# 18650 - Are protected batteries ALWAYS better?



## Dave Dunn (Jun 6, 2016)

For use in single cell applications,are protected batteries ALWAYS better,or are there some situations where unprotected batteries might be more practical? Do protected batteries have limitations regarding charging and discharging which might hinder field work,trickle charging etc?


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## Strintguy (Jun 6, 2016)

Hi Dave, I think your question has been asked and answered in a myriad of ways, but always great to hear from our educated and enlightened (ha!) members. I'm neither of those but I can get things started. 
Short answer is "no" protected are not always better. They have a protection circuit which is another thing that can go wrong. They may trip out and leave you in the dark. Protected are longer and often wider and can present a fitment issue.
My take on it is that you should use only high quality batteries and keep track of their usage and charge them on a high-quality charger.


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## Dave Dunn (Jun 6, 2016)

I know,with days of reading 10 pages per question for 10 hours for 10 days I might get close to understanding and still not have an answer.


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## Dave Dunn (Jun 6, 2016)

Basically I'm worried that when I'm out in the bush,with no mains power and trying to charge batteries with solar panels or the usb charger that plugs into my car cigarette lighter I'd be better off with unprotected batteries,but I tried to form the question so that the answers would be more useful to the general newbie community for later reference


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## ven (Jun 6, 2016)

Pros and cons of either protected or not. The pcb is for over and under discharging so for example it may trip at 2.5v and 4.25v. Most single cell(multi to) lights these days have some kind of safety cut off or warning. Be it flashing light, loss of higher modes etc. To get a cell down to 3v which is above manufacturers minimum V take some doing tbh...... 

Many prefer protected cells in multi cell lights that may run in series. Depending on the user their choice could be either type of cell. I prefer unprotected in single and multi cell lights, higher drain cells basically. 

Regardless of protected or not, practice should be the same which is not deep discharging the cells regularly . This can shorter the life of the cell/s over time. Learn the light, check the V at set times to get an idea of the voltage used between charges . For example you may use medium for 5hrs over a week. The voltage may be 3.6v and so you know you can charge the cell up weekly. Or you may simply prefer to top it up after each use , or every other day......

Protected are a few mm longer , some lights they can be a tight fit! Same with some carriers ,but of a squeeze to get the 70mm cells in. The unprotected may be 66mm long and fit a lot easier and may sway your choice. The savings per cell of unprotected might too.......Protected also have a slight drain due to the pcb and it's also something else to fail for some people ,who need to limit failures due to their actual use.

So no IMO protected are not better, depending on the application they have their advantages but that's it for me. If the user is dependable on the pcb to tell them the cell is low by tripping, then the chemistry is wrong for them .

Just as important as good cells from reputable shop/seller is the charger! One that works to spec and terminates to spec without trickle charging .

There really is no art or requirement for a degree , just a read up , an understanding , common sense and ideally a tool to measure the voltage away from the charger to aid fault finding and simply to have another form of measuring the V. Lot of good chargers have a V readout, might be enough for some. 

Limitations wise, too much amp can trip the pcb (2 ways of looking at it as tripping due to too much current is also a good thing). So some lights protected cells are not a good option. Also if a strip down the side ,its susceptible to shorting if damaged .

Regarding choice of which to go for would depend on what light ,what type of use . From this I would make a decision on which type of cell.

Thats a a brief take on it from me, not saying I am right, just the way I look at it. 

Typed on an iPhone so god knows what *beep* it's changed !!


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## fivemega (Jun 6, 2016)

Dave Dunn said:


> are there some situations where unprotected batteries might be more practical? Do protected batteries have limitations regarding charging and discharging which might hinder field work,trickle charging etc?


*If current draw is more than what protected cell can provide, unprotected or IMR cells will serve better but if that current draw is within safe operation, using unprotected cell is unnecessary.*


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## Newlumen (Jun 6, 2016)

I don't know much about the cells.. I always go with unprotected battery. Since most of my light are modified. I can also use unprotected cells in stock light too if I need it..


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## oKtosiTe (Jun 7, 2016)

fivemega said:


> *If current draw is more than what protected cell can provide, unprotected or IMR cells will serve better but if that current draw is within safe operation, using unprotected cell is unnecessary.*



Unless, as with the Zebralight SC600-III, protected cells simply will not fit.
I'd say it highly depends on the light and charger used and the application.
Generally speaking I would recommend protected cells for lights that support them, or following the manufacturer's recommendations.


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## Dr. Mario (Jun 7, 2016)

As for protected cells, it depends on several factors, such as battery low voltage cutoff (most DIY LED flashlight drivers already have Li-ion battery protection in form of software - they shut down at around 2.8 Volts - some stock LED flashlights also have similar firmware in the SOIC-8 packaged microcontrollers - be it ATTiny or PIC16) and overcharge cut-off, that's where decent charger comes in - I have Foursevens single bay smart charger for almost three years, no problem with it so far.

You can put in protected call in some flashlight, providing they fit in the battery body (tube) - the driver won't care about up to 200 millivolts drop across circuit breaker MOSFET. One more problem, is that they add up to 3 mm in length due to the protective plastic cap at bottom of Li-ion battery containing protection PCB. I usually run unprotected Li-ion batteries anyhow as they don't go over 3 Amps in my flashlights (although one of my recent Nichia NVSW219CT neutral white flashlight might hit 3 - 4 Amps when in direct-drive mode on a freshly charged 3.3 Volts Lithium Iron Phosphate cell).


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## recDNA (Jun 7, 2016)

Wow. I didn't know LiFePO cells provide high current draw like that.


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## Dr. Mario (Jun 7, 2016)

That depends on state of charge, of course; the higher voltage, the higher the current. It also depends on Vf. Cree LEDs suck in LiFePO4 cell compatible flashlight due to their generally higher Vf. So, Nichia NVSW219CT LED is definitely the LED to go with for 3.3 Volts batteries.


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## StorminMatt (Jun 8, 2016)

recDNA said:


> Wow. I didn't know LiFePO cells provide high current draw like that.



A123 Systems LiFePO4 18650s can provide a continuous 33A. Admittedly, though, with only 1100mAH of capacity, they won't do this for long.

As for the original question of protected vs unprotected batteries, I myself have never used protected batteries. Even in lights with series cells. Unprotected batteries are cheaper, smaller (especially shorter), and produce a higher voltage. People worry about safety. But if you use quality cells, quality chargers, store them in plastic cases, and use them in single cell lights with built-in overdischarge protection, there is absolutely NO safety disadvantage to using unprotected cells. In lights without overdischarge protection, safe use of unprotected cells is mainly a matter of knowing how long your light will run on a full charge and keeping it charged. Also, recognizing when your light starts to dim is VERY helpful in knowing when it is time to change batteries. With multi-cell lights, it's all about knowing your runtime. Low battery warnings can also help, especially if you use good quality cells that track voltage evenly from one cell to another.


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## TinderBox (UK) (Jun 8, 2016)

Just spotted this on BangGood, this is the HKJ recomended single slot charger.* "I have no affiliation with this seller"

LiitoKala Lii-100 0.5A/1A Li-ion Ni-MH USB Battery Charge*

$3.80 48% OFF

http://www.banggood.com/LiitoKala-L...d=QLKeQnxox6&emst=QLKeQnxox6_24818_1867134_49


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## Dr. Mario (Jun 8, 2016)

StorminMatt said:


> A123 Systems LiFePO4 18650s can provide a continuous 33A. Admittedly, though, with only 1100mAH of capacity, they won't do this for long.



Correct. However, 1.1 Amps / hour is good enough for my flashlight usage as I have two of A123 LiFePO4 cells, and there are multiple modes I can use (as far as ToyKeeper Bistro firmware in the hybrid FET - 7135 driver is concerned). It won't do on old school Halogen flashlight, however, even though it's a powerful cell.


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## StorminMatt (Jun 9, 2016)

Dr. Mario said:


> It won't do on old school Halogen flashlight, however, even though it's a powerful cell.



I would think that, with its dead-flat discharge curve, LiFePO4 would be IDEAL for incandescent flashlights.


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## Dr. Mario (Jun 9, 2016)

It depends on the incandescent bulbs, of course. Some are quite puny, others just rape the batteries. However, I agree that LiFePO4 cell have rather flat discharge curve - I have noticed that when I played with my brand new DIY Nichia 219C LED flashlight (turbo mode has current of 1.4 Amps which is enough to get flashlight rather warm after ten minutes - it barely taper off in brightness).


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## stephenk (Jun 9, 2016)

To be honest, if someone is asking the protected vs unprotected question, then they should probably use protected.


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## Dr. Mario (Jun 9, 2016)

Unless you use single cell in a powerful flashlight containing a microcontroller chip which has low voltage lockout, there's little point in using protected cell. I routinely run unprotected cells in my single cell flashlights I assembled. On the other hand, the protected cell do have its merits such as usage in the solar charger.


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## Gauss163 (Jun 9, 2016)

StorminMatt said:


> I would think that, with its dead-flat discharge curve, LiFePO4 would be IDEAL for incandescent flashlights.



Which has the disadvantage that you get almost no warning when the voltage abruptly drops from full to empty (same problem for cells with internal buck/boost converters). Cells with flat discharge curves require special fuel gauges that attempt to workaround this.


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## space-cowboy (Jun 9, 2016)

Protected batteries should be used always and whenever possible.

Big battery manufacturers are very clear about this.
Unprotected cells should not be used in any application without proper protection.

What some posters here did not mention is extremely important, and it is called SAFETY.
Protection is not there (especially on 18650, 26650, 14500....) for overcharge or over-discharge purpose only.
Main reason that should be always on the first place is Safety.

Short circuit is dangerous as hell, and should be prevented at all costs when working with li-ion.
That's why we are using Protected batteries.

Sony is already contacting sellers and asking them to stop selling unprotected Sony VTC batteries to vapers (obviously flashlight community will be "hurt" by this as well).
Next will be LG.

Everyone should watch this video and learn something from it.

https://youtu.be/xS8LsPv1_uM

Now, go ahead and put your unprotected cell in your pocket together with car keys and some metal coins. 

Of course - don't do it 

High quality protected 18650 battery is able to handle up to 10-12 Ams.
How many Amps one flashlight needs, 20A ?
I do not think so.


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## recDNA (Jun 9, 2016)

With so many users now proclaiming unprotected batteries are not only as good as protected batteries but somehow better or even safer it is refreshing to read a post like yours.

For all but the most experienced and safety conscious users I agree protected cells are best.


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## SG Hall (Jun 9, 2016)

To get back to the OP title, the answer still has to be no. Even a flashlight novice such as me knows the dangers of ICR chemistry over IMR, the dangers of shorting an ICR with no protection, and of over discharge. They are clearly not safer without the protection cell and this has to be factored in. But the answer is still no. In a high drain device an unprotected cell is better unless we bought it to look at. 🤔

We go hunting, ride motorbikes and play sport and we ( most of us anyway!) avert risk where possible and still participate. And we use unprotected cells in our quality high drain lights to get extra performance. It is no different in my view.


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## space-cowboy (Jun 9, 2016)

SG Hall said:


> To get back to the OP title, the answer still has to be no. Even a flashlight novice such as me knows the dangers of ICR chemistry over IMR, the dangers of shorting an ICR with no protection, and of over discharge. They are clearly not safer without the protection cell and this has to be factored in. But the answer is still no. In a high drain device an unprotected cell is better unless we bought it to look at. 🤔
> 
> We go hunting, ride motorbikes and play sport and we ( most of us anyway!) avert risk where possible and still participate. And we use unprotected cells in our quality high drain lights to get extra performance. It is no different in my view.



What is difference: unprotected ICR vs unprotected IMR ?

Please explain


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## Dr. Mario (Jun 10, 2016)

ICR = Lithium Cobalt Oxide cell and IMR = Lithium Magnesium Dioxide cell. IMR cells have higher runaway temperature point than ICR cells - the reason why ICR cells run away rapidly at 90 Celsius (194 Fahrenheit) is because of Cobalt Oxide, and Cobalt easily let go of Oxygen at that temperature (since it has incredibly weak Oxygen bond), and all that adds Oxygen to the fuel (in this case, incredibly flammable Ester-based - or any Ether compounds - electrolytes which has lower flash point than Gasoline - 180 to 250 Fahrenheit is enough to ignite it). Magnesium has somewhat better grip at Oxygen so the IMR battery is unlikely to run away unless it gets past 240 - 270 Celsius (464 to 518 Fahrenheit), which means it / they won't vent with flame since Magnesium wouldn't let go of Oxygen if the venting battery didn't hit 460 - 520 Fahrenheit. IMR cells are also internally constructed to take a lot of electrical abuses (although not as good as Lithium Iron Phosphate cells), making it attractive for usage in the vapers and powerful flashlights.


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## HKJ (Jun 10, 2016)

Dr. Mario said:


> ICR cells run away rapidly at 90 Celsius (194 Fahrenheit)



That is way to low, it is in the 150C (Venting) to 210C (Thermal runaway) range.
http://pubs.rsc.org/en/content/articlehtml/2013/ra/c3ra45748f

If the runaway was at 90C I would have seen many runaway during my testing, but I have never seen one.


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## StorminMatt (Jun 10, 2016)

Also, keep in mind that there are not a whole lot of pure ICR cells sold anymore. Most high capacity cells these days are hybrid IMR/INR cells, which are significantly safer than pure ICR cells.


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## Dr. Mario (Jun 10, 2016)

HKJ said:


> That is way to low, it is in the 150C (Venting) to 210C (Thermal runaway) range.
> http://pubs.rsc.org/en/content/articlehtml/2013/ra/c3ra45748f
> 
> If the runaway was at 90C I would have seen many runaway during my testing, but I have never seen one.



Good point, I stand corrected. Older ones will, though (which was why Sony had to up their safety research department a few decades ago).

StorminMatt - that's a good thing pure ICR cells are going the way of dinosaurs because it's somewhat easy to mishandle those cells, and I'd rather using safer variant of Lithium-ion cells.


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## recDNA (Jun 10, 2016)

Ya, unfortunately except for old cells you cannot buy pure IMR chemistry cells assuming you ever could. Most cells today are hybrid, maybe all. This means we have no real idea at what temperature they will burst into flame. There are now protected cells that give us 10 amps without tripping. That is enough for a flashlight. 

Zebralight now insists on unprotected cells. I'll stick with the older models.


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## StorminMatt (Jun 10, 2016)

recDNA said:


> Zebralight now insists on unprotected cells. I'll stick with the older models.



Then again, how is a protection circuit mounted on a battery REALLY better than one in a light? In fact, I would rather have protection in a light than on a battery (where it will get banged around, dropped, and where it often has a strip down the side that can potentially be a dead short). I just don't see how an onboard protection circuit is BETTER than using good cells, using good chargers, and storing batteries in plastic cases so they can't short.


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## recDNA (Jun 10, 2016)

Better to have both. I like protected batteries for charging too


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## Dr. Mario (Jun 11, 2016)

I just go with unprotected cells, less headaches in term of strange behaviors in protection board, and fitment. I do follow very strict battery handling rules, so I ought be good to go, with the unprotected cells.

For the newbies, I'd recommend to go with protected cells, even the LiFePO4 cells, just so they don't cause damage when one makes a mistake.


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## magellan (Jun 11, 2016)

StorminMatt said:


> A123 Systems LiFePO4 18650s can provide a continuous 33A. Admittedly, though, with only 1100mAH of capacity, they won't do this for long.
> 
> As for the original question of protected vs unprotected batteries, I myself have never used protected batteries. Even in lights with series cells. Unprotected batteries are cheaper, smaller (especially shorter), and produce a higher voltage. People worry about safety. But if you use quality cells, quality chargers, store them in plastic cases, and use them in single cell lights with built-in overdischarge protection, there is absolutely NO safety disadvantage to using unprotected cells. In lights without overdischarge protection, safe use of unprotected cells is mainly a matter of knowing how long your light will run on a full charge and keeping it charged. Also, recognizing when your light starts to dim is VERY helpful in knowing when it is time to change batteries. With multi-cell lights, it's all about knowing your runtime. Low battery warnings can also help, especially if you use good quality cells that track voltage evenly from one cell to another.



Great summary of the issues from you and Ven. That's kinda how I look at although I do have maybe 20% of my 40 or so 18650 batteries in protected versions with various brands.


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## recDNA (Jun 12, 2016)

I have both but I prefer to use protected batteries if they fit. I'm always torn between unattended charging on a concrete garage floor and me watching charging on a porcelain plate on a wooden coffee table. I charge indoors where I can watch but find it stressful. I prefer to use primaries when possible because I hate charging so much. Never had a problem charging. Just aware.


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## StorminMatt (Jun 13, 2016)

recDNA said:


> I have both but I prefer to use protected batteries if they fit. I'm always torn between unattended charging on a concrete garage floor and me watching charging on a porcelain plate on a wooden coffee table. I charge indoors where I can watch but find it stressful. I prefer to use primaries when possible because I hate charging so much. Never had a problem charging. Just aware.



Here's the thing. There is NOTHING magical about a protection circuit that is going to keep a battery from going 'boom'. It can help prevent a battery from becoming overcharged, undercharged, or overdrawn. But the battery will do what it wants to do - protected or not. And when it comes to charging, what REALLY matters is the quality of your charger. A good charger will consistently cut off the charge very close to the proper voltage (4.2V for normal Li-Ion). Even charging your batteries somewhat over this (say, 4.3V) is not going to result in disaster. So I certainly wouldn't take things quite as far as ALWAYS charging on concrete or watching batteries like a hawk if you use good batteries and chargers. You probably don't want to put your batteries on the charger and go off to work. But if you are in the other room watching TV, you should be fine. Because a good charger will safely charge your batteries, protected or not.


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## recDNA (Jun 13, 2016)

A protection circuit can help prevent thermal runaway but not venting. It can also shut off in a short circuit and prevent overcharging. I have very well reviewed chargers but all electronics can and do go wrong sometimes. A protection circuit adds an extra layer of protection. You will not convince me otherwise. Do you think protection circuits designed by Sanyo are jokes? Fake? Don't bother replying. We will never agree on this issue.


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## StorminMatt (Jun 14, 2016)

recDNA said:


> A protection circuit can help prevent thermal runaway but not venting.



A protection circuit only helps to prevent conditions that can lead to thermal runaway. It can't actually prevent thermal runaway from occurring.


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## vadimax (Jun 14, 2016)

recDNA said:


> I have both but I prefer to use protected batteries if they fit. I'm always torn between unattended charging on a concrete garage floor and me watching charging on a porcelain plate on a wooden coffee table. I charge indoors where I can watch but find it stressful. I prefer to use primaries when possible because I hate charging so much. Never had a problem charging. Just aware.



Funny person you are  Somehow you manage to suffer flashaholism and batteryphobia at once


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## recDNA (Jun 14, 2016)

Maybe take a look at the sticky battery fire thread. It isn't phobia. It is rational caution.


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## Connor (Jun 14, 2016)

Fires/explosions are super rare in relation to the millions and millions of sold battery cells. And even less common on proper brand cells.

Only unprotected cells and good chargers for me. And voltage-aware flashlights.


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## markr6 (Jun 14, 2016)

Connor said:


> Fires/explosions are super rare in relation to the millions and millions of sold battery cells. And even less common on proper brand cells.
> 
> Only unprotected cells and good chargers for me. And voltage-aware flashlights.



Well put. Same here.


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## Gauss163 (Jun 14, 2016)

Connor said:


> Fires/explosions are super rare in relation to the millions and millions of sold battery cells. And even less common on proper brand cells.



Only because 99.9% of Li-ion cells aren't sold directly to consumers. Rather, they are encapsulated in professionally designed systems with adequate safety features (e.g. laptop and power tool packs). Only recently has consumer use of loose cells greatly increased (mainly due to vaping), and evidence of just how unsafe this can be can be seen by perusing the smoke and fire... subforum. 

Of course battery packs and charging systems can also be unsafe if incompetently designed, e.g. the recent "hoverboard" incidents.


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## Connor (Jun 14, 2016)

Gauss163 said:


> Only because 99.9% of Li-ion cells aren't sold directly to consumers. Rather, they are encapsulated in professionally designed systems with adequate safety features (e.g. laptop and power tool packs). Only recently has consumer use of loose cells greatly increased (mainly due to vaping), and evidence of just how unsafe this can be can be seen by perusing the smoke and fire... subforum.
> 
> Of course battery packs and charging systems can also be unsafe if incompetently designed, e.g. the recent "hoverboard" incidents.



True, but I'm only talking for myself as a knowledgeable and careful user. As such I don't benefit much/at all from protected cells (in conjunction with a good charger/flashlight and proper handling). 

If you don't know better and put a 35A unprotected cell in your pocket with your keys your burning pants will be your teacher. ;-)


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## Gauss163 (Jun 14, 2016)

Connor said:


> True, but I'm only talking for myself as a knowledgeable and careful user. As such I don't benefit much/at all from protected cells (in conjunction with a good charger/flashlight and proper handling)...



That's a different claim than your prior statistics based claim. Yes, of course, knowledge of safety guidelines can help one to be safer, but only if combined with the discipline to rigorously follow those guidelines without ever slipping up. Even experts may lack such discipline, e.g. the case of a hobby shop owner with decades of experience whose shop burned down when he left for 10 minutes while charging.


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## markr6 (Jun 14, 2016)

You can get killed walking your dog.

I park a 21 gallon gas tank in my home every night within feet from a 50ah battery and cabinet full of explosive tanks, chemicals and flammable items. I live dangerously.


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## Connor (Jun 14, 2016)

Gauss163 said:


> That's a different claim than your prior statistics based claim.



No, it's still the same "claim". If you are responsible for the fire by mishandling the cells in some way earlier, you are responsible for mishandling the cells (IMHO). 

I was talking about cells that explode/catch fire because of a manufacturing defect of some kind. Those failures are extremely rare and a protection circuit likely won't help at all if the cell fails internally (e.g. shorts internally while charging).

That doesn't mean I would recommend unprotected cells for everyone. The thread title is "18650 - Are protected batteries ALWAYS better?", though. IMHO they are not.


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## msim (Jun 14, 2016)

markr6 said:


> You can get killed walking your dog.



Very true! A crazy person threw a glass bottle at my dog and I one night while on a walk (it completely missed).


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## Gauss163 (Jun 14, 2016)

Connor said:


> No, it's still the same "claim". If you are responsible for the fire by mishandling the cells in some way earlier, you are responsible for mishandling the cells (IMHO).
> 
> I was talking about cells that explode/catch fire because of a manufacturing defect of some kind. Those failures are extremely rare and a protection circuit likely won't help at all if the cell fails internally (e.g. shorts internally while charging)...



Your original claim made no mention of manufacturer defects. But fyi internal shorts were reported to be the major causes of failures in laptop batteries a decade ago (before improvements were made to help manage internal shorts, e.g. ceramic separators).


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## Connor (Jun 14, 2016)

Fires/explosions still are a very rare occurrence even if you count in user error. Which I don't, because IMHO it's your own fault if you handle potentially dangerous technology without educating yourself properly. 
Regarding vapers: every good shop I've seen has strongly worded handling security information placed prominently on their website.


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## Gauss163 (Jun 14, 2016)

Connor said:


> Fires/explosions still are very rare occurrence even if you count in user error. Which I don't, because IMHO it's your own fault if you handle potentially dangerous technology without educating yourself properly.
> Regarding vapers: every good shop I've seen has strongly worded handling security information placed prominently on their website.



Depends on your definition of "rare". Most likely the frequency of incidents are at least an order of magnitude greater for consumer use of loose cells vs. cells used in competently professionally designed systems.


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## KeepingItLight (Jun 14, 2016)

Connor said:


> Fires/explosions still are a very rare occurrence even if you count in *user error*. Which I don't, because IMHO it's your own fault if you handle potentially dangerous technology without educating yourself properly.



I understand the point you are making, but I do not agree. We know, for instance, that many airplane crashes are caused by pilot error. That does not mean we should not design pilot-proof systems. 

Cell phones, tablets, laptop computers, and power tools all have built-in circuits to manage battery care. Unfortunately, flashlights do not. That is why I think there is a place for protected batteries in the flashlight world. 

In my opinion, flashlights need to have the same battery-protection circuits as the other products mentioned above. Period. 

I'll go further: Multi-battery flashlights should have full-on battery management systems, just like the rest of these devices. Each battery in a multi-battery device should have its voltage level independently monitored. Frankly, I think that the absence of such circuitry is a sign that the Li-ion flashlight industry is still in its infancy. 

When all flashlights have low-voltage cutoff circuits, then we can talk about eliminating protected batteries.

Can you really say that your flashlight will never be accidentally activated (and over-discharged)? Can you say that you will never put a flashlight down, and forget that it is on? 

I cannot. 

I got surprised recently by one of the Nitecore flashlights I own. Like many recent Nitecore releases, my *Nitecore P36* has a significant standby drain. It uses the batteries even when the flashlight is off. I usually unscrew the tail cap to lock mine out, but this time, I forgot to do that. When I came back a couple of months later, I found that one of its batteries had been drained to 3.6 volts. 

I learned something about my flashlight in this episode. For some reason the second battery in this 2x18650 model had not been depleted as much. 

The *KeepPower 3400mAh* batteries I use are a matched pair. They were purchased together, and they have always been used together. They are always charged together. Evidently, however, the standby drain does not discharge them at the same rate. Since these batteries only have a few cycles on them, I was surprised. Anyway, now I know about this, and I am keeping my eye on them.

And I am happy to report that these batteries are protected!


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## recDNA (Jun 14, 2016)

msim said:


> Very true! A crazy person threw a glass bottle at my dog and I one night while on a walk (it completely missed).


I was throwing the bottle at YOU! J/K

AW told me his IMR 800 mAh contains an internal heat resistant layer (HRL). I believe this is found in many Panasonic batteries. If there is a short outside the battery in the flashlight itself does HRL prevent thermal runaway?


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## recDNA (Jun 14, 2016)

Gauss163 said:


> That's a different claim than your prior statistics based claim. Yes, of course, knowledge of safety guidelines can help one to be safer, but only if combined with the discipline to rigorously follow those guidelines without ever slipping up. Even experts may lack such discipline, e.g. the case of a hobby shop owner with decades of experience whose shop burned down when he left for 10 minutes while charging.


Don't tell me stories like that. I'll be back in a gargage staring at my charger for 6 hours.


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## Gauss163 (Jun 14, 2016)

recDNA said:


> I was throwing the bottle at YOU! J/K
> 
> AW told me his IMR 800 mAh contains an internal heat resistant layer (HRL). I believe this is found in many Panasonic batteries. If there is a short outside the battery in the flashlight itself does HRL prevent thermal runaway?



Yes, ceramic separators help prevent thermal runaway, e.g. see The Role of Separators in Lithium-Ion Cell Safety by CJ Orendorff, Electrochemical Society Interface 21(2):61 · May 2012.


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## Dr. Mario (Jun 14, 2016)

Oooh, Ceramic separator. Panasonic, correct? I may be shopping for better IMR / INR cells soon.


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## recDNA (Jun 14, 2016)

Gauss163 said:


> Yes, ceramic separators help prevent thermal runaway, e.g. see The Role of Separators in Lithium-Ion Cell Safety by CJ Orendorff, Electrochemical Society Interface 21(2):61 · May 2012.


I had no idea they were ceramic. It was my impression it was just a thin membrane. Is there more than 1 type of HRL?


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## Gauss163 (Jun 14, 2016)

recDNA said:


> I had no idea they were ceramic. It was my impression it was just a thin membrane. Is there more than 1 type of HRL?



There are many, many different types of separators in use. Some have a multilayer structure that acts as a thermal fuse to inhibit thermal runaway, e.g. PE-PP bilayer, or PP-PE-PP trilayer membranes. Here the PE layer melts first, filling the pores in the other layers, which greatly inhibits ion flow. This increases internal resistance so much that current flow is reduced to near zero, so inhibiting thermal runaway. But the other layer(s) have higher melting points so they retain their mechanical strength, so they still keep the electrodes insulated. Also multilayer separators often have higher resistance to punctures.


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## Gauss163 (Jun 14, 2016)

Dr. Mario said:


> Oooh, Ceramic separator. Panasonic, correct? I may be shopping for better IMR / INR cells soon.




HRL (heat resistant layer) is Panasonic's name for their ceramic separators. Almost surely all of the top-tier manufacturers have made analogous safety improvements to their separators, but it is all proprietary so not easy to find public details. Also it is difficult to determine when these improvements first appeared, i.e. which older cells are less safe.


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## recDNA (Jun 14, 2016)

Do these separators react fast enough to stop thermal runaway in external short? I read it can take milliseconds.


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## magellan (Jun 14, 2016)

Gauss163 said:


> Yes, ceramic separators help prevent thermal runaway, e.g. see The Role of Separators in Lithium-Ion Cell Safety by CJ Orendorff, Electrochemical Society Interface 21(2):61 · May 2012.



Good article, thanks.


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## Gauss163 (Jun 14, 2016)

recDNA said:


> Do these separators react fast enough to stop thermal runaway in external short? I read it can take milliseconds.



Separators with shutdown capability are designed so that the separator fuses at temperatures much lower than the thermal runaway temperature. Thermal runaway typically takes minutes, not msecs (but the actual time depends on many parameters).


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## recDNA (Jun 14, 2016)

Gauss163 said:


> Separators with shutdown capability are designed so that the separator fuses at temperatures much lower than the thermal runaway temperature. Thermal runaway typically takes minutes, not msecs (but the actual time depends on many parameters).


Thanks. That's good news. Makes me feel a little safer using an unprotected battery.... Assuming it really does have the HRL. No way for user to really check.


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## staticx57 (Jun 14, 2016)

I would imagine in cell protections would cause something like this: 
instead of something like this:


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## StorminMatt (Jun 15, 2016)

recDNA said:


> Thanks. That's good news. Makes me feel a little safer using an unprotected battery.... Assuming it really does have the HRL. No way for user to really check.



This is certainly one of those situations where it is best to buy quality cells.


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## Dr. Mario (Jun 15, 2016)

staticx57 said:


> I would imagine in cell protections would cause something like this



Correct. It's the primary purpose for heat resistant layer (HRL) ceramic separator - that is, preventing disastrous cell meltdown from really occurring.

And, yes, I agree. Buy the quality cell. You will never know if and when you will need the specification "cushion" and safety design when things go AWOL.

BTW, I wonder about this store: liionwholesale.com - is it legit or not? (If URL link is not permitted, I will edit it so you guys can google search for it). I usually go to Powerizer Batteryspace for my cell fixes, including the elusive A123 LiFePO4 cells.


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## space-cowboy (Jun 16, 2016)

There are many informations here that are not correct.
I can write the whole page here....but basically here it is in a few words:

HRL has nothing to do with shutting down the cell in case of dead short (external).
High drain batteries are not safer than regular NCR Panasonic batteries (it is quite opposite). 
The whole thing about safe chemistry is misunderstood.
Try to short one High Drain (rated 10A, and higher) cell, and one bare NCR18650B - see what happens.
Device (inside NCR Panasonics A, B, G series) that should protect against thermal runaway (when dead short happens) is called PTC.

Now the bad part about bare unprotected cells that people do not know:

Any unprotected cell that is rated above 10A is *without *PTC.
Manufacturers have to take it out to maintain low int. resistance, and performance under high load.
So it is basically your high Amp cell and you (and dead short that will eventually happen - better not  )

On that video above you can clearly see why we not suppose to use Unprotected 18650 batteries.
It is *very *dangerous, and protection should be attached to the bare cell.

This video is for all those who Like to recommend Unprotected 18650 . Watch how safety layers inside bare battery can protect you 
https://youtu.be/xS8LsPv1_uM


About that store: Selling fake rated batteries to naive people (mostly from vape community). 35 Amp, 40 Amp, 60 Amp - all fakes, and dangerous.

When battery seller (any seller) knowingly post fake data in product title: "35A battery" or "60 Amp battery", 
and he knows that Amp limit is nowhere close to that fake rating then that same battery seller is also knowingly exposing his customers to some serious risks of injury.
So much about being legit and honest to the customer.


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## Connor (Jun 16, 2016)

space-cowboy said:


> https://youtu.be/xS8LsPv1_uM



So this guy put a 18650 (likely a high drain one too) in his pockets with his keys/whatever where it shorted and had time to cook up to critical temperature and vent with flame. 
I'm sure this was very scary and hurt a lot but my compassion is limited. You can't handle any 18650 like that .. because . 

#usererror


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## pse (Jun 17, 2016)

space-cowboy said:


> Unprotected 18650 batteries.
> It is *very *dangerous, and protection should be attached to the bare cell.
> https://youtu.be/xS8LsPv1_uM



What do think about Zebralight? The lights have inbuilt protection, according to ZL of higher quality then the Seiko ones used in protected cells. They said, that the thin wire from the PCB under the wrapper was a concern, therefore new models are compatible only with unprotected cells...


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## CoherentRays (Jun 17, 2016)

Dr. Mario said:


> BTW, I wonder about this store: liionwholesale.com - is it legit or not? (If URL link is not permitted, I will edit it so you guys can google search for it). I usually go to Powerizer Batteryspace for my cell fixes, including the elusive A123 LiFePO4 cells.


Yes, Liion is legit. I placed an order about 3 weeks ago and got everything I ordered quite quickly. You get a price break if you order 4 or more batteries and I think the next price break is at 25 or more. At that point everything in your cart shows another price decrease. 

Ed


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## Dr. Mario (Jun 17, 2016)

CoherentRays, thanks for confirming.


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## Dr. Mario (Jun 17, 2016)

I have been using unprotected cells and no disasters so far because I knew better after an extremely close call. (Made a mistake years ago when I was building a battery pack - which is ironic because it occasionally is dangerous to put a protection circuit on the bare cells, one mistake and it's over. I now know to check every cells' polarity before I put on buss strips, and finally connect it to the BMS.)

I haven't forgotten all the bangs and fires. Now I check every single bare cells that sees some uses, and recharge them if necessary - and discard those expired cells.


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## super kermit (Jun 18, 2016)

I would rather pay more for the batteries and be sure they are *100% real and legit.*

Who is the *best seller* to buy *protected 18650*'s from and specifically which* brand and model* should I buy please.


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## recDNA (Jun 18, 2016)

super kermit said:


> I would rather pay more for the batteries and be sure they are *100% real and legit.*
> 
> Who is the *best seller* to buy *protected 18650*'s from and specifically which* brand and model* should I buy please.


Are you in USA?
Tell us the flashlight you want them for. Protected batteries may not fit in every flashlight. There are button top and flat top. And again some flashlights require the button and in others they are even tighter with the button.

Understanding that without the above info I can only guess if this battery is best for you one good choice is Orbtronic 3500mAh Protected 18650 Battery Li-ion 3.7V Rechargeable Orbtronic 10A (Panasonic inside) Dual Protection - For High Performance Flashlights - Case Included

You buy directly from Orbtronic in USA. I don't think it is allowed for me to paste a link but you will have no trouble finding Orbtronic by Googling.


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## super kermit (Jun 18, 2016)

I am in Australia and would need shipping.

I need the button top.


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## super kermit (Jun 18, 2016)

Hi recDNA,

Awesome advice and thank you for answering my Q

Just looked and battery looks amazing, but the shipping on 10 batteries is $55 US.

Any better options for using a different site to save some money on shipping?

OR

different brand that also has dual protection please?

If I cannot get the orbtronics for cheaper shipping and went for a different brand/model and site, which would you suggest.

Thanks again for taking the time to reply to a newbie too


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## recDNA (Jun 18, 2016)

I don't know who is the official dealer for Olight in Australia but they make a good protected button top also.


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## super kermit (Jun 19, 2016)

recDNA said:


> I don't know who is the official dealer for Olight in Australia but they make a good protected button top also.



Great, any olight is ok as long as protected?


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## oKtosiTe (Jun 19, 2016)

super kermit said:


> Great, any olight is ok as long as protected?



Olight was too long for my EagleTac G25C2-II. It really helps to know what light you're buying for.


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## recDNA (Jun 19, 2016)

oKtosiTe said:


> Olight was too long for my EagleTac G25C2-II. It really helps to know what light you're buying for.


Very good point! If we knew the flashlight we could give better recommendations. I only went with Olight because of the op expressed desire for safety. I think the new ones may have the safest protection (no wire in the side) but they are also very long.


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## Gauss163 (Jun 19, 2016)

space-cowboy said:


> ...HRL has nothing to do with shutting down the cell in case of dead short (external)...



But it does if Panasonic's "HRL" (or its latest incarnation) incorporates a multilayer separator design with shutdown capability (as I described above).


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## recDNA (Jun 19, 2016)

Gauss163 said:


> But it does if Panasonic's "HRL" (or its latest incarnation) incorporates a multilayer separator design with shutdown capability (as I described above).


Trouble is we don't know for sure which Panasonics have it. It's the GA I'm curious about. Maybe some lunatic on YouTube will test it.


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## Gauss163 (Jun 19, 2016)

recDNA said:


> Trouble is we don't know for sure which Panasonics have it. It's the GA I'm curious about. Maybe some lunatic on YouTube will test it.



Right, most of this information is proprietary and is not made available to the general public. As such, to be safe, lacking specific information to the contrary, one should assume that the separator does not include fusing shutdown capability. This is certainly true for older cells (such as those pulled from older laptop packs).


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## Connor (Jun 19, 2016)

All modern cells with a PTC thermistor design *should *shut down in case of an external short. And like anything (given the right circumstances) these protections can and will fail. 

Panasonic's HRL is meant to _improve _protection against overheating in case an internal short occurs. Certainly "nice to have" but it does not mean those cells can't overheat/vent with flame anymore.


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## Gauss163 (Jun 19, 2016)

Connor said:


> ... Panasonic's HRL is meant to _improve _protection against overheating/venting in case an internal short occurs. Certainly "nice to have" but it does not mean those cells can't overheat/vent with flame anymore.



HRL is very old tech. The latest separator innovations include additional shutdown fusing capability (among other improvements). See the links I gave above.


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## Connor (Jun 19, 2016)

I did see  and I applaude innovations that make LiIon/LiPoly cells more secure. There's still ~12 Whs of energy stored in a little metal can and IMHO it would be foolish to think those cells can't go  anymore - it just became somewhat less likely.


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## recDNA (Jun 19, 2016)

Connor said:


> I did see  and I applaude innovations that make LiIon/LiPoly cells more secure. There's still ~12 Whs of energy stored in a little metal can and IMHO it would be foolish to think those cells can't go  anymore - it just became somewhat less likely.


Since some flashlights now require unprotected cells (unfortunately) any additional protection is appreciated imo. I love the idea of the new protected Olight which has no wire from + to - which is a common source of problems however I'm not sure it actually fits in ANY flashlights. All I hear is "too long"


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## Gauss163 (Jun 19, 2016)

@Connor Right, said safety improvements decrease the probability of failure (I don't recall any claims that they are 100% effective).


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## TinderBox (UK) (Jun 19, 2016)

YES, YES, YES, only $4 - "2pcs 3.7V *18650 9800mAh* Li-ion Rechargeable Battery For UltraFire LED Flashlight" 

John.

*EDIT: DO NOT BUY, DO NOT BUY, TOTALLY FAKE CAPACITY
*
http://www.aliexpress.com/item/2pcs...hnUTT_37002_$8052c302b6b24ccb805e36df0e089123


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## Gauss163 (Jun 19, 2016)

The outrageous "10000mAh" fakes have been discussed here before, e.g. here. The eBay feedback says they are really between 400-950mAh, and includes a couple reports of ventings and explosions. But, scarily, 99.9% of the feedback is positive - which says something about the knowledge-level of the general public on such matters.


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## TinderBox (UK) (Jun 19, 2016)

So either the feedback is fake, or a lot of the buyers don't have a way of checking the capacity, maybe e-cig owners, they can use 18650 right?

John.



Gauss163 said:


> The outrageous "10000mAh" fakes have been discussed here before, e.g. here. The eBay feedback says they are really between 400-950mAh, and includes a couple reports of ventings and explosions. But, scarily, 99.9% of the feedback is positive - which says something about the knowlegde-level of the general public on such matters.


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## Gauss163 (Jun 19, 2016)

TinderBox (UK) said:


> So either the feedback is fake, or a lot of the buyers don't have a way of checking the capacity, maybe e-cig owners, they can use 18650 right?



From what I could infer, the feedback is probably (mostly) legit. The inaccurate massive positive feedback probably has more to do with the fact that nowadays (with vaping etc), by far and away the majority of 18650 users are not as technically minded as in communities like this. So not only do they not have devices that can do capacity tests, but they are not even aware of the need for such, having never heard about the rampant fraudulent inflated capacity claims. Even more scarily, they are probably also not aware of the potential dangers. But that is probably old news to anyone who has keeps up to date on the Smoke and Fire... subforum.


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## super kermit (Jun 19, 2016)

Buying these at the moment, but only as a test.

I expect roughly 50% of real lumens/lux vs claimed.

http://www.ebay.com.au/itm/381294654647?_trksid=p2057872.m2749.l2649&ssPageName=STRK:MEBIDX:IT

http://www.ebay.com.au/itm/331749348797?_trksid=p2057872.m2749.l2649&ssPageName=STRK:MEBIDX:IT

http://www.ebay.com.au/itm/271975369607?_trksid=p2057872.m2749.l2649&ssPageName=STRK:MEBIDX:IT


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## staticx57 (Jun 19, 2016)

super kermit said:


> Buying these at the moment, but only as a test.
> 
> I expect roughly 50% of real lumens/lux vs claimed.
> 
> ...



You will be wasting your money with all those. Post in the recommend me a light section if you want solid suggestions.


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## msim (Jun 19, 2016)

staticx57 said:


> You will be wasting your money with all those. Post in the recommend me a light section if you want solid suggestions.



Agree. Those are all garbage.


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## vadimax (Jun 20, 2016)

Gauss163 said:


> From what I could infer, the feedback is probably (mostly) legit. The inaccurate massive positive feedback probably has more to do with the fact that nowadays (with vaping etc), by far and away the majority of 18650 users are not as technically minded as in communities like this. So not only do they not have devices that can do capacity tests, but they are not even aware of the need for such, having never heard about the rampant fraudulent inflated capacity claims. Even more scarily, they are probably also not aware of the potential dangers. But that is probably old news to anyone who has keeps up to date on the Smoke and Fire... subforum.



That just confirms Einstein's words about infinite stupidity  Most people do not even care to study an item they are going to pay for.


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## stephenk (Jun 20, 2016)

super kermit said:


> Buying these at the moment, but only as a test.
> 
> I expect roughly 50% of real lumens/lux vs claimed.
> 
> ...


Maybe remove the zero from your percentage expectation. Better pre-warn your local fire brigade too.


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## Gauss163 (Jun 20, 2016)

vadimax said:


> That just confirms Einstein's words about *infinite stupidity*  Most people do not even care to study an item they are going to pay for.



Nitecore has a solution: they now offer an infinitely intelligent charger - a match made in Heaven (or, actually, fiery Hell).


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## vadimax (Jun 20, 2016)

stephenk said:


> Maybe remove the zero from your percentage expectation. Better pre-warn your local fire brigade too.



Good one about fire brigade


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## mulletbay1 (Mar 10, 2019)

Hi. I need a good set of 18650 cells for my Thrunite tn42 What is suggested gor button tops without spending a fortune??? Thanjs Williami


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## 3L3M3NT (Mar 29, 2019)

mulletbay1 said:


> Hi. I need a good set of 18650 cells for my Thrunite tn42 What is suggested gor button tops without spending a fortune??? Thanjs Williami



Here are some of the batteries that I'd suggest.
https://liionwholesale.com/collecti...nyo-ncr18650ga-button-top?variant=12534255236

http://www.mtnelectronics.com/index.php?route=product/product&path=59_88&product_id=289

https://www.illumn.com/batteries-ch...panasonic-ncr18650g-protected-button-top.html

https://www.orbtronic.com/3600mah-18650-li-ion-orbtronic-panasonic-rechargeable-battery

https://www.batteryjunction.com/efest-3259-pc-button.html

I'm sure you can look through each of the sites I linked and find some more affordable batteries.


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## delus (Mar 1, 2020)

Hope it's OK to bump an old thread rather than start a new one, my concerns are similar to those discussed above, but a bit different. 
Also, Kudos to staticx57 who posted those two videos back in post 62.

Protected vs Unprotected when used in series. 

Years ago I had the tube of an Elzeta Charlie bored to fit two 18490 cells. (18500 are a little too long in this application.) At that time I got two sets of AW-brand protected cells and everything was great until two years ago when I started daily carrying the charlie. I quickly found out that you have to get those cells on the charger way before the light dims or the cell towards the switch will be over discharged while the cell towards the head would still be at 3.4 volts or so. 
My LUC-V4 charger would report one cell at zero volts (protection had tripped) while the other was still in the middle of it's range. Fortunately, this charger does have a recovery feature, and it can bring them back from the dead... Well, *sometimes *it can bring them back from the dead. in two years I have ruined five sets of batteries. The last straw was last week when a new cell would not recover after only two charge cycles.

Belatedly, I start to think about it. It seems like every time a cell dies I have been using the light continuously for more than a few minutes. So I put it to the test.

First some actual data:
The 4 older cells were AW-brand, 18490, button top, 1100 mAh, 4.1w/h, red, made in China. I still have one that takes a charge.
The 6 newer cells were IMREN brand, 18490, 1100mAh, blue, made in China. I have two that still take a charge.
Both brands have the ring near the positive end, indicating they are protected cells. 
I do not know the exact voltage the protection circuit is supposed to trip.
I do not notice any difference in their overall performance. The AW cell is maybe 1mm taller.
The Elzetta AVS Auto-voltage-sensing driver does not pull huge amperage. Elzetta reports that in a 3-cell charlie configuration it pulls 1.3A. Not exactly sure what it pulls in this 2-cell configuration. Probably closer to a Bravo's 1.1A.

So I'm gonna run two tests. I have only two good, matching cells, and I think I know what kills them, so I have to run this test first. 
Test 1: 
I get out a 3 minute egg timer. Of course start with batteries allowed to settle for an hour after charging.
I run the light - on 3 minutes - off 3 minutes. I do that ten times for a total of 30 minutes runtime.
One cell reports 3.4V, the other 3.3V.
Test 2: 
I run the light for 30 minutes continuously.
One cell reports 3.5V, the other 3.2V.
AHA! According to my single unscientific test, I can avoid tripping the protection circuit by NOT running the light for more than 30 minutes continuously, and allowing the batteries to have rest periods between shorter runtimes is preferable. 

Now the questions. It's time to get more cells.
It's always the cell at the negative end of the circuit that produces the low voltage. At the end of test 2, it's best to set the cells aside until they can be charged, but would it be a good idea to flip them, so the lower voltage battery is now on the positive end, then allow some rest time? Would their voltage now even out? 
From a safety standpoint, How bad would it be to use unprotected cells in this configuration? Would I end up with dendritic short circuits? Pants on fire?

Why don't I see a thousand people complaining that their batteries over-discharged in four-cell lights? That's usually a 2+2 configuration, right? AFAIK the Noctigon Meteor is the only 4-cell parallel light.


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