Does ANYONE make a protected 18350??

fyrstormer

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I can't believe 18350s have been in use for years and I can't find any protected cells. (okay, there's one from Efest, but it's 39mm, which is so much longer than spec that it doesn't actually fit any of my 18350/18650 flashlights.) Am I looking in the wrong places? Someone somewhere must make protected cells in this size. IMRs are great, but just because they don't explode when abused doesn't mean it's good for them to be over-discharged. I have a couple 18350-powered flashlights that don't have hardware switches, and I want to be absolutely sure they won't kill their batteries if I happen to forget that I left a battery in them. (this happened once before, frying my Jetbeam TCR1 in the process.)

I'm sure someone will say "well, be more careful and don't forget next time." While that is a valid thing to say in the most uselessly academic sense imaginable, it's also not the point. I want backup in case I *do* forget by accident, and that backup can only be provided by a low-voltage cutoff circuit.
 
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noboneshotdog

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I can't believe 18350s have been in use for years and I can't find any protected cells. (okay, there's one from Efest, but it's 39mm, which is so much longer than spec that it doesn't actually fit any of my 18350/18650 flashlights.) Am I looking in the wrong places? Someone somewhere must make protected cells in this size. IMRs are great, but just because they don't explode when abused doesn't mean it's good for them to be over-discharged. I have a couple 18350-powered flashlights that don't have hardware switches, and I want to be absolutely sure they won't kill their batteries if I happen to forget that I left a battery in them. (this happened once before, frying my Jetbeam TCR1 in the process.)

I'm sure someone will say "well, be more careful and don't forget next time." While that is a valid thing to say in the most uselessly academic sense imaginable, it's also not the point. I want backup in case I *do* forget by accident, and that backup can only be provided by a low-voltage cutoff circuit.
There is a gentleman over at B*F named FREEDOM. He seems to be pretty knowledgeable about protected circuits and may be able to help.
 

parametrek

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According to my battery database there are 2 out there. Both are Keepowers being sold by Illumn.
 

fyrstormer

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I'd never heard of Illumn before, but unfortunately those batteries won't work anyway. Note that their length is 39mm, same as the Efest protected 18350s that I tried that don't fit.

If AW was able to make 16340s with protection circuits that were only 1mm longer than spec, why can't anyone seem to make a protected 18350 with the same minimal size penalty?
 

usdiver

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Muyshondt has protected 18350's but don't know about the spec. What is the overall length you need and how many batteries? 2?
I'm running 2 Exposure protected cells in my first light t Max LE and I have aws' and the capacity is only a hair less than the 18350s. The keep power 16340s I have x 2 are borderline too long and almost won't work (tailcap spring has no free space) and I m also wondering if a 18350 is rated at 750mah and a 16340 at 70mah, is there any significant gain in runtime to warrant a major battery tube rebuild as well as head modification?
 

fyrstormer

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Muyshondt 18350s are not protected. They are just normal IMRs, though perhaps they are premium-grade and actually hold close to their rated capacity unlike cheaper cells.

The Keeppower and Trustfire 18350s both claim to be able to hold 1200mAh. Assuming they're exaggerating by 20%, their actual capacity is perhaps closer to 1000mAh, which is still 25% more than the rated capacity of an AW protected 16340 -- and even the AWs never actually demonstrated their rated capacity when connected to my fancy charger/discharger. So yes, there's a significant increase in available power between an 18mm battery vs. a 16mm battery, comparable to the increase in physical volume (27%) between those two sizes.

If I can't find a reputable brand of protected 18350s, or find a way to add protection myself without needing to learn electrical engineering first, then I guess I'll just have to suck it up, buy some 16mm-to-18mm adapters, and run protected 16340s in my problematic flashlights.
 

usdiver

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My bad, sorry but I swore the Muyshondts were protected.
My HDS will take anything, but just thought will a 18350 work in the cr123 tail? I was running 1 x 17670 in my First Light Tomahawk and TMax but the circuit board isn't designed for 3.7v so had the idea of having a bigger battery tube made for more capacity but would need 2x 18350s to work... then the head needs bored a bit and the cap remade as well. Is it worth the agro? If there were more brands and more competition might be worth it but at the moment I think not. 🤔not sure so I m kinda in the same boat as you.... plus I m in Europe so battery getting isn't so easy for me.
 

CelticCross74

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The new 900mah Keeppower 18350's are WAY too long for any of my lights but I knew that going in I just wanted to give it a shot. Those are protected. Nitecore. Best 18350's I have yet to use. They fit everything, are protected button tops and thus far despite being the same 700mah as most RCR123's these new Nitecore protected 700mah 18350 cells are indeed lasting noticeably longer.

Keeppower uses THICK protection circuits. They always have for some reason. You can count on most protected Keeppower cells being longer than their competitors versions because of it.
 

night.hoodie

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LiCo and all it's protection circuit glory has seen its best days. LiCo is last gen battery tech at best, and was always a little broken to need such an ugly hack. LiMn, the new hotness, is replacing LiCo with its devil-may-care attitude towards over-discharge. If there were any scientific or rational reason for a LiMn cell to have a low voltage protection circuit, I bet anything it would be possible to find one somewhere.

Just how often do you trip protection circuits? I suppose IMR cells don't grow on trees, and being so insistant about caring about not having to care about something could save you money in the long run on cells, if indeed the habits are to overdischarge Li-ion cells often.

Otherwise, it is clear that IMR cell chem is so resilient that withstanding even repeated overdischarging only serves to reduce the cell's charge capacity and number of useful recharges. Be more careful next time and move on.

If you lose faith in a cell, you're out a few bucks. If you insist on choosing an antiquated battery chemistry and technology over a more popular modern cell chemistry that has all but entirely overtaken any competitors in its marketspace, one chosen by the market for its superior safety record and superior capacity, as well as providing higher steady voltage under load, personal cell costs could also easily skyrocket as the industry ignores, ceases support for, and finally stops selling anything like it or even remotely related to it. One day, a protection circuit, just due to its rarity and novelty, could be worth a fortune.

Best advice, don't overdischarge your cells. If you do and they're IMR, don't panic, mark the cell and see how it behaves. Believe in yourself, trust in yourself, and not some hacked-on low voltage protector strip hanging off a cell. Back in the good old days, a few years ago, low voltage protection strips served their purpose, but the industry by and large adopted a different chemistry that does not need to obsess about over-discharge because over-discharged LiMn does not behave like over-discharged LiCo, even in a charger. Not that it matters much, but I have a suspicion that abused LiMn cells will outlast delicately cared for LiCo. That's sort of a trend that seems to come up often as technology advances, stuff starts out fragile but gets more and more robust.
 

mattheww50

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I think length is always going to be an issue on a protected battery. The protection circuit is an add on, so the protection will make the protected battery significantly longer than a no-protected battery, and there just isn't enough 'slop' in the battery compartment of a device using 18350 to accommodate that extra length. The protection circuit on a 18650 often takes the length out to about 70mm, so the protected 18350 is going to end up at around 40mm. The 5mm on a 18650 makes it about 7% longer, and that causes problems on some 18650 devices. The protected 18350 is going to be about 15% longer, and that is likely to cause trouble in most applications. So unless you can get a manufacturer to produce a 18350 that is really more like a 18300, there is no solution to this problem.
 

fyrstormer

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LiCo and all it's protection circuit glory has seen its best days. LiCo is last gen battery tech at best, and was always a little broken to need such an ugly hack. LiMn, the new hotness, is replacing LiCo with its devil-may-care attitude towards over-discharge. If there were any scientific or rational reason for a LiMn cell to have a low voltage protection circuit, I bet anything it would be possible to find one somewhere.

Just how often do you trip protection circuits? I suppose IMR cells don't grow on trees, and being so insistant about caring about not having to care about something could save you money in the long run on cells, if indeed the habits are to overdischarge Li-ion cells often.

Otherwise, it is clear that IMR cell chem is so resilient that withstanding even repeated overdischarging only serves to reduce the cell's charge capacity and number of useful recharges. Be more careful next time and move on.

If you lose faith in a cell, you're out a few bucks. If you insist on choosing an antiquated battery chemistry and technology over a more popular modern cell chemistry that has all but entirely overtaken any competitors in its marketspace, one chosen by the market for its superior safety record and superior capacity, as well as providing higher steady voltage under load, personal cell costs could also easily skyrocket as the industry ignores, ceases support for, and finally stops selling anything like it or even remotely related to it. One day, a protection circuit, just due to its rarity and novelty, could be worth a fortune.

Best advice, don't overdischarge your cells. If you do and they're IMR, don't panic, mark the cell and see how it behaves. Believe in yourself, trust in yourself, and not some hacked-on low voltage protector strip hanging off a cell. Back in the good old days, a few years ago, low voltage protection strips served their purpose, but the industry by and large adopted a different chemistry that does not need to obsess about over-discharge because over-discharged LiMn does not behave like over-discharged LiCo, even in a charger. Not that it matters much, but I have a suspicion that abused LiMn cells will outlast delicately cared for LiCo. That's sort of a trend that seems to come up often as technology advances, stuff starts out fragile but gets more and more robust.
You are misinformed. LiMn has lower capacity than LiCoO and can still be damaged by over-discharging. The only battery that has ever failed on me was a LiMn battery -- unprotected, of course, because they all are. It ruined one of my expensive titanium flashlights in the process.

What I want is a battery that I can run down to its minimum safe charge and then it will shut itself off. LiMn can't offer that. (well, it could, if there were a protection circuit attached.) Don't suggest NiMH or lithium primaries, because the discharge rates on both of those are too low.

Running down a protected cell until the low-voltage cutoff kicks in is not over-discharging it. Nobody builds protection circuits that allow over-discharging. 2.75v is the minimum safe voltage for a lithium-ion battery, but it's still a safe voltage. Besides, the low-voltage cutoff engages while the battery voltage is sagging under load, so the battery's rest voltage is still above 2.75v anyway.

I have better things to do than to babysit my batteries, digging out a Sharpie and marking them every time I run them down a little too far. You can have fun babysitting your batteries if that's your jam. :laughing: A well-designed battery will keep itself working correctly so I don't have to. I put a battery in my flashlight, then I run it until the light shuts off, then I recharge the battery. This has worked just fine for me for the past 10 years.

I'm not a noob around here, I know what I'm doing. The reason IMR cells are taking over the 18350 market is not because they're better in every possible way, as you seem to believe, but because they are a popular size for nicotine vaporizers. They can safely discharge at the high amperage required to run the heating coils in those devices. Nicotine vaporizers have low-voltage cutoffs built into the control circuitry, so they don't need protected cells to prevent over-discharging. If flashlight manufacturers had gotten their heads out of...wherever their heads were stuck in...and include low-voltage cutoffs in all of their 18350-compatible designs, then we wouldn't be having this conversation. Some newer flashlights do have that feature, but that doesn't help me with flashlights I bought 5 years ago.
 
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fyrstormer

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I think length is always going to be an issue on a protected battery. The protection circuit is an add on, so the protection will make the protected battery significantly longer than a no-protected battery, and there just isn't enough 'slop' in the battery compartment of a device using 18350 to accommodate that extra length. The protection circuit on a 18650 often takes the length out to about 70mm, so the protected 18350 is going to end up at around 40mm. The 5mm on a 18650 makes it about 7% longer, and that causes problems on some 18650 devices. The protected 18350 is going to be about 15% longer, and that is likely to cause trouble in most applications. So unless you can get a manufacturer to produce a 18350 that is really more like a 18300, there is no solution to this problem.
I bought a pair of those Keeppower protected 18350s, just to see. Not only were they too long, they were also too wide. I cut the wrapper off one of them, and I discovered...another wrapper! :ohgeez: With a lower mAh rating stamped on it, too! :ohgeez::ohgeez: They took an already-wrapped flat-top 18350, attached a protection circuit and a button-top to it, and then wrapped it again. Because buying unwrapped button-top cells as raw materials for their protected cells was too hard, I guess? I dunno. Keeppower did a terrible job with their protected 18350 cells, and they should feel bad about it.

Anyway, to directly address your comment about the length penalty: After disassembling the Keeppower 18350 I measured the thickness of the protection circuit and it's only 2mm thick. An "18350" that is 37mm long might be a tight fit in a lot of 18350-compatible flashlights, but it would still fit. But the way Keeppower packaged this particular battery, it came out to 39mm, which cannot possibly fit. As for starting with an 18300 cell, it looks like that's exactly what AW used to do; I haven't unwrapped any of my AW IMR 18350s to verify this yet, but when I look in through the vent-holes in the positive terminal, I can see a space at least a couple millimeters deep, which would be more than enough room to fit a protection circuit. If only they'd thought to do so.

I miss AW. Is it possible to force a company back into business?
 
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cyclesport

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I generally just use a 16340 protected cell to prevent overdischarge in the few, little used 1 X 18350 lights I own. Sure, it's a little narrow but works fine.
 

fyrstormer

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Yeah, that's what I'm doing now, but I would like the extra capacity of a protected 18350 LiCoO cell. I see the unprotected ones are rated as high as 1200mAh nowadays.
 

usdiver

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I too am interested in the 18350 extra capacity department but so far I ve seen nothing that warrants a complete redesign of a dependable flashlight when the aw 550amh and other brands 650 and 700mah 16340's are ready available... plus I agree with fyrstormer and I also don't have time to babysit and worry about which batteries I ve overcharged or "think" I ve overcharged nor do I have the desire to change batteries "before" required just to be safe. I have an extar 4 bay dragon charger and my last batteries I ran in a First Light Tomahawk 425 lumen model till the light shut down. On the charger said they were at 0.00%
I ve charged them up and will do it again most likely. What does this do to the battery life? Is it destructive to the batteries? Hell I don't know... I wish I understood these things a bit better plus the fact I m out in the sticks now and getting 123 primary batteries isn't an option plus I have a few 16340's that ll do for awhile and several 18650's I can't use due to no light at the moment that takes em.🤔
 

fyrstormer

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Running-down batteries until the protection circuit engages causes no harm to them whatsoever. Those protection circuits aren't just there to cover our butts, they're also there to cover the manufacturers' butts -- so manufacturers program them to engage at a voltage that produces a vanishingly-small risk of failure.

One of my other hobbies is RC, which uses lithium-polymer batteries the size of a large stick of butter (or larger!), at voltages up to 33.6V, designed to discharge at peak rates of up to 100 amps for a few seconds at a time. (I mean, how else are you going to get a 20-pound monster truck to do a triple-backflip from a complete stop, right? :laughing:) These LiPo battery packs are all LiCoO chemistry (LiFePO4 is used, but only for low-power applications like radio receivers), and they are all unprotected, with the low-voltage protection provided by the electric motor controller instead. These are generally programmed to cut power when the battery reaches a rest-voltage of 3.2V per cell, but they are usually adjustable down to 3.0V per cell, meaning the loaded voltage is closer to 2.7V per cell. Despite the incredibly high workload these batteries experience, they generally last for years before the flat soft-packaged LiPo cells start to puff from outgassing, and LiPo fires are known but quite rare. Everyone in the RC hobby knows a guy who knows a guy who had a LiPo catch fire after hard use, but very few people have actually had that experience themselves. The little steel-jacketed cylindrical cells we use are an order of magnitude safer than the high-discharge LiPo batteries used in RC.

As for any "premature aging" that might be attributed to running down your protected li-ion cells until the protection circuit engages, that's actually caused by fully-charging the battery after use and then letting it sit. Li-ion batteries of all types prefer to be stored at 3.7V, and if they spend much time significantly above or below that voltage they will age faster. Unfortunately most chargers for cylindrical cells don't offer a storage-charge mode, only a full-charge mode -- you have to buy a fancy charger intended for RC or automotive use to get a storage-charge mode. But even if you fastidiously storage-charge your cells after use, they will still age even if they just sit on the shelf, because lithium is such a reactive metal that it can't be completely stopped from permanently oxidizing over time.
 
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night.hoodie

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Yeah, that's what I'm doing now, but I would like the extra capacity of a protected 18350 LiCoO cell. I see the unprotected ones are rated as high as 1200mAh nowadays.

Those high cap 18350 cells are IMR hybrids. I haven't seen 18350 LiCo in a couple years, but they maxed out around 800mAh. It is confusing the way you talk about protected or unprotected cells. I know you are not a noob. I have been enjoying your posts for years. But you must know the only chem out there with protection is LiCo. You are looking for LiCo and ONLY LiCo cells, and it is the only chem you'll see protection on, so don't be tempted by the safer, higher capacity, higher amp IMR cells... that's a different thing and you'll just end up ruining cell after cell, if you insist on remaining oblivious to the SoC of your Li-ion cells, which, btw, is a terrible practice, to rely so heavily on a low voltage protections strip as your primary indicator it is time to swap cells. I know you know better, and I have trouble believing your descriptions of Li-ion cell use.
 

fyrstormer

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A protected cell is a cell that has a low-voltage cutoff circuit attached to it, to disconnect the battery from the circuit it's powering when the battery's voltage drops too low. It doesn't matter what the internal chemistry of the cell is, only whether the cell has been equipped with a LVC circuit. LiMn cells are generally not equipped with LVC circuits, because they have a lower risk of catastrophic failure than LiCoO cells, but there is nothing about LiMn cells that prevents them from being equipped with LVC circuits. It's simply that battery manufacturers haven't seen fit to do so.

My description of how I charge and maintain my batteries is 100% factually accurate. I do exactly what I said. I know from a combination of academic knowledge and years of experience that there is absolutely nothing wrong with the way I handle my lithium-ion batteries. The super-fiddly approach that some people take to maintaining their battery is more a reflection of their personalities than the actual maintenance needs of the batteries themselves. The LVC circuits on protected li-ion batteries engage at a voltage that is still within the safe range for the cell chemistry, and it is therefore perfectly reasonable to use the LVC engagement as an indication that the cell needs recharging. Any additional fiddling you want to do is a matter of personal satisfaction, nothing more.
 
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