Years of reading and battery safety is a mystery to me

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This is the light im interested in.

https://flashlight.nitecore.com/product/p20ix

Would this light be pretty much plug and play without giving much though to it and relatively safe?

Anything I should know about, as this light is pushing a lot of lumens.

First I would ask, given the batteries you are currently using, that you feel the need to have a flashlight that is equivalent to 4 car headlights almost? I rarely use the 1100 lumens setting on a somewhat floody light I have. Just an FYI, flood is almost always more useful.

Stick to name brand cells, or what Nitecore sells you and you will never have anything to worry about. I keep my lithium cells / flashlight in the fridge (for long storage, I put them in the freezer). Unless you are discharging it every day, if you store that flashlight/battery in the fridge, the battery will likely last over a decade. I have some 10+ year old fairly cheap cells I keep in the freezer that still have 90% capacity.

Oh, and I blocked Chillin a while ago. Some people know a lot less than they think they do. I don't have time for that.
 

chillinn

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FWIW, Scotty321 was correct (and I was wrong) about the NiteCore i Series cell, in that the cell is proprietary and has both positive cathode and negative anode on the top of the cell. It is the only 21700 that will work in that light, and the cell will only work in that light and a few other NiteCore flashlight models.

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Note the misleading plus and minus signs where we expect them to be.

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The metal ring is probably the anode.

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The metal bottom is misleading, it isn't the anode.

I am hugely disappointed in NiteCore for this manipulative lock-in and money grab strategy. NiteCore sells their proprietary battery for $22, meanwhile the best quality 21700 cells on the planet cost less than $8 when they're expensive. NiteCore sells the p20ix, cell included, for about $120. Anyone can get a nicer 21700 flashlight with a better driver and a myriad of LED options, some that make it brighter than the p20ix, for less than half the price, one that will accept and use any 21700 cell that can put out the rated amps, as well as 18650 cells, which are excellent, cheap and easy to find. Or one can find a similar flashlight for half the price that is brighter and also accepts conventional 21700 cells.

A flashlight is a tool. Does anyone really want their tools manipulating them? Get a Noctigon or Emisar and an Acebeam instead and have have 2 better flashlights for the price of one of NiteCore's subversive and overreaching models.
 
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airwolf41

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First I would ask, given the batteries you are currently using, that you feel the need to have a flashlight that is equivalent to 4 car headlights almost? I rarely use the 1100 lumens setting on a somewhat floody light I have. Just an FYI, flood is almost always more useful.

Stick to name brand cells, or what Nitecore sells you and you will never have anything to worry about. I keep my lithium cells / flashlight in the fridge (for long storage, I put them in the freezer). Unless you are discharging it every day, if you store that flashlight/battery in the fridge, the battery will likely last over a decade. I have some 10+ year old fairly cheap cells I keep in the freezer that still have 90% capacity.

Oh, and I blocked Chillin a while ago. Some people know a lot less than they think they do. I don't have time for that.
Wow, so these batteries can be stored long term in a freezer?

Could you please just briefly elaborate why that is helpful.

I'm so entirely confused because I want to use this nitecore flashlight in cold temps, below 32 degrees and this whole thread has enlightened me to this so called thermal expansion, which has me thinking the light will explode if ran on high when it was sitting in the cold and now I'm supposed to store the batteries in the freezer?

I know that storing and using the battery is two different things, but if you can please briefly explain this, it would be appreciated.
 

chillinn

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Wow, so these batteries can be stored long term in a freezer?

You're welcome to do that, but it's a myth. Storing batteries in the freezer will neither increase performance nor affect the capacity, nor reduce self-discharge. JAOFLEDGuy is chock full of these little chestnuts.

Snopes said:
No, storage in a refrigerator or freezer is not required or recommended for batteries produced today. Cold temperature storage can in fact harm batteries if condensation results in corroded contacts or label or seal damage due to extreme temperature storage. To maximize performance and shelf life, store batteries at normal room temperatures (68°F to 78°F or 20°C to 25°C) with moderated humidity levels (35 to 65% RH).

I want to use this nitecore flashlight in cold temps, below 32 degrees

You can, and I wouldn't worry about that. What is mildly concerning is you seem to want to purchase an expensive, high performance light to store it over the winter in your car. Get a cheap (yet still awesome) AA light to store in your frozen car. Carry your high performance flashlight instead of storing it.
 
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KITROBASKIN

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Given the nature of this thread, check out the performance characteristics near technical specifications for this LFP battery. I do not endorse this brand but appreciate these graphs, including temperature affects.

 

chillinn

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Lithium ion cells, LiFePO4 included, perform very well in cold temperatures. But even LiFePO4 cells are not immune to the consequences of thermodynamics. Running a lot of amps quickly through a frozen LFP cell will result in it rapidly heating up, and can result in the same kind of thermal shock and injury seen elsewhere. The trick to avoiding thermal shock is simply to not quickly and instantly heat up something that is frozen such that it is shocked by the change in temperature. Raising the temperature slowly is wiser, as this will avoid all the troubles that come from thermal shock. This has nothing to do with how a battery performs in cold weather. It really just has to do with physics.
 
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airwolf41, I apologize for you having to put up with a toxic member who think he knows far more than he actually does:

1) Storage of Lithium at cold temps in 100% state of charge. That is absolutely not myth. Anyone who claims that is out of touch. For Lithium Cobalt, Lithium Manganese Cobalt, etc. pretty much any cell that has a high voltage close to 4.2V, the worse storage condition is 100% state of charge, i.e. fully charged, and high temp. https://forum.digikey.com/t/li-ion-lipo-battery-storage-and-permanent-capacity-loss/19946

0a302a1de18a098ad27a569f908568b4a4e50d55_2_690x377.png


This is very well known by most people. LiFeP04 does not have as much of an issue. At 25C and 0C, the capacity loss is pretty similar. Get up to 40C and the capacity loss accelerates quickly.

figure2.png


Here is another one .... https://www.analog.com/en/technical...oner-extends-the-life-of-liion-batteries.html

I could post 100's of links: https://arxiv.org/abs/2103.02166
 
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Now let's talk about Intrinsic Safety.

Actions speak louder than words:

https://www.electronicspecifier.com...ifepo4-high-performance-battery-pack-launched

1674707029143.png


This is a test of older A123 LiFeP04, where under charge, i.e. with current passing through them, they still did not ignite a methane atmosphere.
https://www.researchgate.net/public...hium_and_lithium-ion_cells_within_methane-air

Some LiFeP04 will ignite from something like a metal puncture, mainly older prismatic cells. Are you planning to puncture your flashlight with a nail? Probably not.
 

chillinn

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airwolf41, I apologize for you having to put up with a toxic member who think he knows far more than he actually does... Anyone who claims that is out of touch... This is very well known by most people.

This is passive aggressive garbage, also employing the bandwagon and sweeping generalization fallacies. Fallacies, of course, are invalid and unsound argument. JAOFLEDGuy just can't seem to focus on the argument and stop attacking the man, known as ad hominem fallacy. And I guess believes what is popular must be true, that as long as enough people believe in absolute horse manure, it magically becomes real. This is a bandwagon fallacy. Anyone that disagrees with him is out of touch. This is a sweeping generalization, which is fallacious reasoning.

Post your links, and I will debunk every single one, because it is, among many others, a common misconception.

To wit, none of your links mention a consumer refrigerator or freezer. Nor do they mention humidity levels or wet bulb temperature. Seems like they may have run their tests under laboratory conditions, which will not be found inside anyone's refridgerator.

A frost free freezer at 0°F will have humidity levels between 35%-40%. When it goes into its defrost cycle twice a day for about 20 minutes, the temperature will rise about 10° and the humidity levels will spike to 70%-80%, which will slowly fall over the next 4-5 hours. It does this every day, day in day out. Any time the door is opened, the temperature will increase and the humidity will spike. This is because as air warms, the more water molecules it can hold, thus the humidity increases. When the air cools it will lose its humidity in the form of condensation.

These are not appropriate conditions to store Li-ion cells, and whatever could be gained in reducing self-discharge, which is already low for a Li-ion cell, is completely defeated and then some due to humid air being more conductive than dry air.

While a cold environment obviously can slow self-discharge, refrigerators and freezers are not safe to put batteries in for the reasons mentioned above: the moist environment will in fact cause higher self-discharge as well as cause condensation to form on the batteries. This in turn will lead to rust and other damage, which can short your cells. This is highly unlikely to happen in an appropriate place to store cells, which is a cool and dry environment.
 
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Now let's talk about high discharge rates at cold temperatures and what will really happen.

1) The cells will increase significantly in internal resistance. Because of this, when you attempt to draw heavy current, i.e. turbo mode, the flashlight will detect too low of a voltage and reduce the output to one of the lower settings.

2) The internal resistance will still be high, but the current lower, so the cell will heat up.

3) As the cell heats up, the internal resistance drops.

This is stressful to the cell, hence running on turbo when really cold would not be my recommendation, but you are going to do over 1,000 lumens at a relatively gentle 1C discharge rate.

Now, this is discharging. Charging the battery at cold temps at high rates is bad, as it can cause gassing, even in a lithium battery.
 
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SYZYGY

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You're welcome to do that, but it's a myth. Storing batteries in the freezer will neither increase performance nor affect the capacity, nor reduce self-discharge.

is it really a myth, though? unless it was all bs, i feel like i've seen some convincing experimental evidence that suggests capacity loss slows down at lower temps. it also makes sense conceptually (chem kinetics are temp dependent). also, your article is from snopes, it's not about liion batteries, and it provides advice from large manufacturers to consumer masses. ime, such advice is usually bad for a variety of reasons. it can be 'cover your arse' advice, or it assumes people are stupid, or it only explains the safest option for brevity.

When it goes into its defrost cycle twice a day for about 20 minutes, the temperature will rise about 10° and the humidity levels will spike to 70%-80%, which will slowly fall over the next 4-5 hours. It does this every day, day in day out.

you're totally right about this stuff. but smart people use chest freezers (no defrost cycle) for anything stored longer than a few months :) , and they also store sensitive things in MAP. something with adequate moisture and vapor barrier (like metallized mylar), with most air removed, perhaps with a desiccant packet or O2 scavenger as needed.

for batteries, the defrost cycle probably isn't a problem i'd think. it's still nice and chilly on average which should help, and moisture problems are totally mitigated by keeping them stored appropriately. probably impulse sealed in aluminized mylar bags with most of the air squeezed out is good enough.
 
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One thing Chillin got right is this flashlight does seem to require Nitecore's proprietary 21700 format. I would not touch it personally, but if you want something that will run also with primaries, then I guess it is an option.

I would consider that your real usage case is. Do you need that many lumens, what beam pattern, etc.

Another area I would disagree. You won't get a high quality flashlight, with a wide range of modes, and 4000 lumens for 1/2 the price. You may find something advertised with that many lumens at 1/2 the price, but odds are the claim will be fake, you won't have the variety of modes, the build quality will be low, the optics questionable, the LED placement poor .... well you get the idea. You do get what you pay for.

Olight is playing the same game with their 21700, though it seems to be very similar to standard. They have a flashlight very similar to the Nitecore. I would not be surprised if a standard protected 21700 worked.
 
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"When it goes into its defrost cycle twice a day for about 20 minutes, the temperature will rise about 10° and the humidity levels will spike to 70%-80%, which will slowly fall over the next 4-5 hours. It does this every day, day in day out."

More half truths and misinformation. The air temp may rise 10F, 5.5C, but it will be about 0F normally. This is the air temp. The air has very little heat capacity. The food, the walls, (batteries) are where all the heat capacity is, and they will stay much colder. Because of this, once the freezer returns to its cooling cycle, the air temperature rapidly goes down.

Guess what, when you open the freezer, the room air will replace the air inside the freezer. When you close the freezer, that air will cool rapidly due to the far higher thermal mass of the food and the freezer materials. The humidity will spike rapidly to 100%. Never mind 70-80%, 100%. That probably happens a few times a day at most houses. 22C air, 50% relative humidity is enough moisture at -18C to reach 100% humidity 6 times over. That is why you need a defrost cycle. That moisture condenses on the coolest thing.

It is a non issue. Anyone heard of Tupperware or a Ziploc bag?

Basically Chillin copied and paste what ONE PERSON said on Quora, without doing any real research. He has no idea if that person's answer was professionally qualified, how applicable to modern equipment it is, what the practical implications are, etc.
 

chillinn

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is it really a myth, though? unless it was all bs, i feel like i've seen some convincing experimental evidence that suggests capacity loss slows down at lower temps.

It's a myth because your freezer is full of water. You can't see it because it is vaporized in the air. Your freezer also does not hold a constant temperature, but changes quite a bit from the door opening and closing, but even if the door was kept closed, the temperature would still fluctuate enough to cause condensation to form on everything in it, including your batteries. Does it sound like storing water droplets on your batteries is a good idea? You lose far less capacity storing your cells at 60°F in a dry environment than at 0°F in an environment that fluctuates between 30% humidity and 80% humidity at least twice a day, which is what is happening in your fridge if you never open the door. If you do open the door ever, then it happens more often, and each time, really.

More half truths and misinformation.

Glossing over details, commonly known as handwaving, is misdirection, and fallacious argument.

The air has very little heat capacity.

If the temperature rises 10°, then it has enough heat capacity to spike the humidity levels up to 90%, which when it cools back down 10° will precipitate out as condensation, which forms on every surface therein, including inside zip lock bags, as the air in the bag, though sealed, is the same air with the same relative amount of water.

The food, the walls, (batteries) are where all the heat capacity is, and they will stay much colder.

Yes, and this is precisely what causes the problem. Ever pull a canned soda out of your fridge and leave on the counter? The can is a lot colder than the air in your kitchen. What happens? Does the can get dryer? Or does condensation form on it? I don't know what goes on in your kitchen, but in mine we obey the laws of thermodynamics.

Because of this, once the freezer returns to its cooling cycle, the air temperature rapidly goes down.

That is correct, and when the air cools, its capacity to hold the moisture that the warmer air was holding is reduced. The mosture has to go somewhere, and in fact we can see it precipitate out in the form of condensation on all surfaces, which then freezes, thaws, freezes, and becomes layers of frost.

Guess what, when you open the freezer, the room air will replace the air inside the freezer.

That's right, except you're failing to realize is the air in your home is likely between 40% and 60% humidity, higher than in your freezer. In fact, all the water in your freezer came from the air in your home, and every time you open the door, you're replacing the moisture that turned into frost.

When you close the freezer, that air will cool rapidly due to the far higher thermal mass of the food and the freezer materials. The humidity will spike rapidly to 100%. Never mind 70-80%, 100%. That probably happens a few times a day at most houses. 22C air, 50% relative humidity is enough moisture at -18C to reach 100% humidity 6 times over. That is why you need a defrost cycle. That moisture condenses on the coolest thing.

Very clever of you to agree with me. I suppose the frozen batteries won't be among the coolest things?

It is a non issue. Anyone heard of Tupperware or a Ziploc bag?

Because you've been dehumidifying the air in your Tupperware and Ziploc bags all along. Why did I not see that coming?

Basically Chillin copied and paste what ONE PERSON said on Quora, without doing any real research. He has no idea if that person's answer was professionally qualified, how applicable to modern equipment it is, what the practical implications are, etc.

Now you're clairvoyant. This is known as the mind-reading fallacy. Effectively you have no ability to be rational, and in desperation, you think that by fantasizing about what I did, that you can somehow be persuasive, hoping no one will notice no matter what I did is entirely irrelevant. By calling me stupid, you don't need to actually address my argument. Yet my argument stands, almost like a statue, only appearing bulletproof because you have completely ignored it.
 
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SYZYGY

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Does it sound like storing water droplets on your batteries is a good idea?

i get what you're saying, but did you miss most of my post where i explained how to prevent that from happening? i'm not interested in storing cells in a wet environment at any temp.
 

chillinn

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Why don't you put a digital hygrometer and thermometer in your chest freezer that stores its data in memory. These things are pretty cheap. Conversely, you can go very cheap and get something for a humidor which just displays the data, and look at it once in a while. Then you'll know it isn't holding as constant a temperature as you believe, and it isn't as dry as you think, nor do the humidity levels remain constant. This isn't lab equipment with tightly controlled tolerances. It's a consumer grade product. What I know is every single time I have ever opened a chest freezer, I literally watched as a wave of visible water vapor poured out of it. You've never seen that? If we looked in your chest freezer, we wouldn't see any frost at various stages and layers of being frozen and liquified many many many times?
 
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SYZYGY

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i guess you didn't read my post. np.

the atmosphere in the freezer is isolated from the atmosphere of the batteries (a bag which has dry air and/or does not have enough volume to produce appreciable liquid at freezer temps).
 
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