# Why Use Unprotected While Protected Works Fine?



## fivemega (Dec 13, 2016)

*Many people still don't know why and when to use protected or unprotected.
If you are using unprotected cells, do you have scientifically good reason for that? And same thing for protected cells. Why do you use them?
There have been many, many and many threads for same question but nobody can proof one is better than another or vs versa.
So what do you use and why? (One or multiple serial) Any scientific reason?

I personally use protected cell (in any configuration) when I can and when they work without problem and safely.
I use IMR (unprotected) cells where protected cells won't work properly or at all such as 2C+ or over capability of protection PCB.*


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## Lexel (Dec 13, 2016)

There is no such thing as unprotected cells if you dont buy Ultrafire fakes.

Quality cells got temperature/overcurrent bimetal switch and a vent valve cutting the positive contact when the cell starts to vent.

PCB is a fast overcurrent shut down
protects from overcharge but often 0.1V too much is not healthy
protects from overdischarge

if you flashlight got low voltage cutoff without parasitic drain and you use a good charger there is nothing wrong using cells without PCB

even those 8A PCB cells got a lot voltage drop on the PCB on high currents


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## StorminMatt (Dec 13, 2016)

There are a few reasons why I use unprotected cells:

1. They fit in lights better both in length AND diameter.
2. There is no risk of damage to a light from an excessively long battery from spring pressure and/or binding.
3. They are cheaper. This is particularly true in the case of overpriced flashlight-branded protected cells.
4. You avoid the voltage drop associated with a protection circuit.
5. You have more choices when it comes to cells - generally only a few cells (ie the most popular ones) are available protected.
6. Protection circuits limit maximum current draw - NO truly high current cell can have on-board protection for this reason.
7. There is no risk of short circuit between the negative battery can and positive strip along the side.
8. There is no risk of short circuit from physical damage to a protection circuit (such as from a drop).
9. Some lights can't use protected cells (ie Zebralights).
10. Protected cells can unexpectedly leave you in the dark (unlike protected lights, which step down before cutting out).
11. Cells are generally safer nowadays due to safer chemistries, built-in failsafes, and wider availability of quality cells (and bad cells are easier to avoid).
12. Most quality lights have good low voltage protection.
13. Quality chargers that won't overcharge are inexpensive and widely available.
14. It's really not THAT hard to properly care for unprotected cells and avoid overcharge/overdischarge.
15. You will actually learn to care for your batteries BETTER if you use unprotected cells. FOR REAL!


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## staticx57 (Dec 13, 2016)

I personally use cells without PCBs in all cases where there is NO reason not to use them. Reasons not to use them: lights with parasitic drain, lights with no voltage warning, cells in series, letting someone unfamiliar with Li-ion borrow my light.

These days even $10 lights have drivers with low voltage warning.


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## hiuintahs (Dec 13, 2016)

I personally use unprotected cells where possible because they are less money. Being an electroincs guy, I guess, I don't have the fear some have and I'm pretty aware of where the charge is at on the battery. Also I have seen that the light dims pretty obvious when the voltage gets down below 3.0v. I just won't bother to run the light anymore when that happens. But most of the time, I top off my batteries before it's ever a problem. I have no lights that have parasitic drain and so that isn't an issue. When doing a run time test where I won't be around, I'll use a protected battery. Some of my flashlights require button tops and since most protected batteries come with button tops, then that's the reason I would use one.


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## MAD777 (Dec 13, 2016)

All my batteries are unprotected. That's well over 60 batteries and never a problem. Most all my flashlights are super modded and protected batteries simply can't supply the juice to keep up.


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## Timothybil (Dec 13, 2016)

For the most part, those of us on here are intelligent enough and experienced enough to know how to use and care for unprotected cells properly. Most of the NOOBs are asking good questions and learning from our discussions and answers to their questions. There is always going to be those few who don't believe rules or guidelines are meant for them, and that they know better than the collected wisdom available here. Some are Darwin Award winners or runners up, others haven't gotten that far yet.


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## vicv (Dec 13, 2016)

When I started getting into flashlights I also started vaping soon after. IMR type cells are necessary for vaping and they also worked well in my lights. I also enjoy pocket rocket incans so small imr cells can handle the higher current much better and capacity difference isn't much in the 35mm long cells. Also from my 2 protected cells I bought they were the recommended aw cells. Worst cells I've ever owned and turned me off of non high drain expensive protected ones. Ive hardly ever run one down too much and when I have they handle it much better than a lico chemistry. I don't mean to make this a lico vs imr thing but that's how it worked out. And today's high drain 18650's are basically better in every way to a new protected cell. Better current supply, higher voltage for brighter output or longer regulated output, just as much if not more useable capacity, more robust, cheaper, and probably safer chemistry


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## chillinn (Dec 13, 2016)

you're using Li-ion, you need to have some good sense with them whether the circuit is there or not. ... If you have knowledge of Li-ion cells, and do not abuse them, use quality cells, a quality charger, and adopt best practices, then there is little point to the protection circuit. It is simply poor practice to mindlessly use a Li-ion cell, and it is irresponsible to not be mindful of the state of charge of the cell, so have some idea.

Also, I find invariably that new users are lulled into a false sense of security and make the mistake of assuming the protection circuit is protecting the user from catastrophic cell failure and injury, when I simply don't see that as strictly true. I feel it is far more accurate to look at that protection circuit as protecting the cell from user abuse, and not protecting the user in any meaningful way while the cell is being used. I think one is better off with out that delusion, but instead rely on education, gaining experience with the discharge curve "knee," to tell them they've gone too far rather than a tripped circuit. It is better to be fastidious in acquiring quality cells from a reputable dealer, and a quality charger, than to trust a protected cell simply for that little circuit.

Though not recommended at all, you can run your unprotected Li-ion cells in your lights down to zero charge, and they are not going to explode in your hand. But the cell will be ruined, and you should know never to attempt to recharge it. If you wish to be wreckless, a protection circuit is not really going to protect you, and you're going to get creamed sooner or later, because that kind of attitude is... well, wreckless and irresponsible.


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## StorminMatt (Dec 14, 2016)

** Deleted **


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## Woods Walker (Dec 14, 2016)

fivemega said:


> *Many people still don't know why and when to use protected or unprotected.
> If you are using unprotected cells, do you have scientifically good reason for that? And same thing for protected cells. Why do you use them?
> There have been many, many and many threads for same question but nobody can proof one is better than another or vs versa.
> So what do you use and why? (One or multiple serial) Any scientific reason?
> ...


I have some though hardly anything I do is scientific. I guess the reasons are cheaper and higher drain than some options as there is no protection circuit to trip. Also some protection circuits don't allow the battery to be charged to it's full capacity or so some have said. Or have they? Who knows but some lights have their own protection built in. Some also don't fit protected batteries as the length is too long. Personally I only would use them in lights and devices which shut down around 2.6 or so volts. I don't use them in battery vampires but that's just me.


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## stephenk (Dec 14, 2016)

Woods Walker said:


> I have some though hardly anything I do is scientific. I guess the reasons are cheaper and higher drain than some options as there is no protection circuit to trip. Also some protection circuits don't allow the battery to be charged to it's full capacity or so some have said. Or have they? Who knows but some lights have their own protection built in. Some also don't fit protected batteries as the length is too long. Personally I only would use them in lights and devices which shut down around 2.6 or so volts. I don't use them in battery vampires but that's just me.


If a protection circuit is preventing full charging there would be something wrong with it. Most protection circuits (based on published specs) will stop overcharging of 4.2V cells at 4.25V. Thus the protection circuit acts as redundancy in case the charger fails to terminate charge.


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## parametrek (Dec 14, 2016)

My favorite li-ion chemistry (LiFePO4) doesn't really need protection and no one bothers to put it on.

And of course NiMH doesn't need it either


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## HKJ (Dec 14, 2016)

parametrek said:


> My favorite li-ion chemistry (LiFePO4) doesn't really need protection and no one bothers to put it on.



Of course it is not very safe without protection. A A123 26650 cell is rated for 150A discharge and will deliver considerable more if shorted.
A normal protection circuit would not work at these current levels, the only solution is to be very careful.


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## n3eg (Dec 14, 2016)

fivemega said:


> *If you are using unprotected cells, do you have scientifically good reason for that? There have been many, many and many threads for same question but nobody can proof one is better than another or vs versa.
> So what do you use and why? (One or multiple serial) Any scientific reason?
> 
> I personally use protected cell (in any configuration) when I can and when they work without problem and safely.
> I use IMR (unprotected) cells where protected cells won't work properly or at all such as 2C+ or over capability of protection PCB.*



OK then, why use protected when unprotected works fine?

I use them for the higher peak current, extra 0.6 volts, and not having to zap cells when they drop below a certain point. I've worked with batteries in one way or another for over 40 years. I never had a battery explode or "vent with flame", and have only wrecked one set of four crap NiMH batteries which shorted in the charger. I match cells in packs. I regularly solder to lithium batteries with no trouble at all. I'm not the person who needs protected cells.


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## StorminMatt (Dec 14, 2016)

n3eg said:


> OK then, why use protected when unprotected works fine?



That's probably a better way to put things. The way I see things, protected cells make LOTS of concessions (ie price, fit, and performance, and others) for the sole purpose of providing a line of defense against gross negligence. It is really not that difficult to safely use unprotected cells, especially with quality single cell lights with built-in protection and good chargers.




HKJ said:


> Of course it is not very safe without protection. A A123 26650 cell is rated for 150A discharge and will deliver considerable more if shorted.





HKJ said:


> A normal protection circuit would not work at these current levels, the only solution is to be very careful.




Protection circuitry for these sorts of cells is in the device (which is where it belongs), NOT the cell itself.


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## swan (Dec 14, 2016)

Some lights can use protected cells some cannot.

I think these days of high current demand lights, in built charging, multi cell, duel chemistry with wide voltage input it is most important to pick the most appropriate cell for each individual light.

For me i like to run protected cells in big multi cell lights like the tk 75 and unprotected in single cell lights. Being experienced li ion user i choose to run two unprotected high drain 18350 in series in my modded m2x ut for shear out put and full lux right down low in voltage. [stuff runtime]

But for people who do not possess a multi meter or unfamiliar with the dangers of li ion i always recommend a light that runs protected cells.

Both are equally safe sitting on a shelf- what makes them dangerous is how a individual uses them.


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## Woods Walker (Dec 14, 2016)

stephenk said:


> If a protection circuit is preventing full charging there would be something wrong with it. Most protection circuits (based on published specs) will stop overcharging of 4.2V cells at 4.25V. Thus the protection circuit acts as redundancy in case the charger fails to terminate charge.


As stated this is something I have heard not something I have observed.


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## HKJ (Dec 14, 2016)

StorminMatt said:


> Protection circuitry for these sorts of cells is in the device (which is where it belongs), NOT the cell itself.



Mostly both protection and the batteries is in a sealed battery pack with welded connections, like the battery manufacturers require.


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## vicv (Dec 15, 2016)

stephenk said:


> If a protection circuit is preventing full charging there would be something wrong with it. Most protection circuits (based on published specs) will stop overcharging of 4.2V cells at 4.25V. Thus the protection circuit acts as redundancy in case the charger fails to terminate charge.



I think he means for the 4.3 and 4.35 V cells


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## psychbeat (Dec 15, 2016)

I've had two AW protected 2600 short on me (scary). 
One form being dropped and the other from a snag in a battery carrier. 
In some instances I've concluded that protected can be more dangerous with that thin little flat wire running the length just waiting to short. 

Nothing against AW here btw - I use his "IMR" 18350s & 16340s 

I've even removed the PCB from the rest of my AW2600s and rewrapped. 
They're old but work fine for low drain lights. 

I only buy raw name brand cells from trusted vendors now. 
GAs & Qs have me covered.


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## chillinn (Dec 15, 2016)

psychbeat said:


> I've had two AW protected 2600 short on me (scary).
> One form being dropped and the other from a snag in a battery carrier.
> In some instances I've concluded that protected can be more dangerous



This is very interesting. Can you please be more specific? Are you saying the protection strip itself shorted the cell? What, exactly, do you think happened there? Thanks.


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## markr6 (Dec 15, 2016)

StorminMatt said:


> There are a few reasons why I use unprotected cells:
> 
> 1. They fit in lights better both in length AND diameter.
> 2. There is no risk of damage to a light from an excessively long battery from spring pressure and/or binding.
> ...



HAHA "a few". I agree with all this :thumbsup:


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## psychbeat (Dec 15, 2016)

chillinn said:


> This is very interesting. Can you please be more specific? Are you saying the protection strip itself shorted the cell? What, exactly, do you think happened there? Thanks.



On both occasions the thin flat wire shorted to the metal case. Once, on the edge near the positive end and the other near the neg end when the cell was dropped. 

When this happens you need to watch out as the flat wire heats up quickly and will melt the wrapper. 
Both of the cells were fine after I removed the PCB and rewrapped. In fact, I'm still using them regularly. 

These were genuine cells purchased directly from Andrew's old thread on CPFMP.


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## psychbeat (Dec 15, 2016)

markr6 said:


> HAHA "a few". I agree with all this :thumbsup:



+2!


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## peter yetman (Dec 15, 2016)

I've had the PCBs fail on a couple of my protected AW cells and removed them to use unprotected. You're right about that wire strip, if it shorts it glows red hot - very scary.
In view of the PCB issue and the fact that the light just extinguishes when the circuit trips in, I'm going to buy unprotected from now on. I've played with LI-Ions for a few years now and know how to treat them with respect thanks to this Forum.
But I would still recommend protected cells to new users.
P


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## Dr. Mario (Dec 16, 2016)

I personally use unprotected Lithium-ion batteries mainly from the point of view on usage risks; as I have firmware-defined LED flashlights (eg, those using Nanjg AK-47A with ATTINY microcontroller in use), so battery discharge limits aren't the biggest concern as the software on all of my DIY flashlights cut out at 2.8 - 3 Volts (although I will have to raise the cutout voltage on a few flashlights for a few special INR 18650 cells such as LG MJ1 which is best cut off at 3.5 Volts for lifespan reasons).

Protected cells work just fine for my usage, however, as the others pointed out, is that there is concerns with the Anode strip which can chop through the Kapton tape (yellowish tape which can resist some serious heat), causing short-circuit which the 18650 cells can dump up to 60 Amps of current into, heating up the cell significantly, possibly initiating the thermal runaway - I prefer to use the protected cell with the original wrapper intact as they usually offer better protection than the Kapton tape, but you never know, especially with most circuit breaker board's components exposed in the cell spacer (the bottom plastic piece at (-) end of cell, holding the circuit breaker board), as it's the most vulnerable spot. I prefer to use it in the flashlights I don't expect to drop. For that flashlight, unprotected Lithium-ion batteries is used instead as circuit breaker function is to be handled by the firmware on the LED driver.


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## peter yetman (Dec 17, 2016)

Nice explanation, Doc.
P


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## Lou Minescence (Dec 17, 2016)

After reading the posts here I ask someone to change the title of this thread
" Why Use Protected While Unprotected Works Fine ?
[emoji3]
I use both types of batteries but prefer to use protected where possible. I have about 60 lights and it is getting to be a hassle trying to remember what light can and can't take which battery. 
The 5 years ago battery threads were all about how crazy it was to use non protected batteries. Times have changed. I do like the fact non protected batteries are cheaper than protected. If you suspect a problem get rid of the $6 non protected battery. When the protected battery costs $15 I think a little harder about disposing of it.


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## ven (Dec 17, 2016)

I only use protected cells if i need the extra few mm for contact or simply because i still have a few and to use them.................certainly not for the PCB. They still have a place imo, but if they are relied on or cause the user to become complacent thinking the PCB will save them, then again its misguided imo and the chemistry protected or not is not for them.

Education and common sense(ironically which is not that common) are key, after all you can have all the protection you want in a car, air bags, abs, active this,that and the other..............they still crash and thats after lessens,courses etc. Joe public can go buy these cells with no knowledge, stick them in a device and use till flat. Slap them on a *****fire charger overnight, forget about them till they get in from work. They dont know their fake 4000mah cell is not 4.6v, they then stick it in ther $5 light and probably get away with it for weeks, months..............then! People will still chuck an 18650 in their pocket/bag with lots of keys and other metal objects next year, and the year after. Again they will probably get away with it for weeks..........heck maybe years till...........! 

You buy a sharp knife, you know it can chop your fingers off, but people still do................human nature i guess.

Our motto is all accidents are preventable, which is true, yet we still stub our toes and bump our heads. Education, warnings and CPF is the answer to reduce incidents.

As above, cells are cheap, if unsure, or over discharged and left for an unknown period, recycle................easy as that. No one is perfect, but we learn from our mistakes(hopefully), many dont who seem to appear on the news and most of that i would put down to education/ignorance. 

imo, not saying i am right in anyway, just my thoughts. Today, with cell chemistry and driver tec, things are very different than 5yrs+ back.


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## TinderBox (UK) (Dec 17, 2016)

I only use protected cells in flashlights that take more than 1 li-ion cells to protect me against out of balance cells.

Protected cells in flashlights can leave you in the dark when the low voltage protection kicks in, not something you want to happen in an emergency.

John.


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## Thom2022 (Dec 17, 2016)

As someone who's been vaping on mech mods for years I only have unprotected cells for use when my flashlight finally turns up. They are fine to use in series will a little common sense. Only use married pairs and label them A and B and after ever charge switch their position in the light so the load is shared equally over time. I keep a log book next to my charger that has voltage after use, voltage after charge, total charge time and last position in the battery sled. Yes it takes up a bit of time but there's no substitute for safety.


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## Dr. Mario (Dec 17, 2016)

Of course, protected Lithium-ion batteries do still have their place, especially in the multi-celled flashlight which you do need a lot of redundancy to ensure it stay safe - most circuit breakers trip if there is inconsistency in current consumption.

On the other hands, they're kind of useless in the pocket rockets except for low power mode which they're still okay for use in a pinch. Most low drain protected 18650 cells trip out at 2 - 5 Amps which is not good enough for usage in the triple LED pocket rockets.

And yup, common sense still applies. I'd recommend to buy a cheap DMM (digital multimeter) to check the battery voltage to judge whether it has enough juice or not, and to be sure multiple 18650 cells are within 1 - 10% of each other if you chuck them all in multi-celled flashlight, and it's also therefore much more strict when you use them in vapers (since they're more abusive than flashlight from current consumption standpoint - not all vapers are created equal, however, a few vapers use DC-DC buck converter which usually mean less current demand on batteries depending on wattage settings).

And no Ultrafire batteries. Genuine XTAR chargers (and a few other respectable brands) can be had from the cigar shops and Amazon websites - you have to confirm if it's genuine though as it's easier to get the fakes nowadays. Genuine chargers and genuine batteries are every flashoholic's best friends.


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## chillinn (Dec 17, 2016)

Dr. Mario said:


> Of course, protected Lithium-ion batteries do still have their place, especially in the multi-celled flashlight which you do need a lot of redundancy to ensure it stay safe - most circuit breakers trip if there is inconsistency in current consumption.



Only just within the last few days I have been introduced to the idea that the protection strip can fail, at times spectacularly, for whatever reason. Safety redundancy appears on its face to benefit all. But if you consider that the more complexity you add to something, the more points of failure exist, the necessity of safety redundancy is diminished. 

I'm not disagreeing just to disagree, but hopefully in dissent we all might better have an overall view of the facts and the truth (which is philosophically (i.e. epistemologically and metaphysically) unknowable, unattainable... we can only reduce the margin of error) , and then better base our own conclusions on what is necessary or ideal for our individual purposes.


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## seery (Dec 17, 2016)

A few months ago we switched to all unprotected cells (GA/VTC6/30Q) in our K60's and K70's.

Nothing more than I just feel more confident in them vs. the protected KeepPowers and Evva's we had been using.


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## Dr. Mario (Dec 17, 2016)

chillinn said:


> Only just within the last few days I have been introduced to the idea that the protection strip can fail, at times spectacularly, for whatever reason. Safety redundancy appears on its face to benefit all. But if you consider that the more complexity you add to something, the more points of failure exist, the necessity of safety redundancy is diminished.



I totally agree.

That's why I prefer to use unprotected Lithium-ion batteries nowadays as the low voltage cutout circuit breaker function is adequately provided by the software nowadays on 7135 LDO or buck / boost converter LED drivers which are now managed by the microcontroller chips.

Low voltage cutout in the provided circuit breaker board inside the protected Lithium-ion batteries are considered the last resort (which is to cut off at 2.5 Volts) which shouldn't be abused unless you can confirm it cuts off at 3.0 - 3.5 Volts. As for amperage rating on the cell, the purpose of high drain cell is effectively defeated by the circuit breaker board which usually trip way below what the cell is capable of.

So it's a no-go on the pocket rocket flashlights which may drain way above the cutoff current settings (usually at the current rating significant enough to obliterate the SMD components in the circuit breaker board - about 10 Amps or more, from the trends of the pocket rockets discussed hereon).

Hence, for the TLR version: Not worth using protected Lithium-ion batteries in intelligent LED flashlight which usually has low voltage cutout protection and in the pocket rockets.

P.S. We now need to include multi-voltage, multi-cell circuit breaker function into the multi-celled flashlight as there is enough space on the LED driver board, and potentially enough space on the microcontroller chip's flash memory. That way we can eliminate a few remaining problems with the sketchy protected Lithium-ion batteries.


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## vicv (Dec 17, 2016)

Dr. Mario said:


> I totally agree.
> 
> That's why I prefer to use unprotected Lithium-ion batteries nowadays as the low voltage cutout circuit breaker function is adequately provided by the software nowadays on 7135 LDO or buck / boost converter LED drivers which are now managed by the microcontroller chips.
> 
> ...



How is the driver going to know individual cell voltages without it being a proprietary pack? You need wires going to each individual cell in that case. Not possible in a tubular flashlight


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## Dr. Mario (Dec 17, 2016)

It don't have to. The trick is using voltage dividers feeding into the microcontroller ADC (analog to digital converter) and work with the cell voltage values from both ADC and settings in the software. It's usually what some cheap LED drivers like Nanjg do to ensure it don't go out of check.

As for multi-celled circuit breaker, there's no need for proprietary battery either, you just read individual cell's voltage and make a decision to continue or either cut off or dim down and flash a warning strobe (red LED in the button) to indicate the problem with batteries, while also buying you a bit time with dim light so you can swap out the batteries after finding alternative sources of illumination.

Microcontrollers nowadays have several on-die ADCs which is useful in several type of sensor applications - you can also substitute that with a Lithium-ion battery protection chip and latch onto its I2C / SPI bus to figure out what's going on. That's the beauty of software, it allows you to do that cheaply (even to the point it make some proprietary chips totally unnecessary).

As for tubular flashlight (can style), there is usually room for several wires. There's no excuse in that because of the volatile nature of the Lithium-ion batteries - it's best to continuously monitor the cells to be sure, as I don't think some folks would ever bother to check any cells before chucking them in. It's either the flashlight shutting down safely or it explode taking its user with it. It's also further proven by rashes of news concerning exploding multi-celled vapers.


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## vicv (Dec 17, 2016)

But how are you going to load cells into a flashlight from either the tail or the head when there's a tab or something in between the cells? Load one cell from each end? That's rather inconvenient. I like your idea. Like lipo packs where there's a balance cable. That's a premade multi cell pack though. Implementing that idea into a tubular flashlight that takes cylindrical user replaceable cells just isn't feasible. Also cells going out of balance are not going to explode. If there's that much of an imbalance to really cause problems the lower capacity cell will just be dead. And the charger will not charge it if it's too low or if the polarity has been reversed


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## Dr. Mario (Dec 17, 2016)

Spring-loaded pins for voltage measurement taps and retainer pins on the printed circuit board on the battery carrier so it don't rotate when you twist the cap back in. If you have seen the soda can style quad-celled flashlight, you would know what I mean - some has battery carrier.

I would do this on my soda can flashlight (with a custom LED driver board) because I simply can't trust that the batteries won't go out of balance - it's like building a house without the foundation and expecting it not to fall apart.


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## vicv (Dec 17, 2016)

Ok. Spring loaded pins in the tube? That would be very difficult to manufacture inside the tube of the light. And I'm not talking about lights with battery carriers. I'm just talking a simple tube with a switch at the tail and a head at the other end. I think you're over worried about cell balance though. I use almost exclusively Incan lights. Some draw a lot of power. Never a problem of cell balance. A tenth of a volt or so doesn't matter. And I don't even have low voltage protection. With incans it's easier because I can see when the batts are dead. If an led light takes 2x18650 and lvp of 6v. If one cell is 2.9V and the other is 3.1V it's still not a problem


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## StorminMatt (Dec 18, 2016)

vicv said:


> If an led light takes 2x18650 and lvp of 6v. If one cell is 2.9V and the other is 3.1V it's still not a problem



And THIS is why I don't worry about running unprotected cells in series. If you take a worst case scenario where you run one cell down to 2.5V, the other would have to be at 3.5V when a 6V low voltage protection or warning kicks in. Unless you do something grossly negligent like not fully charging your batteries before use, use batteries of different capacity, or run a new cell with one that is a few years old, this is simply NOT going to happen. Even if the cells are not perfectly matched in terms of age and cycles, getting a voltage diference of more than .2-.3V is pretty unlikely so long as you stick with quality cells and age/cycles are not GROSSLY different. And even if there is no low voltage protection and/or warning of any kind, it is really just a matter of knowing your runtime and giving yourself some wiggle room. For instance, if you have a two cell light that can run two hours on two 18650s, you really have NOTHING to worry about so long as you run your light for, say, an hour and a half and always fully charge both batteries before use. You just might wnat to periodically do a runtime test to make sure that you adjust your runtime expectations (or relegate the cells to single cell use) as the cells age.


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## vadimax (Dec 18, 2016)

Tough men use unprotected only! Hardcore rocks  But not stupidity. DMM is a must.

Yesterday have checked more than a year old Thrunite TN32. All three unprotected 18650 cells happened to be exactly the same voltage with mV precision.


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## dc38 (Dec 18, 2016)

vadimax said:


> Tough men use unprotected only! Hardcore rocks  But not stupidity. DMM is a must.
> 
> Yesterday have checked more than a year old Thrunite TN32. All three unprotected 18650 cells happened to be exactly the same voltage with mV precision.



Impressive, as I was sure the tn32 runs in series. Was that resting voltage?


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## vadimax (Dec 18, 2016)

dc38 said:


> Impressive, as I was sure the tn32 runs in series. Was that resting voltage?



That was a bit depleted voltage. Were charged, got some use, then I did a check -- all three were at 4.07V. The case showed 12.21V accordingly.


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## stephenk (Dec 18, 2016)

There are a few things that can catch people out in series lights. Parasitic drain running cells below 2.5V, and mixing up full and empty cells causing reverse charging (there is a thread in this forum of a serious li-ion explosion caused by this). As far as I'm aware, a good protection circuit should prevent both. Sadly, humans are humans, and even the best of us can make mistakes. I've started using unprotected cells in single cell lights with LVP, but still prefer to use protected in series lights (even though I've never done anything that would require the protection circuit to kick in).


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## vadimax (Dec 18, 2016)

A protected cell is like a gun you are unable to shoot your own foot , but cannot kill a dog that already has clung into your leg. I prefer responsibility because it leaves me an option to deplete batteries dry in SNAFU situation and not to find myself in position of unexpected darkness (protection kicked in) and forced battery change.


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## Gauss163 (Dec 18, 2016)

Keep in mind that protected cells protect against not only user error, but also against faulty devices, e.g. a defective charger that charges to too high voltage or at too high current. Even if you are very knowledgeable about safety and also highly-disciplined enough to rigidly follow safety rules (a rare combination), you have little if any control over device faults. That's one reason why it's worthwhile having multiple levels of fault protection.


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## vadimax (Dec 18, 2016)

Well, may be. But the only experience I had with protected cells so far -- is kicking in current protection of Olight 16340 cell inside Olight S1 Ti


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## StorminMatt (Dec 18, 2016)

stephenk said:


> There are a few things that can catch people out in series lights. Parasitic drain running cells below 2.5V, and mixing up full and empty cells causing reverse charging (there is a thread in this forum of a serious li-ion explosion caused by this).



That's why you (1) don't store your cells in your light (unless the light does NOT use an electronic switch OR you can lock out the light), and (2) ALWAYS fully charge your cells before using the light.


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## stephenk (Dec 18, 2016)

StorminMatt said:


> That's why you (1) don't store your cells in your light (unless the light does NOT use an electronic switch OR you can lock out the light), and (2) ALWAYS fully charge your cells before using the light.


That is true, but sadly not everyone has that common sense.


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

I have a habit of holding a small flashlight in my mouth leaving my hands free to work, I use an protected cell in that case  or an nihm flashlight.

John.


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## stephenk (Dec 19, 2016)

TinderBox (UK) said:


> I have a habit of holding a small flashlight in my mouth leaving my hands free to work, I use an protected cell in that case  or an nihm flashlight.
> 
> John.


Maybe you need a headlamp?


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## Dr. Mario (Dec 19, 2016)

As for the chargers, I usually check the chargers, loaded or unloaded, with the DMM before I can truly trust them. Built-in protection is good to have, but as everyone knows, it's both a blessing and a curse.

I usually follow very strict rules of Lithium-ion battery handling (ie. doing homework before buying the particular batteries for whatever they will be used in - in term of peak short-circuit amperage rating which is occasionally important in pocket rockets, and capacity, down to charging them with proper chargers, all from cradle to grave).

If you can properly follow the safety rules, there's little need for the built-in circuit breaker for overall usage. Still, good point on LED driver failure mode, which I would think it is a good idea to have the built-in circuit breaker board inside the protected battery - up to a point there's a big difference between the nuisance trip or legit short-circuit trip in term of end LED current consumption (some LEDs like Nichia 219 / 319 LEDs can easily survive 6 Amps current no problem) and the LED driver current consumption as well as circuitry topology (switchmode or linear regulation).


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## Gauss163 (Dec 19, 2016)

Dr. Mario said:


> [..] If you can properly follow the safety rules, there's little need for the built-in circuit breaker for overall usage [..] .



As I emphasized above, even if you could unerringly, robotically follow safety rules, that doesn't eliminate the need for protection circuitry, because it protects not only against user errors but also against _device _failures, such as chargers that have gone awry, or were improperly designed etc. 

As for following safety rules, even experts make mistakes, e.g. the hobby shop owner who's shop burnt down when he stepped out for 10 minutes while leaving some packs charging. The problem here is that it's easy to get too comfortable, thinking, ah, I've charged hundreds of Li-ion batteries and never had a problem, so it should be ok to step far away from the charger for 15 minutes to do xyz. But if you want to be safe, you should never do that, even if 99% of the time you can get away with it.


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## Dr. Mario (Dec 19, 2016)

Still, you have to always allow redundancy - if you don't think to follow strict rules, expect trouble. It's not your father's Nickel Cadmium battery, that thing pack a punch so you have to always be sure, even though some Lithium-ion battery types allow rooms for some mistake, you certainly won't with classic Lithium Cobalt Oxide cells (which is why I don't handle Li : CoO2 cells anymore, they easily overheat as much as you sneeze at them).

Robotically? Not so, as there are so much warning points in the datasheets especially for the Sony 18650 cells that you have to take that very seriously.


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## Dr. Mario (Dec 19, 2016)

Also, most newer 18650 cells are now of Lithium Polymer types, so extra cares have to be heeded - personally I prefer that over handling the pouch cells as it's easy to blow one of them up even from slightly bending it due to the pouch cell being so soft. Metal cans mitigate the risks somewhat, so you're left to deal with electrical details like LVP (low voltage protection) and charging process.


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## Gauss163 (Dec 19, 2016)

Dr. Mario said:


> Still, you have to always allow redundancy - if you don't think to follow strict rules, expect trouble [...e]



Yes, that's exactly the point I was making above. Maybe your earlier statement ("if you can properly follow the safety rules, there's little need for the built-in circuit breaker for overall usage") meant something different that what I thought. I interpreted it as implying that there was no need for protection circuitry (e.g.protected cells) if one can follow safety rules.


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## Dr. Mario (Dec 19, 2016)

I suppose. There's some redundancy in the LED drivers nowadays and you can ask to have desired voltage cutout put in for extra fees anyways. We're now seeing less and less of the "dumb" LED drivers (not defined by firmware as such) though, as microcontrollers now only cost a couple of changes.

I would still use protected Lithium-ion batteries in multi-celled setup as we would never know, in term of voltage balance of entire cells under load. I never find protected Lithium-ion cell necessary in the single-celled flashlight anyhow, and it's up to the others to interprete. (One exception, however, is that I would use protected Lithium-ion battery at first in new, stock flashlight like Olight or four-sevens for example, so I can be sure the software-defined LVP is working as intended, without tripping the circuit breaker inside the protected Lithium-ion battery before I decide to chuck unprotected Lithium-ion battery in it the next time - and all my DIY flashlights I assembled trip out at 3.0 Volts.)

For those new to Lithium-ion batteries, I technically recommend the protected Lithium-ion batteries until they gain enough experience and knowledge to use the unprotected Lithium-ion batteries in their flashlights safely. It's like the gun, which you have to have knowledge to use it safely; it can either be your friend or your enemy.


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## Tachead (Dec 19, 2016)

psychbeat said:


> On both occasions the thin flat wire shorted to the metal case. Once, on the edge near the positive end and the other near the neg end when the cell was dropped.
> 
> When this happens you need to watch out as the flat wire heats up quickly and will melt the wrapper.
> Both of the cells were fine after I removed the PCB and rewrapped. In fact, I'm still using them regularly.
> ...



Many new high quality protected cells no longer use the thin metal strip down the side and have riveted steel enclosures to protect the PCB. Some can also handle 10 amps continuous draw now and have a full 1 year warranty as well. Protected cells have advanced along with cells in general. It's still hard to beat the price of unprotected though.


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## Dr. Mario (Dec 20, 2016)

I certainly hope so, as it's hard to tell under the wrap.


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## fivemega (Jul 19, 2017)

Why Use Unprotected While *[SIZE=+2]Protected Works Fine?[/SIZE]*


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## Ozythemandias (Jul 19, 2017)

fivemega said:


> Why Use Unprotected While *[SIZE=+2]Protected Works Fine?[/SIZE]*



I saw this on the home page in huge red letters and actually laughed, kudos.


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## vadimax (Jul 19, 2017)

fivemega said:


> Why Use Unprotected While *[SIZE=+2]Protected Works Fine?[/SIZE]*



Because they don't. While flashlight vendors compete for compactness more and more lights fit protected cells poorly (springs overstressed or even deform a battery when closed) or do not fit them at all. Often current protection kicks in too early, disabling a high drain light, when unprotected cell of the same vendor works just fine not even warming up under load.


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## eh4 (Jul 20, 2017)

Regarding the Darwin Award and Intelligent User comments, would you hand a light with unprotected batteries to a child, or to someone who was an otherwise responsible adult but wasn't into geeking out on electronics and battery chemistry? 

- Say for instance in the unlikely situation where the light was a tool that needed to work without being a distraction regarding its own special needs.


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## ChrisGarrett (Jul 20, 2017)

eh4 said:


> Regarding the Darwin Award and Intelligent User comments, would you hand a light with unprotected batteries to a child, or to someone who was an otherwise responsible adult but wasn't into geeking out on electronics and battery chemistry?
> 
> - Say for instance in the unlikely situation where the light was a tool that needed to work without being a distraction regarding its own special needs.



To answer your question, I wouldn't hand a flashlight with a naked li-ion cell to anybody who wasn't versed in the use of such, but I would probably lend a light that ran off of AAs to a neighbor, or one that used say...D batteries.

I have a few lights that fit into the latter category, for such an event, but as a rule, I don't any longer buy protected cells for my personal use.

Chris


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## eh4 (Jul 20, 2017)

... ;-)


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## markr6 (Jul 20, 2017)

Why Use Unprotected While Protected Works Fine?

It feels natural!


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## ven (Jul 20, 2017)

For the 1st time in ages(years) i have bought 2 button top protected keeppower 16650's. The reason simply for a few extra mm in length for some lower powered drop ins(standard surefire hosts). I have and still do use some magnets, these are on the standard flat top sanyo 16650 4.35v cells in standard hosts. But for work, the highest i will use is around 1.5a iirc for the oveready 219b mule(around 300lm which can be a little too bright sometimes). Even the sportac triple sees 20% mode 90% of the time in work.


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## fivemega (Jul 20, 2017)

vadimax said:


> Often current protection kicks in too early,


*If current protection kicks in too early, then it does not work fine.
The question is clearly mentioned in post #1 and #62

Just imagine you have two identical flashlight of same make and model, one has protected and second has unprotected and they both work same way and you can't tell the difference, which one you prefer and why? *
--------


ChrisGarrett said:


> I don't any longer buy protected cells for my personal use.


*So your unprotected cells are for your own use only.
I can understand that and 100% acceptable.*


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## StorminMatt (Jul 23, 2017)

Why don't I use protected cells? There are several reasons:

1. SELECTION - Only a few different cells are available as protected cells. For obvious reasons, these are typically low current, high capacity cells like the NCR18650B or NCR18650GA. These may not be bad cells. But they are limiting, even in lights that don't draw HUGE current. For instance, high current cells like the VTC6 now offer virtually the same capacity as the old NCR18650B with better voltage. Also, cells other than these may be just as good, but available at a lower price because of their obscurity (think Samsung 35E vs NCR18650B or MJ1). Using unprotected cells allows you to choose which cells you want to use rather than being forced to use only those available as protected cells.

2. PRICE - Of course, you already knew this one. Unprotected cells are quite a bit less expensive than protected.

3. FITMENT - We all know about length issues with protected cells. We also know that some newer lights (like Zebralights and the Astrolux quads) can't fit protected cells. Protected cells are also generalky thicker, which can cause fitment issues as well.

4. SAFER CELLS - True ICR cells are largely a thing of the past. The newer hybrid cells are LOTS safer, so protection circuits just aren't as necessary to keep you safe.

5. PROTECTED LIGHTS - Most quality single cell lights have good onboard overdischarge protection. Overdischarge protection on the cell just isn't needed in this situation.

6. NOT WANTING TO BE LEFT IN THE DARK - Protected cells cut power instantaneously when voltage is too low. This can be inconvenient at best, or dangerous at worst. Protected lights generally step down before finally cutting power, allowing you to have SOME light. So you won't trip and twist your ankle on a rock because everything just went dark.

7. BETTER VOLTAGE - Protection circuits generally eat up a tenth or two of a volt. This may not seem like much. But it can make a difference, particularly at hugher brightness levels. It can also reduce runtime somewhat since the voltage threshold for a light's built-in protection is reached sooner. Voltage can also be better since using unprotected cells allows the use of higher current cells (which maintain voltage better).

8. HIGHER CURRENT - There are two reasons for this. First, high current cells are generally unprotected. Secondly, thr protection circuit will often kick in even below the rated current of a cell. Therefore, unprotected cells will work better in the many lights available that can draw higher currents.

9. SIMPLICITY/RUGGEDNESS - There is one less thing to go bad in an unprotected cell. Protection circuits donoccasionally fail. And a drop where the cell lands on the PCB has the potential to damage it. When a protection circuit goes bad, the cell is useless. Sure, you can always pull the circuit and use it as an unprotected cell. But you may be in a situation where you don't have a wrapper to pull this off (like out hiking). And, of course, if you are a member of the 'protected cells ONLY' brigade, this is a no-no anyway.

10. SAFETY - Yes, I said safety. Most protected cells still have the strip on the side from the positive terminal to the PCB at the negative side. As you probably know, damage to the insulating layer can cause a dead short. Having this kind of damage is NOT so far-fetched, as a good drop on sharp rocks could do it. It is also possible for a drop where the the cell lands on the PCB itself to damage the PCB in such a way that it shorts out. In addition to the issue to physical damage, there is the issue of questionable suppliers. Low quality protection circuits or the absence of protection altogether (which may cause the user to be lax since fhey think the cell is protected) could cause problems as well.

11. WIDE AVAILABILITY OF GOOD CHARGERS - Quality chargers these days do a GREAT job of properly terminating the charge. If you stay away from cheap junk chargers, there just isn't much to worry about as far as chargers overcharging batteries.


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## archimedes (Jul 23, 2017)

StorminMatt said:


> Why don't I use protected cells? There are several reasons ....



Although there are certain situations I still prefer protected cells (or unprotected cells, for that matter) ... outstanding summary and post, Matt, thanks[emoji106]


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## markr6 (Jul 24, 2017)

archimedes said:


> outstanding summary and post, Matt, thanks[emoji106]



Yes, very nice! :twothumbs

I only use protected in my Nitecore EC4SW just because it came with them. But it doesn't matter what you use in that light...it will suck them dry in a couple weeks just sitting off!! Typical Nitecore.


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## ven (Jul 25, 2017)

Excellent post Matt, that sums up my thoughts and reasons why I myself mainly use high drain cells.


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## fivemega (Jun 8, 2018)

*Anyone else?

Assuming protected cell works fine (without problem) in a specific flashlight, why do you use unprotected in same flashlight?*


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## id30209 (Jun 8, 2018)

I'm using protected most of the time while unprotected in flashlights which requires 5-10A but have driver set with Vlow, not allowing to go overdischarged. Sometimes using unprotected in the same flashlight for a test to see how the same flashlight behave. 
Btw, good point Matt.


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## vadimax (Jun 8, 2018)

In most situations I avoid protected cells. Right to that moment I had only issues with them when protection kicks in because the light wants more current during its normal operation (the battery discharges, voltage goes down, regulated driver tries to pull more A —> hello darkness).

Finally two of them have found their real application — they go to a Tecsun S-8800e that goes to my wife  Did that because of two points: I have no idea about Tecsun’s built in charger quality; this radio battery nests are so long that some NCR18650GAs barely compress the “-“ spring making me bother about poor contact.


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## peter yetman (Jun 8, 2018)

I used to puirchase only protected cells until three or four PCBs failed in about a month. What with that and being left in the dark, I'm all IMR and INR now.
I take care of my cells and use decent chargers, I see no problem with this.

May I ask a question? If I lend a light to someone who is uninitiated, how can they do themselves harm with an unprotected cell in a light without LVP? I'm not lending them a charger.
If they run the cell past safe discharge, the only way to cause a fire is if i recharge it.
Am I right or wrong, please?
P


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## fivemega (Jun 9, 2018)

vadimax said:


> I had only issues with them when protection kicks in because the light wants more current during its normal operation (the battery discharges, voltage goes down, regulated driver tries to pull more A —> hello darkness).


*Seems like you never pay attention to question. If protected cell can't provide current demand, then you can't use it. Then we don't have a question. You have to find another solution. You have to use unprotected or even IMR. We all understand that and we are assuming a protected cell works [SIZE=+5]FINE[/SIZE] (without any problem) in any specific flashlight. In this case, why use unprotected?
Please see post #70 and #75*
===


peter yetman said:


> I used to puirchase only protected cells until three or four PCBs failed in about a month. What with that and being left in the dark, I'm all IMR and INR now.


*If a PCB failed in a cell, you will throw away $10~15 and get a new one. Can you do it if you or your loved one injured from unprotected?
BTW, you can always carry some extra fully recharged cell if you think you may need them.*



peter yetman said:


> I take care of my cells and use decent chargers, I see no problem with this.


*There is no problem with this but is there any problem with a little extra care?*


peter yetman said:


> If I lend a light to someone who is uninitiated, how can they do themselves harm with an unprotected cell in a light without LVP? If they run the cell past safe discharge, the only way to cause a fire is if i recharge it.


*If a protected cell has electrical short circuit, there is a chance that PBC block the current flow but the chance for unprotected is ZERO. In this case, BOOM
Not worth it.*


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## WalkIntoTheLight (Jun 9, 2018)

Protected cells are for little girls. Be a man! :rock:


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## fivemega (Jun 9, 2018)

WalkIntoTheLight said:


> Protected cells are for little girls. Be a man! :rock:



*Yes, be a man but smart man and use protected.
Nobody can tell voltage of battery while flashlight is switched on and running unless a voltmeter is connected to battery all the time for monitoring battery voltage. A protected cell will do that and automatically shuts down to save the cell from over discharging.
So no matter if you are a little girl or big man. Be smart.*


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## hiuintahs (Jun 10, 2018)

For the most part I don't us protected. If I need a button top battery for a flashlight, then its protected. If I do a run time test, then its a protected cell. If I give a 18650 light to a relative or friend that I don't think will pay attention to the logistics of lithium ion, then I make sure its protected cell. Most of my batteries are unprotected. My favorite cell right now is the unprotected 3500mAh NCR18650GA.


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## DayofReckoning (Jun 10, 2018)

Well, I am certainly limited on my battery knowledge, but I can think of one scenario where running unprotected cells could have an advantage.

When running certain incandescent setups, protected cells may cause one to have to double/triple tap the switch to order to fire up the bulb. My understanding is unprotected cells would not require this.


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## fivemega (Jun 10, 2018)

DayofReckoning said:


> running unprotected cells could have an advantage.


*An advantage but three disadvantages.*
*


fivemega said:



Why Use Unprotected While Protected Works [size=+2]Fine[/size]?

Click to expand...

*


DayofReckoning said:


> When running certain incandescent setups, protected cells may cause one to have to double/triple tap the switch to order to fire up the bulb.


*This situation is out of our discussion. Double or triple tap is not [SIZE=+2]FINE[/SIZE].*


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## vadimax (Jun 11, 2018)

If protected and unprotected battery work fine in some application there is still a difference: the protection circuit serves no other function than increasing the entropy of the universe — it generates useless heat  That energy could have been used to produce light.


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## markr6 (Jun 11, 2018)

I use unprotected. I never wore a helmet on my bike when I was a kid. I regularly drive 5mph over the limit. I eat donuts. I won't be on this planet for long!


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## vadimax (Jun 11, 2018)

markr6 said:


> I use unprotected. I never wore a helmet on my bike when I was a kid. I regularly drive 5mph over the limit. I eat donuts. I won't be on this planet for long!



You forgot to mention business that sounds similar to “six”


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## id30209 (Jun 11, 2018)

Guys i belive it's fun to you but there's a reason why protected and unprotected cells are made and for what use. Using blindly only one type of batteries isn't good for your wallet sometimes.


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## vadimax (Jun 11, 2018)

No one denies protected cells entirely. In situations with too many variables they are good. But we pretend to understand what we are doing. And in this case protection circuit plays the only function of a useless electric ballast that adds to the system complexity and reduces reliability via adding one more point of possible failure.


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## xxo (Jun 11, 2018)

All else being equal, protected cells are:

- More expensive.

- Slightly less efficient.

- Have extra components that can fail, or even potentially short out if damaged.

I think protected cells make a lot of sense in lights without a dependable low Voltage cut off. But for a quality light with good low Voltage protection (and over Voltage protection if the cells are designed to charge inside the light) built in, I don't see the advantage of protected cells. 


I would turn the question around: Why use protected cells in a light with low Voltage protection?


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## Gauss163 (Jun 11, 2018)

id30209 said:


> [...] one type of batteries isn't good for your wallet sometimes.



So, unprotected cells are pants-on-fire risks, but protected cells are wallet-on-fire risks? Please give a link to some YouTube wallet-on-fire videos! Vaper pants-on-fire are passe by now.

More seriously, it is difficult to give a good _general _answer to such questions since the correct choice is highly context dependent (on device, quality of cell and protection circuit, ability of user to rigorously follow safety protocols, etc).


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## magellan (Jun 11, 2018)

<<Vaper pants-on-fire are passe by now.>>

LOL

I recall one story of a vaper who had a pretty severe accident. He was running one of those custom sub-ohm hot-wire mech mods, as they call them, and the battery exploded. Burned his nose and face, knocked out a couple of teeth, and it was even reported that his jaw was fractured. Fortunately those kinds of serious incidents are rare.


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## ven (Jun 11, 2018)

Vaping can get crazy, some use such low ohm coils in their builds..............basically they are shorting the battery/s out. Just checked now and my mod is using 6.8a through 2x 20700 cells(not much load for 3s or so at a time). I dont get the crazy build, have tried 80w even up to 120w and the tank is hot to touch in a vape ................each to their own.

Question for using unprotected instead of protected when protected works fine is really down to the user. Having extra protection always makes sense if available to the end user. Now i have seen where protected cells have shorted through the strip on the side getting caught. So positives, over and under voltage protection is the usual, too much load trips as well(say 5a or 8a etc variable). Negatives, potential slight parasitic drain, something else in the equation to fail(trip in the field and no way of resetting or having no back up..........). Cell length, some lights are not 69/70mm+ friendly. Cost is maybe another factor, 10 protected cells could be $30 or so ,more over unprotected(just an example). 

Now some of my lights(certainly 16650) have PCB's, this is more for length with the extra few mm making better contact. Now these lights are sportac triples and OR mule which dont ask more than 3a. Also being in work, its a little more protection. My sons lights have PCB's, now i take care of the charging etc. If anything fails(like me!) there is a little protection there for a cell draining(say Callum left a light on by mistake........it happens, even us adults can do it time to time. 

I am a little OCD with my charging and voltages, every cell gets checked in a charger to mentally note what i have used. If i use a light in work, the cell gets topped up at the end of the day(or 1st thing next morning) ready to go again. Only times i dont top off is when the use has only been a few mins-20m. I dont recall ever a cell getting bellow 3.5v in work, mostly 3.8v and up. 

At home i use some more demanding lights, or ones designed around using high drain cells(where even button top unprotected wont fit!). So flat top high drain cells, i make sure my source for these cells is reputable. I only use said cells i know and in good condition, noting the IR each time i top off. Any damage to wraps get replaced there and then.............If high drain cells are required, i make sure their spec is above the required, i dont push any cells above and beyond their specs. Multi cell lights are matched the best i can, again taking note of voltages after use. If one cell is weak(lower V ), then a new batch of 4 would get used, others used solely in single cell lights. 

Protected or unprotected, all should be treated the same, regardless of any protection.........with respect and without abuse. Protection may give some a false sense of safety, thinking they can get away with more abuse/neglect.............i am sure it happens. Maybe human nature................just a thought.

Cheers.


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## Gauss163 (Jun 11, 2018)

magellan said:


> I recall one story of a vaper who had a pretty severe accident [...] Burned his nose and face, knocked out a couple of teeth, and it was even reported that his jaw was fractured.



I reported that to the smoke-and-fire subforum a couple years ago (photo below). Still waiting for a good wallet-on-(ultra)fire specimen for the zoo. Aha, no one has patented the idea of a wallet with 18650 storage compartment. I just inquired about such on Alibaba. So it shouldn't be long before they pop up all over eBay. Stock up on popcorn.



magellan said:


> Fortunately those kinds of serious incidents are rare.



Alas, not as rare as they could be with proper safety training. Of course said injuries could have been avoided by using the appropriate Ultrafire endorsed vaping gear, e.g. their patented 10,000 °C mask below (highly recommend when vaping with their 10,000 mAh cells). Vape _ultra_-safely folks.


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## WalkIntoTheLight (Jun 11, 2018)

xxo said:


> All else being equal, protected cells are:
> 
> - More expensive.
> 
> ...



Even if your light doesn't have LVP, you're unlikely to drain an unprotected cell unless you forget the light is on and leave it for a few days. The emitter will cut-out at about 3v, and you'll get plenty of warning before that because your light will no longer get higher modes. The driver likely doesn't use much power when the LED is out, but you'll still want to turn it off for real before waiting too long.

The exception is a light with a boost-driver, but I don't know of any brand that has a boost driver but no LVP.

I never understood some flashaholics insistence on protection circuits. We all know proper battery care. Besides, a protection circuit won't save you from damage or internal shorts, which is the most dangerous kind of random-venting scenarios.


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## Gauss163 (Jun 11, 2018)

ven said:


> [...] Having extra protection always makes sense if available to the end user. Now i have seen where protected cells have shorted through the strip on the side getting caught [...]



Yes, that's one of the problems with some common single-cell protection designs. The (positive) metal strip running down the side of the can is separated from the negative can only by thin tape. This increases by an order of magnitude the surface area where shorts can be induced by small metallic objects. In that sense they are less safe that unprotected cells. More generally the protection itself is poorly (mechanically) protected, so e.g. a dropped cell could cause significant damage to the protection circuit, possibly disabling some of its protection mechanisms.


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## ven (Jun 11, 2018)

Gauss163 said:


> Yes, that's one of the problems with some common single-cell protection designs. The (positive) metal strip running down the side of the can is separated from the negative can only by thin tape. This increases by an order of magnitude the surface area where shorts can be induced by small metallic objects. In that sense they are less safe that unprotected cells. More generally the protection itself is poorly (mechanically) protected, so e.g. a dropped cell could cause significant damage to the protection circuit, possibly disabling some of its protection mechanisms.



Thank you for confirming, i was sure i had seen(or read) reports of such incidents. Fenix(off the top of my head) seem to have come up with some clever ideas regarding PCB's with their protection. Going beyond min/max V protection. Over heat protection and also in the structural design. Maybe soon we will have high drain cells with protection, yet not too much added in length to give more flexibility in flashlights(fussy ones that like shorter cells for example).


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## magellan (Jun 11, 2018)

Gauss163 said:


> I reported that to the smoke-and-fire subforum a couple years ago (photo below). Still waiting for a good wallet-on-(ultra)fire specimen for the zoo. Aha, no one has patented the idea of a wallet with 18650 storage compartment. I just inquired about such on Alibaba. So it shouldn't be long before they pop up all over eBay. Stock up on popcorn.
> 
> 
> 
> Alas, not as rare as they could be with proper safety training. Of course said injuries could have been avoided by using the appropriate Ultrafire endorsed vaping gear, e.g. their patented 10,000 °C mask below (highly recommend when vaping with their 10,000 mAh cells). Vape _ultra_-safely folks.




Wow. That’s a pretty dramatic photo. Thanks for reposting that along with your post.

I missed your post but encountered the story on a vape website when I was trying to learn more about these vaping devices. (Glad I remembered the details right ;-)). I don’t vape myself, but the vapers were pushing the limits and I was following their adventures, so to speak, because I was curious how this would play out. It’s one thing to be holding a flashlight in your hand, but it’s another thing to be using a device that’s right in your face.


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## magellan (Jun 11, 2018)

ven said:


> Vaping can get crazy, some use such low ohm coils in their builds..............basically they are shorting the battery/s out. Just checked now and my mod is using 6.8a through 2x 20700 cells(not much load for 3s or so at a time). I dont get the crazy build, have tried 80w even up to 120w and the tank is hot to touch in a vape ................each to their own.
> 
> Question for using unprotected instead of protected when protected works fine is really down to the user. Having extra protection always makes sense if available to the end user. Now i have seen where protected cells have shorted through the strip on the side getting caught. So positives, over and under voltage protection is the usual, too much load trips as well(say 5a or 8a etc variable). Negatives, potential slight parasitic drain, something else in the equation to fail(trip in the field and no way of resetting or having no back up..........). Cell length, some lights are not 69/70mm+ friendly. Cost is maybe another factor, 10 protected cells could be $30 or so ,more over unprotected(just an example).
> 
> ...



Very informative. Thanks for the detailed post on your experiences as I’ve been following the vaping area a bit although I don’t vape myself.


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## ven (Jun 12, 2018)

Thank you Magellan


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## magellan (Jun 12, 2018)

You’re welcome!


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## Newlumen (Jun 13, 2018)

Because protected cell are expensive than unprotected... i strictly use an unprotected cells whenever i can.


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## MrAl (Jun 14, 2018)

Hello there,

I dont know if this has been said or not yet but, some things will simply NOT run on protected cells because the protection circuit does not go up high enough to allow the proper current to flow. I dont think there are any protection circuits that go up to 30 amps for example, but i know they do go up to 10 amps. If you have a light that needs 12 amps, then you cant use a 10 amp battery can you, so you need to go to an 'unprotected' type of cell.

I only have one light like this an i take special precautions when using it and when charging the batteries. For example, when i turn the light 'off' i also rotate the body of the light by 1/2 to 1 full turn. That disconnects the battery cells from the light electronics. So i do not depends on the circuit to keep the light off and that is because the circuit to turn the light on and off is always active even with the light off because they use a momentary push button switch to turn the light on. But even if that wasnt the case, i still like knowing that my cells are completely disconnected from the circuit when i turn off.

I also keep a close eye on the charge process, never leaving the area even for a minute when they are on charge, but then again i do that with all of my Li-ion cells. I also have a chemical fire extinguisher within arms reach ready for any emergency situation.

But to the point of the thread, the main reason that i know of for using unprotected cells is that you have a device that simply will not run on protected cells so you must purchase unprotected cells and use them. Otherwise, you can not use that device because it will keep tripping the protection circuit unless maybe you have a "low" setting you can try.


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## lion504 (Jun 14, 2018)

I use unprotected cells when I know the light has LVP. I have an XTAR charger, so good there too.

My question is about Malkoff P60 drop-ins. Gene's web page says "This dropin was primarily designed for use with a single Li-ion protected rechargeable cell." 
I asked him whether it was Ok to use unprotected cells and his response was "It [the unprotected cell] won't harm the drop-in." LOL!!! I was more worried about the humans using the drop-in...

Anyways, can anyone confirm if Malkoff drop-ins have LVP, so safe to use unprotected? I can't find it on his website... Thanks.


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## archimedes (Jun 14, 2018)

lion504 said:


> ....
> Anyways, can anyone confirm if Malkoff drop-ins have LVP, so safe to use unprotected? I can't find it on his website... Thanks.



No, not as such.


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## fivemega (Jun 14, 2018)

Newlumen said:


> Because protected cell are expensive than unprotected...


*So you don't even value your own safety for $2 extra ???*
===============


MrAl said:


> some things will simply NOT run on protected cells because the protection circuit does not go up high enough to allow the proper current to flow.


*Do you think I would call this situation [SIZE=+5]FINE[/SIZE]?
I repeatedly mentioned, [SIZE=+3]IF PROTECTED CELL WORKS FINE[/SIZE]*
==============


lion504 said:


> Gene's web page says "This dropin was primarily designed for use with a single Li-ion protected rechargeable cell."
> I asked him whether it was Ok to use unprotected cells and his response was "It [the unprotected cell] won't harm the drop-in."


*Because his concern is your safety and not the drop in module.
In most cases, drop in can be replaced but human health can not. So your safety is first.*


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## WalkIntoTheLight (Jun 14, 2018)

fivemega said:


> *So you don't even value your own safety for $2 extra ???*
> ===============



Do you drive?


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## lion504 (Jun 14, 2018)

fivemega said:


> *Because his concern is your safety and not the drop in module.
> In most cases, drop in can be replaced but human health can not. So your safety is first.*



I think you make some good points in your posts to this thread. But wouldn't adding LVP to the light (in this case the P60 drop-in) be evidence of caring about the user/customer's safety? 

Is there a good reason why the manufacturer would make the customer to rely on the protection circuit in the battery, which many have pointed out can be unreliable? Other than keeping production costs down?


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## archimedes (Jun 14, 2018)

lion504 said:


> I think you make some good points in your posts to this thread. But wouldn't adding LVP to the light (in this case the P60 drop-in) be evidence of caring about the user/customer's safety? Is there a good reason why the manufacturer would make the customer to rely on the protection circuit in the battery, which many have pointed out can be unreliable? Other than keeping production costs down?



So that you aren't suddenly and unexpectedly without light (running primaries) , which could perhaps be dangerous, in certain situations.

It also allows for more flexibility in power sources, as many of these dropins have a relatively wide voltage range. This allows for some choice in number and type of battery(s) which may be used.

A fixed voltage cutoff would essentially limit the user to a particular specified setup.


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## lion504 (Jun 14, 2018)

Got it. Malkoff drop-ins can use either multiple CR123s (up to 9 volts) or protected Li-Ions. Thanks.


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## MrAl (Jun 15, 2018)

fivemega said:


> *So you don't even value your own safety for $2 extra ???*
> ===============
> 
> *Do you think I would call this situation [SIZE=+5]FINE[/SIZE]?
> ...



Hi,

Well if it works "FINE" then it seems to me it would be your own choice or based on happenstance.
For example, if you did not have any protected cells left and you wanted to change your battery, you'd have to use one of your unprotected cells.
For a risk example, it would depend on if you think the risk of having a strip go up the side of the cell is more risky than using an unprotected cell. I assume you know how to handle unprotected cells here.
For another example, your flashlight has built in limiting.

Probably too many cases to mention here where you might want to use one in place of a protected cell.
Your little brother stole all of your protected cells and you need to go out that very night


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## etc (Jun 28, 2018)

So imagine you are descending down a cave with a headlamp on and a spare light in your backpack along with spare cells.

Suddenly that nice headlight quits. The Li-ion battery is dead and you are plunged into complete darkness.

Now you have to run an emergency battery swap or retrieve the spare light. All while you are hanging on some rock.

Protected Li-ions are not an option for anyone that deals with danger where situations can escalate quickly.

Either primary 123s make tons more sense - they are light and cheap. Or unprotected Li-ions - they store more energy and gradually decline towards oblivion,giving you plenty of time to figure out when to swap.

I can pretty much tell when my lights hit 3.0V and 2.8V just by looking at the output. Over the last decade, since I use the same lights pretty much, I learned to tell when I am close to 2.5V -- and long before I get there. It's not that hard.


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## Gauss163 (Jun 28, 2018)

etc said:


> So imagine you are descending down a cave with a headlamp on and a spare light in your backpack along with spare cells. Suddenly that nice headlight quits. The Li-ion battery is dead and you are plunged into complete darkness. Now you have to run an emergency battery swap or retrieve the spare light. All while you are hanging on some rock. Protected Li-ions are not an option for anyone that deals with danger where situations can escalate quickly [...]



I don't follow your logic. How does the claim in the final sentence follow from what you wrote prior to it?


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## fivemega (Oct 9, 2022)

*Why Use Unprotected While Protected Works Fine ?

What I understand from "works fine" is: doesn't have any of problems mentioned above.

My logic says not to drive a road with little gas and no gas station.

If you really need a light for any task, make sure you have more than double run time of what you need and carry extra battery or backup light.*


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## desert.snake (Oct 9, 2022)

This is all a little strange thread. It is useless to consider abstract cases of using protected or unprotected cells. Too many variables. I would suggest taking a specific flashlight that has certain parameters, for example, SF 6РХ. Take a specific person who uses it, that is, choose a method of use (permanent / short-term / mixed), a charging method (what specific device is used, how often recharging occurs, is there any system in it). It is only later to determine what type of cell is suitable or not suitable for a specific combination of "a specific person + a specific lantern".

Specifically, I moved from the protected elements of the Eagletac 16650 to the unprotected Sony VTC5 and further, further, as the lamps changed. These particular Eagletac have an interesting feature - when they are almost depleted and used with an unregulated lamp, the lamp begins to flicker. I am replacing the battery and the lamp protection has not yet worked. Very good cells for standard lamps.

I had protected IMRs from Olight, their protection circuitry died because I didn't bother to check the SF A2 flashlight, which was drawing more current out of them than they could handle + heated to a very high temperature due to the lamp. I just cut off the protection with a knife and continued to use in other flashlights with power consumption suitable for these batteries.

Now I have a bunch of protected and unprotected 18650s. They all work great, since none of my flashlights draw more current than the rated current of the cells and the flashlight itself gives signals (either by blinking or dimming, or by a fuel gauge, or by a small screen with a voltmeter) that it's time to change the batteries, and not one goes below 3.2-3.4 volts when I replace it with a fresh one.

Times have changed, now there are already protected elements that can withstand 20 A for a long time - Acebeam ARC18650H-310A IMR 18650 3100 mAh 20A 3.7V PCB 4x MOSFET
But I still have a knife to cut off the protection board if she suddenly dies before her cell.


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