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Thread: General Li-ion safety

  1. #61
    Flashaholic* samgab's Avatar
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    Default Re: New section added 12/26/11: Li Ion beginner primer

    Quote Originally Posted by N162E View Post
    Maybe I'm just plain stupid, for sure not on a par with you genius' I guess I always thought that a "Beginners Primer" was supposed to answer questions not create them. You refer to the periodic table, I always thought that was elements, not mixtures or compounds.
    HKJ is correct. Anyone with very basic high-school knowledge of chemistry would recognise those symbols such as LiFePO4; Lithium, Ferrum (Iron), (Phosphorus, + Oxygen 4) etc.
    It seems that the role of this thread doesn't appear to be to teach basic chemistry, but rather a basic guide to how to use and treat li-ion cells and batteries.
    The OP can correct me if I'm incorrect in that...

    Edit: lol, both posts above beat me to it also
    Last edited by samgab; 12-27-2011 at 04:07 PM.
    In date order, as far as I can remember: Mag 4D LED, LL P14, Fenix LD20 R4, 47s Preon 2 R5 red, 47s Quark Mini AA S2, Fenix TK35 XM-L T6, 4Sevens ReVO SS S2, Maha MH-C808M, Maha MH-C9000, 47s Single Bay Li-ion charger, Zebralight SC600 XM-L U2, Fenix TK70, iCharger 206B, Sunwayman D40A...

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    Default Re: New section added 12/26/11: Li Ion beginner primer

    Okay, 12/27/11, I added some words to address battery chemistries and the use of a DMM. Notes as to where those sections are, are at the top of the primer. Thanks again for the help in making this better.


    Quote Originally Posted by samgab View Post
    HKJ is correct. Anyone with very basic high-school knowledge of chemistry would recognise those symbols such as LiFePO4; Lithium, Ferrum (Iron), (Phosphorus, + Oxygen 4) etc.
    It seems that the role of this thread doesn't appear to be to teach basic chemistry, but rather a basic guide to how to use and treat li-ion cells and batteries.
    The OP can correct me if I'm incorrect in that...
    The initial reason I wrote this, is because a number of times I've seen (mostly on other forums) an interaction along the lines of:
    poster 1: what batteries do you run in that?
    poster 2: I'm running 16340s
    poster 1: what's that?
    poster 2: Lithium rechargeables, same size as a CR123
    Poster 1: cool, I'll pick some up and try them out. Those SchmuckFires on eBay look nice & cheap.

    My concern was the number of folks walking into Li Ions who had no idea whatsoever of the risks -- and I don't blame them, chances are no other batteries they've dealt with expose the same risks, even the Li Ions in their laptop are (usually) managed by the hardware in that laptop and the charger, not managed by the user themselves. So I wanted to write something we could point brand new users at, in a short enough format to be digestable in a single sitting, that impresses upon them the risks of Li Ions, tells them the basics of good handling, and of course lets them know the advantages. Of course, once this is all written, it is an incredible temptation to go from a 2-page primer to a more detailed reference document, since it's nice to have all that info in the same place. And therein lied my concern about explaining what (say) IMR means. I've included it, but I really want to make sure that information isn't just a distraction, that the user can simply look up on their own as they get more advanced.

  3. #63
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    Default Re: New section added 12/26/11: Li Ion beginner primer

    Quote Originally Posted by Joe Talmadge View Post
    Okay, 12/27/11, I added some words to address battery chemistries and the use of a DMM. Notes as to where those sections are, are at the top of the primer. Thanks again for the help in making this better.




    The initial reason I wrote this, is because a number of times I've seen (mostly on other forums) an interaction along the lines of:
    poster 1: what batteries do you run in that?
    poster 2: I'm running 16340s
    poster 1: what's that?
    poster 2: Lithium rechargeables, same size as a CR123
    Poster 1: cool, I'll pick some up and try them out. Those SchmuckFires on eBay look nice & cheap.

    My concern was the number of folks walking into Li Ions who had no idea whatsoever of the risks -- and I don't blame them, chances are no other batteries they've dealt with expose the same risks, even the Li Ions in their laptop are (usually) managed by the hardware in that laptop and the charger, not managed by the user themselves. So I wanted to write something we could point brand new users at, in a short enough format to be digestable in a single sitting, that impresses upon them the risks of Li Ions, tells them the basics of good handling, and of course lets them know the advantages. Of course, once this is all written, it is an incredible temptation to go from a 2-page primer to a more detailed reference document, since it's nice to have all that info in the same place. And therein lied my concern about explaining what (say) IMR means. I've included it, but I really want to make sure that information isn't just a distraction, that the user can simply look up on their own as they get more advanced.
    Cheers.
    Maybe a bit about sizing conventions and nomenclature would be handy? Eg: 16340, 10440, 14500, 18650, 32600, 32900, and so on. About how it basically reflects the diameter and length, but not always exactly, there are tolerances either side of the exact measurements, plus extra length for a PCB in some cases. And also about how they don't always come with a button top, that some have tabs, or are just flat because they are designed for manufacturers to task in battery packs.
    In date order, as far as I can remember: Mag 4D LED, LL P14, Fenix LD20 R4, 47s Preon 2 R5 red, 47s Quark Mini AA S2, Fenix TK35 XM-L T6, 4Sevens ReVO SS S2, Maha MH-C808M, Maha MH-C9000, 47s Single Bay Li-ion charger, Zebralight SC600 XM-L U2, Fenix TK70, iCharger 206B, Sunwayman D40A...

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    Default Re: New section added 12/26/11: Li Ion beginner primer

    Yes, really good info.

    Okay, I'm getting some feedback about the issue I was concerned about -- mission creep of the primer from an easily-digestible raw-beginner how-to, to something a bit more detailed and usable as a reference. If I get more feedback like that, I'm going to re-structure the document in two parts: part 1, which has the most critical & basic beginner information, and part 2, which handles a lot of what we've been discussing this week regarding abbreviations and chemistries, the detail on what the numbers mean, etc. What do you all think?

  5. #65
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    Default

    Quote Originally Posted by Joe Talmadge
    Yes, really good info.

    Okay, I'm getting some feedback about the issue I was concerned about -- mission creep of the primer from an easily-digestible raw-beginner how-to, to something a bit more detailed and usable as a reference. If I get more feedback like that, I'm going to re-structure the document in two parts: part 1, which has the most critical & basic beginner information, and part 2, which handles a lot of what we've been discussing this week regarding abbreviations and chemistries, the detail on what the numbers mean, etc. What do you all think?
    Personally, I think that is a great idea.
    You could have both parts as a single post in the first post of the thread, with a horizontal rule line dividing parts 1 and 2.
    So basic info, then scroll down for more detailed info about cell chemistries and charts and tables and whatnot.
    In date order, as far as I can remember: Mag 4D LED, LL P14, Fenix LD20 R4, 47s Preon 2 R5 red, 47s Quark Mini AA S2, Fenix TK35 XM-L T6, 4Sevens ReVO SS S2, Maha MH-C808M, Maha MH-C9000, 47s Single Bay Li-ion charger, Zebralight SC600 XM-L U2, Fenix TK70, iCharger 206B, Sunwayman D40A...

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    Default Re: New section added 12/26/11: Li Ion beginner primer

    Quote Originally Posted by Joe Talmadge View Post
    Okay, 12/27/11, I added some words to address battery chemistries and the use of a DMM. Notes as to where those sections are, are at the top of the primer. Thanks again for the help in making this better.
    Hi Joe, You mention DMM as "DMM (Digital Multimeter)" Why not "LiCo (LithiumCobalt)" or "LiFePo (Lithium Iron Phosphate)" I've been out of high school almost 50 years I guess that makes me old fashioned but, why is something this simple have to be so difficult. I don't think searching a periodic table is simpler than adding a few words as a definition. Once again I applaud (?) your caution warnings.
    Fred R. Elias Jr. N162E
    1-586-755-1245 24/7
    fre@felias.com

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    Default Re: New section added 12/26/11: Li Ion beginner primer

    I'm confused by the statement:
    "Safe chemistry, so is not available with a protection circuit. But that means the consumer must guard against overcharge and overdischarge themselves."

    If it is safe, then why do I need to guard? I wouldn't be telling someone it is safe if there is still a risk of explosion/fire.

    I thought all lithium-ion batteries are the same when it comes to over dis/charge safety risks.

    I've also been curious how dangerous a lithium-ion battery is when overdischarged. I would assume there isn't enough energy from a discharged battery to be very dangerous, but maybe it doesn't take much.
    Wish: 1) Super low beacon; easy find flashlight. 2) Low voltage indicator, so not stranded without light. 3) Simple, one handed control ring mode changer (magnetic control ring). 4) Flood beam for walking/tasks. 5) Pocket carry. 6) LiFePO4.


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    Default Re: New section added 12/26/11: Li Ion beginner primer

    Quote Originally Posted by snakyjake View Post
    I'm confused by the statement:
    "Safe chemistry, so is not available with a protection circuit. But that means the consumer must guard against overcharge and overdischarge themselves."

    If it is safe, then why do I need to guard? I wouldn't be telling someone it is safe if there is still a risk of explosion/fire.

    I thought all lithium-ion batteries are the same when it comes to over dis/charge safety risks.

    I've also been curious how dangerous a lithium-ion battery is when overdischarged. I would assume there isn't enough energy from a discharged battery to be very dangerous, but maybe it doesn't take much.
    The OP is correct. Chemistries such as LiFePo4 are relatively safe. You need to guard against over-charging or over-discharging - not because of hazardousness of the cell - but because either of those states can reduce the life of the cell.
    So the purpose of guarding against over-charging/discharging is not for the protection of the user, but for the protection of the life of the cell in those cases.
    Not all lithium-ion cells are the same in terms of safety.

    With LiCoO2 for instance, the danger involved in over-discharging is not necessarily immediately when the cell is discharged. The danger is because copper shunts can begin to form internally, shorting the cell out. These shunts may not short immediately as they may take time to form. But they could short at an unknown time in the future, perhaps when the cell is fully charged and inside a piece of equipment, or when it is on the charger, etc.
    Last edited by samgab; 12-28-2011 at 01:48 AM.
    In date order, as far as I can remember: Mag 4D LED, LL P14, Fenix LD20 R4, 47s Preon 2 R5 red, 47s Quark Mini AA S2, Fenix TK35 XM-L T6, 4Sevens ReVO SS S2, Maha MH-C808M, Maha MH-C9000, 47s Single Bay Li-ion charger, Zebralight SC600 XM-L U2, Fenix TK70, iCharger 206B, Sunwayman D40A...

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    Default Re: New section added 12/26/11: Li Ion beginner primer

    I'd also mention:

    1) LiNiCoO2.

    2) Anti-expolsion vent/PTC module provides an added layer of protection against gas build-up in addition to the PTC thermal protection. Unlike regular vents used by most Li-Ion cells, these modules actually stop the action by separating the electrodes inside the battery when the pressure reaches a preset threshold. The vent disc will open and release the gas plus stopping the cell from further chemical reaction.

    3) Heat Resistance Layer (HRL) technology that forms an insulating metal oxide layer between the positive and negative electrodes. The layer prevents the battery from overheating even if a short circuit occurs.
    Wish: 1) Super low beacon; easy find flashlight. 2) Low voltage indicator, so not stranded without light. 3) Simple, one handed control ring mode changer (magnetic control ring). 4) Flood beam for walking/tasks. 5) Pocket carry. 6) LiFePO4.


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    Default Re: New section added 12/26/11: Li Ion beginner primer

    Just a note on "safe" chemistry Li-Ion cells. There are no "safe" chemistry Li-Ion cells. There are "safer" chemistry cells, such as LiMn and LiFe, with LiFe being the "safer" of the two. The difference between these two chemistries and LiCo cells is that they are somewhat more tolerant to abuse. They require more extreme conditions before a "venting with flame" incident can occur. That said, there is at least one thread here on the Forums showing the charred remains of a LiFe disaster. The light was literally "toast" after installing discharged cells along with fully charged cells in series.

    The "safe chemistry" slogan, I think is more of a marketing tactic than anything. All Li-Ion cells contain volatile solvents in their manufacture. It is these solvents that under the right conditions, will ignite and result in a "venting with flame" incident. There is more than one way this can be triggered, but the result is the same.

    As far as the state of charge of a LiCo cell (I believe this applies to the other chemistries, as well, but not sure), if shunts have formed within the cell and there is enough power left to heat things up enough to ignite the solvent, then you have a potential problem, even with a basically, discharged cell.

    Oxygen formation is one of the byproducts of a damaged Li-Ion cell, so heat (whether caused by internal short circuit, attempting to charge a damaged cell, discharging at a high rate, metallic lithium that has formed on the electrodes and begins to oxidize, or......), a volatile solvent, along with oxygen, is what creates the potential hazard in all Li-Ion cells.

    Dave

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    Default Re: New section added 12/27/11: Li Ion beginner primer

    You know, I'd toyed with the idea of using the term "safer chemistry", and avoiding the word "safe" anywhere. Perhaps I'll do that. In the advanced section, I'll talk a bit more about the possible failure modes, including the discussions we've had in this thread. It won't be until at least Thursday before I get to the revision, but I think we're circling in on the right information and the right format

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    Default Re: New section added 12/27/11: Li Ion beginner primer

    I'm trying to figure out capacity vs. safety:
    1) How much capacity I lose by going safer?
    2) How much safety I'm gaining?

    In this thread I'm hoping #2 can be answered.
    Is there a safety margin defined?
    What kind and how much more "tolerance" and "abuse" can they take? Are we talking the type of abuse from using construction tools? Or being left on the charger? Do our normal use of flashlights cause battery abuse?

    45/70 mentioned "somewhat more tolerant to abuse". But also says "require more extreme conditions..." I'm having troubles understanding "somewhat" meaning small, and "extreme" meaning a lot.

    When I read Battery Junction's (BJ) safety description of IMR, the precautions looked identical to what I've read regarding LCO on the forum. BJ even said this about LCO: "Protected lithium rechargeable batteries are very safe..."

    So I'm starting to draw the conclusion, for LED flashlights: All lithium-ion chemistries have the same risk. One battery chemistry is not safer than another. The "safer" definition regards to a different use, not LED flashlights. But I'm not sure if there are extreme high drain flashlights that people are using on the forum. Not sure what defines high drain either.

    So since I'm not using high drain LED flashlights, the "safer" chemistry doesn't apply?

    Jake

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    Default Re: New section added 12/27/11: Li Ion beginner primer

    Quote Originally Posted by snakyjake View Post
    45/70 mentioned "somewhat more tolerant to abuse". But also says "require more extreme conditions..." I'm having troubles understanding "somewhat" meaning small, and "extreme" meaning a lot.
    Hi Jake. I think you took what I said out of context.

    The attributes of both LiMn and LiFe cells are more forgiving than those of LiCo or LiPo cells. The conditions I mentioned in my previous post under which a "vent with flame" incident is likely to occur, require more extreme conditions with LiMn and LiFe cells.

    For example, the temperature at which oxygen formation occurs, is higher with these cells, as compared to LiCo/LiPo. This means that under abusive conditions it will take longer and/or the current level will be required to be higher, for an incident to occur. Thus these two chemistries are in fact somewhat safer. However, if the limits are pushed to the max, a vent with flame incident can still occur. So again, there really are no "safe" chemistry Li-Ion cells, just somewhat safer.

    Protection circuits which have been added to manufacturer's LiCo Li-Ion cells by third parties, are a matter for another discussion. The question here is, will they even work. Was the protection circuit added to the cell designed for your specific application? Does your application typically draw 20ma of current, or 5A? Protection circuits added to cells can't do both, at least not with any certainty. This is why the common comparison of protection circuits used in laptops, and those added to LiCo cells for use in a wide variety of our lights, is non sequitur. The PCBs added to LiCo cells are a "catch all" and cannot cover every possible usage scenario. They are installed as a last resort to help prevent an "incident", and should not be relied upon.

    Dave

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    Default Re: New section added 12/27/11: Li Ion beginner primer

    Hi Dave, thanks for the reply. I'm still trying to find the "context" in an internet forum conversation, and respect the many posts you've made on the subject.

    I'd like to understand more about the "abusive conditions" context. Is that like construction power tools, or constantly over-discharging our single bulb lights?

    This brings up the next question...

    The "abuse" I commonly hear about is over-discharging, unbalanced mutli-cell, over-charging. Over-discharging is my #1 concern, as it takes the most user effort to monitor (and I never do it, and rely on protection circuit). I use singe cell lights and high quality charger to mitigate the other risks.

    So does "safer" mean chemical abuse (i.e. over-discharging)? Or only physical (construction power tools) abuse?

    Jake

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    Default worried about 18650's

    So being new to this world of high lumin flashlights, and spending the last few weekends reading stuff in these forums [great info. by the way] my head feels like it is ready to go the way of the exploding batteries I keep reading about.
    Right now I am running CR123a primary batteries in both my Fenix TK35 and TK21. The first set of primay's in my TK35 were tossed as soon as I lost my turbo level of light. That was my signal that they were getting weaker. Taking no chance, and having no single cell light, I got rid of them and put in a new set.
    I am now thinking of switching to AW 18650's knowing what future costs of primay's will add up to.
    Here is my question, or one of many to come, and I hope it has not been covered before as I did have a quick look.
    Why are laptops not exploding all over the world. I mean alot of laptops. Most people I know have them plugged in day and night with no event of venting. Or they run them down until they are empty before charging with no need to put a DMM on them[or no way of doing so] These are the same laptop units that I keep reading about in these forums, where people are harvesting some of their 18650's from.
    I will take precautions. I will buy what Fenix is offering right now, the Ultrafire WF 139 and later get a Pila. The Ultrafire charger is coming with AW 18650 3100 mAh batteries. I have a DMM which I will use, don't need the ZTS tester for these I believe?? I will pull the cells as soon as the light is green to cover my rear until the Pila is here.
    I trust this is somewhat of a safe approach.
    But why, oh why, are laptops not exploding?
    Thanks guys.

  16. #76
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    Default Re: worried about 18650's

    A few thoughts from someone who is admittedly not an electronics expert:

    1) The battery packs aren't truly being run down. The software/firmware on the OS and in the battery pack don't let you fully discharge the pack. There is a buffer. Take a bare, unprotected cell and put it in an LED light with flat regulation and no overdischarge protection and let her rip. Different story.

    2) The dangers of lithium cobalt cells are very well documented on CPF, and that may make people fearful. You shouldn't be. Prudence is key. If you are ready to drop primaries and go 18650, here are my suggestions:

    -buy cells from a trusted labeler (you already know who those are)

    -use a quality charger (Pila IBC, cottonpickers, or hobby charger)

    -don't run your cells down all the way

    -don't store them in your furnace room or in a hot car

    -when the cell gets weak/doesn't charge, recycle it

    We have lots of members who use these cells without issue, and a few who do encounter problems. While there are no guarantees (in life or with batteries), doing the above will minimize the chances of trouble.

    Again, I am not an expert in this area, and the above suggestions are just what I have gleaned from speaking with those who do know their stuff in and out. I am sure others will chime in.

    Good luck!
    "...and the diode multiplied and grew in brightness. And God saw that it was good."

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    Default Re: worried about 18650's

    IMHO

    I found through searching CPF that some 18650 have the most reliable protection for cutoff at 20% capacity.
    -they actually cut off as they should. other batteries tested in that particular round did NOT cut off depletion.

    so even with protected batteries there is a lot of variance on the reliability of the protection circuit itself.

    dig up some CPF articles and shootouts, make an informed decision. and YES get and use a nice little voltmeter to monitor all
    your rechargables.

  18. #78
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    Default Re: worried about 18650's

    Hello Loquutis79,

    Welcome to CPF.

    There are at least three parts to laptop power safety.

    The first is that they use quality cells.

    Next the laptop has thermal monitoring added to the battery pack.

    Third is the power management circuits that set charge rates and maximum and minimum voltage. Some even have a cycle count. The design engineers know that a battery is only good for so many cycles, so if you count the number of cycles you can eliminate problems by simply shutting the pack off after that many cycles have passed.

    Let's compare this set up to using a single cell in a flashlight.

    A quality cell is usually not the most inexpensive cell that can be found. Many are more concerned with price than with quality.

    In laptop use, when the temperature goes up a fan kicks on to cool things down. Most flashlights just get hotter and hotter.

    In laptop use the charger is built into the unit. The charge algorithm is designed to maximize the cycle life of the battery pack. If unusual high current draw is observed (a short), the monitoring circuit shuts things down. If cycle counting is used, the battery pack is shut down when it is close to its expected cycle life.

    In flashlight use you pick a charger. Once again many are more concerned with price than quality, and a low quality charger may not take good care of the cell. With some chargers you also have the option to choose the charge rate. The charge rate you choose may not be the best charge rate for the cell. In a flashlight you may end up over discharging the cell. All of these variables can subject the cell to abuse, and that can lead to problems. The battery pack in the laptop makes an effort to control all of these variables so that it won't catch on fire.

    In addition, many people feel that as long as a cell can store any capacity at all, it is still good. This compounds the danger because as a Li-Ion cell ages the electrolyte oxidizes and becomes more unstable. Continuing to use a cell that is not "healthy," amplifies the possibility of having a "rapid venting accompanied with flame" event.

    When a Li-Ion cell has dropped below 80% of its initial capacity, it is time to recycle it.

    These are just a few of the differences between laptop use and flashlight use. Another thing that comes to mind is physical abuse. Most people take extreme care not to drop their laptop. The same can't be said for flashlight use.

    In an effort to bring some degree of safety to flashlight use, some offer a protection circuit that has been attached to the cell. This protection circuit protects against GROSS over charge and over discharge, and usually has a maximum current limit. It offers some protection, but it is not as good as the management circuit built into laptops.

    The bottom line is that laptops don't explode because they have a power management circuit that takes good care of the battery pack, and they use quality cells. If you take the same precautions with flashlight use, the cells used with flashlights will not explode either. (As a footnote, these cells don't explode, they rapidly vent, sometimes with flames...)

    Tom
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    Most batteries don't die - they are tortured to near death, then murdered...

  19. #79
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    Default Re: worried about 18650's

    Quote Originally Posted by loquutis79 View Post
    Why are laptops not exploding all over the world. I mean alot of laptops......

    But why, oh why, are laptops not exploding?
    Hi loquutis and welcome to CPF!

    I see reference to this quite often. What most people don't realize is that the protection circuitry built in to laptops and other consumer devices that utilize various types of Li-Ion battery packs, are designed for that specific device and it's associated current demands.

    The best we flashaholics can do to simulate this type of protection, is purchase cells with a protection PCB that has been added onto the bottom of the cell by a third party, or only buy lights that have their own built in protection circuitry. The later, which is really the prefered method, in all cases I'm aware of, is only effective with single cell lights, however.

    As for protection circuits added to individual cells by third parties, these circuits by necessity, have to cover a wide range of potential operating conditions. Will the cell be used in a light that draws 20mA, or one that draws 5A? The protection circuit added to the cell can't really do both effectively, so a compromise has to be made.

    Also, there is the quality of the components used and the construction of the protection circuits. Some are made with precision and from quality components, others, maybe not.

    Li-Ion cell manufacturers do not supply Li-Ion cells at the consumer level, nor do they manufacture protection circuits. Protection circuitry is normally provided by the device, or battery pack maker, and proof of such is required before a Li-Ion cell manufacturer will provide them with cells. This is for liability reasons. So, protection circuits that have been added to individual cells is one point where a compromise has been made concerning the safety level of our lights.

    In many cases (more than likely most), the individual, or "loose" as they are called, Li-Ion cells that we purchase for use in our lights are bought up as "factory seconds" that for one reason or another were deemed not useable for the manufacturing of battery packs by the manufacturer of the cells.

    The last I was aware of, there is a worldwide shortage of, in particular, 18650 size Li-Ion cells, for use in the making of battery packs for laptops and other consumer products. If you search the net, you will find many trading companies, mostly in China, offering name brand Japanese and Korean 18650 cells in large quantities (eg. 1000+) from companies such as Sanyo, Samsung, Panasonic, LG, and others. With this worldwide shortage of 18650 cells, you have to ask yourself, where did these cells come from? And, who do you suppose buys them?

    Many of the Chinese Li-Ion cell distributors (not manufacturers) actually relabel recycled cells, as well as those obtained from battery packs that were involved in a "recall" for whatever reason. Most of these companies go by some sort of "Fire" brand name, such as "CrapiFire", or BangiFire, or some such other nonsense name that plays upon the U.S. based SureFire company name. At any rate, here we have yet another drop in the potential safety level of the cells we obtain. Some might be just fine, but others.....?

    The best we can do is buy cells from a reputable source. Due to the higher cost of quality cells, and better components used in the protection circuits (if added), cells from these distributors are going to carry a higher price. Top tier cells (whether "seconds", or not) no doubt cost more than lower quality cells, or those obtained from recalled or recycled battery packs, so the distributor/dealer has no choice but to pass this additional cost on to the buyer.

    So anyway, you can't really compare the cells and associated protection circuitry used in our hobby, to those used in laptops, or any other consumer device. There are just too many potential variables for a comparison.

    EDIT: I see that in the time it took me to write this up, Tom posted. Oh well, the more the merrier. :-)

    Dave
    Last edited by 45/70; 01-22-2012 at 03:42 PM. Reason: added edit

  20. #80
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    Default Re: worried about 18650's

    Ok, I will buy that. I will still make sure I take all the precautions that I have read here.

    My other question, and I hope it is ok to ask in the same tread is, if I order the Pila IBC 4 Stage which I intend to, will it take AW 18650 3100mAh batteries? Is the diameter and length of this cell going to fit and charge properly? I have a local supply of AW 18650 3100mAh and as they are touted to be one of the best I would like to stick with these.

    And what will give me a brighter, longer lasting light in my Fenix TK35 and TK21, primay's or the 18650's?

  21. #81

    Default Re: worried about 18650's

    tagged for reference

  22. #82
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    Default Re: worried about 18650's

    Just wondering what "tagged for referance" means.
    Did I post something wrong?

  23. #83

    Default Re: worried about 18650's

    No you Didn't
    I wanted to follow this thread so i put a short response on it
    But I SHOULD have just used tools to subscribe to it

  24. #84

    Default Re: worried about 18650's

    Great info guys.

    So when you guys say not to "run it down" does that mean leave your light on until it dies, leaving your battery sitting on your shelf forever, or in your flashlight?

    Is it safe to leave it in a protected charger? Say I'm using one for a month or so while I have another 18650 waiting in the charger to switch out. Is this safe?

    Should I always discharge after use?

    Thanks!

  25. #85
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    Default Re: worried about 18650's

    Quote Originally Posted by c.joe View Post
    So when you guys say not to "run it down" does that mean leave your light on until it dies, leaving your battery sitting on your shelf forever, or in your flashlight?

    Is it safe to leave it in a protected charger? Say I'm using one for a month or so while I have another 18650 waiting in the charger to switch out. Is this safe?
    For a RCR123, don't let it go below 2.75v. Don't overcharge it above 4.20v. This might be the same for 18650 if using the same chemistry.

    Should I always discharge after use?
    I don't want to charge the battery too many times, and lessen the life. I also keep my batteries stored fully charged.

    I rely 100% on the protection circuit and charger. But others don't trust a circuit. I've never read any tests done on protected circuits, so am unsure how much to trust it. I might be asking for trouble at some point when my cells get old.

    Jake

  26. #86

    Default Re: worried about 18650's

    ""So when you guys say not to "run it down" does that mean leave your light on until it dies, leaving your battery sitting on your shelf forever, or in your flashlight?

    Is it safe to leave it in a protected charger? Say I'm using one for a month or so while I have another 18650 waiting in the charger to switch out. Is this safe?""

    If your question is pertaining to protected cells... the circuit(s) will normally kick-in...around 3 for an RCR and 3.6 for a 18650. Do not leave a cell sitting in the Pila (plugged-in) until you need it. They should be removed reasonably soon after the charge light turns green.

  27. #87

    Default Re: worried about 18650's

    I too was once worried about 18650's that i was using in a rop low maglite, The only thing i can recommend is aw imr 18650's, they dont have protection circuits because they are quality cells that use safe chemistry, yes there more expensive than firexxx branded cells but in my opinion id rather have peace of mind than a possible pipe bomb in my hand.

    Vinny.

  28. #88
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    Default Re: worried about 18650's

    I think that reading stories of these going bad has stopped me from jumping on the 18650 bandwagon, but i've been researching what I can about them and seeing what would be the safest setup I can use. Another question about 18650 charging ive really have been able to find is if its safe to use the pila charger and put into something that could contain a meltdown like a metal tool box or something.

  29. #89
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    Default Re: worried about 18650's

    Quote Originally Posted by vinny View Post
    The only thing i can recommend is aw imr 18650's, they dont have protection circuits because they are quality cells that use safe chemistry...
    IMR is not "safe" chemistry and can still explode. Protected lithium-ion is the safest lithium-ion battery for flashlight use.

    The safe rechargeable chemistry for flashlights is NiMH.
    Last edited by snakyjake; 01-27-2012 at 07:32 AM.
    Wish: 1) Super low beacon; easy find flashlight. 2) Low voltage indicator, so not stranded without light. 3) Simple, one handed control ring mode changer (magnetic control ring). 4) Flood beam for walking/tasks. 5) Pocket carry. 6) LiFePO4.


  30. #90

    Default Re: worried about 18650's

    Quote Originally Posted by snakyjake View Post
    I also keep my batteries stored fully charged.
    They'll degrade fast if you leave them like that.

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