Why Use Unprotected While Protected Works Fine?

fivemega

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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.
 

Lexel

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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
 

StorminMatt

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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

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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.
 

hiuintahs

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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.
 

MAD777

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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.
 

Timothybil

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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.
 

vicv

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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
 

chillinn

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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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Woods Walker

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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.
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.
 

stephenk

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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.
 

parametrek

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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 :)
 

HKJ

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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.
 

n3eg

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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.
 

StorminMatt

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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.

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.


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

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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.
 

Woods Walker

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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.
 

vicv

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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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