> Dave



I do not have the proper tools to perform accurate measurement, but with a simple ruler, I measured 64.5mm length.

Diameter seems to be 18.78mm.


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## csadzuki (Nov 23, 2009)

New pics. Sorry I did a poor job at removing the positive battery contact wire, but I was afraid to unsolder it. 



























The plan is to ditch the protection circuit and replace the cell with a protected AW 18650 cell. (This way I don't have to bother with reassembling the protection circuit nicely, and I probably don't have to worry about the possibly longer cell size. Also it will be easier to replace the cell in the future.) How does that sound?


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## 45/70 (Nov 23, 2009)

csadzuki said:


> The plan is to ditch the protection circuit and replace the cell with a protected AW 18650 cell. (This way I don't have to bother with reassembling the protection circuit nicely, and I probably don't have to worry about the possibly longer cell size. Also it will be easier to replace the cell in the future.) How does that sound?




More great pics, csadzuki.

It sounds good to me. One thing I wonder about, does the existing protection circuitry contain any components that relate to the charging of the light in the cradle? I thought about doing the same as you suggest, but I don't know enough about circuitry to tell from your pictures. :candle:

Dave


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## Illum (Nov 24, 2009)

45/70 said:


> More great pics, csadzuki.
> 
> It sounds good to me. One thing I wonder about, does the existing protection circuitry contain any components that relate to the charging of the light in the cradle? I thought about doing the same as you suggest, but I don't know enough about circuitry to tell from your pictures. :candle:
> 
> Dave



From the way the cell assembly looks prior to your disassembly, there is no way the flashlight can use a AW18650 directly because the anode contact is on the side rather than center and no contact at rear, from the looks of it its on the side as well. I suppose you can convert it to where it can use an AW cell but then you lose the charging capability and requires individual charging of cells. 

I'd consider otherwise, a unprotected 18560 will last awhile provided the protection circuit is tolerant enough of a battery with slightly different capacity than the one it was designed for.
plus the strion is not designed to be opened daily, you'll wear out the body charging cells individually


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## 45/70 (Nov 24, 2009)

Ya got a point there Mr. Nation (whatever happened to that anyway? ).

I'm hoping csadzuki can figure this all out! I hate spending $34.95 for a replacement battery for mine. In this day and age of 200 lumen LED keychain lights, it seems kinda silly to spend that much for a 70 lumen incan (which again, mine is), but I really like it and use it quite a bit.

Dave


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## csadzuki (Nov 25, 2009)

Illum said:


> From the way the cell assembly looks prior to your disassembly, there is no way the flashlight can use a AW18650 directly because the anode contact is on the side rather than center and no contact at rear, from the looks of it its on the side as well. ...



Sorry, actually there is one thing that the pics don't show very well... inside there is a nice circular contact plate for the battery at the top which is wired to the outside middle contact (I think). A part of it is visible here:






So after removing the unneeded stuff from there, I think that the + of the AW cell can make direct contact with the round contact plate. I'm planning to use the original flat wire to connect the negative of the battery to the outer top contact. The battery will be held in place by the plastic casing and some foam at the bottom.

Sorry, actually I did not have time yet to see whether this would actually work, maybe this weekend. I also didn't have time to verify all the above statements about what is connected to what, so if anyone decides to go ahead with this, please make sure you measure everything!




45/70 said:


> More great pics, csadzuki.
> 
> It sounds good to me. One thing I wonder about, does the existing protection circuitry contain any components that relate to the charging of the light in the cradle? I thought about doing the same as you suggest, but I don't know enough about circuitry to tell from your pictures. :candle:
> 
> Dave



I think it should be fine, the cradle controls the charge, and the PCB is only there for protection. But I will post a close-up pic of the protection PCB this weekend and maybe we can google for the IC to see what it does.


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## hamid (Nov 25, 2009)

Hi every body,

I have two kind of Li-ion batteries (18650-26A samsung and 18650v- sony).
I want to disassemble them. But when I start to do this in a glove box (a box full of argon that only hands that put glove on could inter it) battery start to be warm. Does any body know which instrument I should use? and what points I should consider.


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## csadzuki (Nov 29, 2009)

hamid said:


> Hi every body,
> 
> I have two kind of Li-ion batteries (18650-26A samsung and 18650v- sony).
> I want to disassemble them. But when I start to do this in a glove box (a box full of argon that only hands that put glove on could inter it) battery start to be warm. Does any body know which instrument I should use? and what points I should consider.



Hello, and welcome to CPF :wave:
I'm not sure I understand what you are trying to achieve here, but I would *strongly recommend against* trying to disassemble Li-Ion batteries. Li-Ion batteries can be *very dangerous* when not handled properly (vent, burst into flames, explode, etc.).

In any case, I'm afraid that you won't get an answer to your question in this topic. You could try to open a new topic.


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## csadzuki (Nov 29, 2009)

Back on topic, I have a few more pictures of parts and the "completed" assembly.

First, here is a pic of the + battery contact I mentioned before:





Next, here is a pic of the electronics:





It's not readable in the pic, but the IC reads:
347M
3T5B
F7311

Anyone can identify the IC? 

* * *

I don't have the AW cell yet, so I used the original cell as an example.
Here is how the components fit together:










(I made the negative contact out of solid copper wire and a lot of solder.  As you can see, it's not pretty. :duh2: I'm sure you guys can do a much better job! )


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## 45/70 (Nov 29, 2009)

Thanks for the update csadzuki.



csadzuki said:


> (I made the negative contact out of solid copper wire and a lot of solder.  As you can see, it's not pretty. :duh2: I'm sure you guys can do a much better job! )



How pretty it is doesn't really make any difference. Nobody is ever going to see it, in a Strion, except yourself, the next time you replace the cell! As long as it works, who cares.

I'm curious what the PCB does. As I said, I'm not familiar enough with electronic circuits to be able to tell whether it is simply a protection circuit, or is involved with some other function as well.




hamid said:


> But when I start to do this in a glove box (a box full of argon that only hands that put glove on could inter it) battery start to be warm.



As csadzuki pointed out, this is off topic, but for safety reasons I'd like to point out that your argon filled glove box will not prevent the cells from "venting with flame". All of the necessary elements for combustion/reaction are contained within the chemistry of the cell itself.

Dave


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## csadzuki (Nov 29, 2009)

45/70 said:


> Thanks for the update csadzuki.
> 
> 
> 
> ...



Thanks. 

I'm also curious what the PCB does. A quick google search for the IC came up with this datasheet. I can't really figure out how the circuit works... :shakehead
Anyone?

Anyway, I'm not worried much because the Strion Charger (model no. 74102) says: "OUTPUT: REGULATED 4.2V", which should be fine for Li-Ion. Plus, the AW cells have very good protection.


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## Illum (Nov 29, 2009)

csadzuki said:


> Next, here is a pic of the electronics:
> 
> 
> 
> ...



347M is a Positive Overvoltage Protection Controller
consult NCP347 datasheet
Three caps, three resistors
one SOT-23 component marked A6 and one SO-6[?] chip hmm:thinking:

that SOT-23 "A6" is a signal diode
See Fairchild BAS16 Datasheet

this circuit prevents the cell from being overcharged, so its in the place between the li-ion and the unregulated charger
Typical application of the NCP347, obviously NOT whats being used here but sure looks like a battery charger to me:


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## csadzuki (Dec 1, 2009)

Thanks for the analysis Illum, I guess this means that replacing the PCB with the AW cell's built-in protection should be fine, right? 

Here are a few more pics, I hope they help (my camera OR my scanner don't have nice macro modes :sigh:


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## Illum (Dec 1, 2009)

that depends on the output of the charger. AW circuits are designed to be charged with 4.2V chargers that may or may not be sloppy in termination.

If the charger is a voltage greater than 4.2V, then it could also mean there is sufficient overhead in the 347M to accept the voltage or the circuitboard may be acting as a step-down prior to the charging/termination IC, as the schematic I've posted shows.

the 347M appears to be where the step-down occurs, because its not the actual charger

I noticed the 6 pin chip reads "KNL 1" 
Only hit exists as a High-Speed Microcontroller made by Dallas Semi
EDIT: check "DS83C323-KNL" Datasheet

Since the 347M exists on the board, it would mean the input voltage can be higher than 4.2V, breaking compatibility with AW circuits.
Sorry bud, looks like streamlight did its homework


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## csadzuki (Dec 2, 2009)

Illum said:


> ...
> 
> Since the 347M exists on the board, it would mean the input voltage can be higher than 4.2V, breaking compatibility with AW circuits.
> Sorry bud, looks like streamlight did its homework



Thank you. Well, that doesn't sound so good.  In the worst case I can put back the original PCB and use an unprotected cell (and put the AW 18650 into my Olight M20 ).

*Could someone please measure the actual voltage of the charger at the cradle?* (I do not have AC adapter for the charger right now.) It's very simple if you have a DMM, just make sure you don't short out the two contacts. Thanks!


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## 45/70 (Dec 2, 2009)

Hey csadzuki. I did a quick, no load voltage check of my Strion cradle. I'm using the DC version, as I never had the AC setup.

I am powering the cradle @ 13.8 Volts with a 30A linear PS I use for my Ham transceivers. Using an old RatShack DMM (22-174), the voltage was not constant, swinging from about 5.1 to 5.7 Volts which, I guess, denotes some AC getting through the PS?. Hummm.

Hope this helps.

Dave


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## csadzuki (Dec 26, 2009)

45/70 said:


> Hey csadzuki. I did a quick, no load voltage check of my Strion cradle. I'm using the DC version, as I never had the AC setup.
> 
> I am powering the cradle @ 13.8 Volts with a 30A linear PS I use for my Ham transceivers. Using an old RatShack DMM (22-174), the voltage was not constant, swinging from about 5.1 to 5.7 Volts which, I guess, denotes some AC getting through the PS?. Hummm.
> 
> ...



Hi Dave,

Thank you for the measurement :bow: and sorry for the late reply.

Unfortunately it seems that my plan with the AW cell is not the best for this charging configuration. So I will call this project canceled, sell the light and let the new owner worry about finding a replacement battery. 

In summary, points learned:


It seems to be possible to simply replace the 18650 cell inside the battery.
The best way is probably to use an *unprotected 18650 Li-Ion cell* and *keep the original protection circuit*.
If anyone gives it a try, I would love to see the results in this thread.


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## 45/70 (Dec 26, 2009)

Aww, that's too bad csadzuki. I had high hopes you would figure all this out so I wouldn't have to. 

As it is, I have too many light projects in the works that are stagnate right now. I do want to keep my Strion going, if at all possible. It's my only incandescent light that is not a hotwire and, as I said, as inglorious as it is, compared to modern LED lights, I still find it very useful.

_If_ I ever get around to trying it, I'll report in here.

Dave


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## Illum (Jan 12, 2010)

45/70 said:


> Ya got a point there Mr. Nation (whatever happened to that anyway? ).



My name was shortened with a special request to [email protected], I did not know at the time that user name registers spaces, but without spaces it looked odd, so i had the latter half lopped off


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## Strion LED (Dec 21, 2013)

Illum said:


> My name was shortened with a special request to [email protected], I did not know at the time that user name registers spaces, but without spaces it looked odd, so i had the latter half lopped off



Newbie interesting reading.
I just bought a new Strion HL.
I was hoping to find an alternative to the 74157. 
You guys did a lot of the leg work. 
Sucks SL kind of used a " proprietary" battery.
Although it looks like they are just adding their own window dressing to a 18650 cell.
But a lot of BS to go through to make this work, plus the hazards involved with dissecting the LI I cell

If anybody has any updates to this post and did find an alternative battery and a good external charger sure would be interested to see what you came up with.

Thanks


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