Disciple
Enlightened
From personal experience: at least the Chinese-made ones sometimes do.
Using Li-ion cells in LED flashlights safely
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From personal experience: at least the Chinese-made ones sometimes do.
yoyoman
Flashlight Enthusiast
^ Bummer
TSellers
Newly Enlightened
Probably is Brand dependant. I've been using GP Brand for years and so far not noticed any problem, (do my best not to leave depleted cells in the devices that they were in). Now going to try some other CHinese Brands, just got some Nitecore and some cheap 'WF' brand to try. If any leak it will probably be the latter, and I won't be surprised if their capacity is a lot less than the other two brands mentioned here.
Psychonaut
Newly Enlightened
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Is there a high drain version similar to the 20R with 3100 mAh?
origamimavin
Newly Enlightened
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Great writeup! I just got my first flashlight that takes Li-ion, so this was good information. I'm still looking up information on unprotected 10440's (i just shocked myself, somehow, by removing the safety from it), and am trying to learn as much as i can about the safety of them.
Disciple
Enlightened
This is done by a lot of people around here including me, so it's certainly not a "must-not" to everyone. Nevertheless protection circuits are not perfect (some don't work at all) so you should still make sure that any series-wired Lithium-Ion cells are properly balanced. This means that the cells are same type and age, have been tested to have similar capacity, and are starting at the same voltage every time.
So there are two types of these rechargeable Li-ion batteries: protected, and unprotected, correct?
Some lights using multiple batteries stack in series (meaning one goes in the body/tube, and than another right behind it till full), and some use battery magazines; which I don't yet know if those are actually wired parallel or series, but in any case taking for example the Olight M3X, that's a series stacking light, and so my question going out now is does anyone stack non-protected batteries as a result of my initial question? Further, what more can be said about the concerns of stacking protected batteries in the first place? Or un-protected batteries for that matter?
I get you Disciple, and I'm willing and able to invest in everything it takes to pay close attention to the status of my batteries, and definitely appreciate your input very much. For whatever reason, a windfall of lights is coming to me as a result of my impulsiveness. Of course now there's no turning back, and I do enjoy the details of things which is what brought me here.
So thanks. Lastly what's with the "Image Verification" ...is that all the time??? yikes.
Some lights using multiple batteries stack in series (meaning one goes in the body/tube, and than another right behind it till full), and some use battery magazines; which I don't yet know if those are actually wired parallel or series, but in any case taking for example the Olight M3X, that's a series stacking light, and so my question going out now is does anyone stack non-protected batteries as a result of my initial question? Further, what more can be said about the concerns of stacking protected batteries in the first place? Or un-protected batteries for that matter?
I get you Disciple, and I'm willing and able to invest in everything it takes to pay close attention to the status of my batteries, and definitely appreciate your input very much. For whatever reason, a windfall of lights is coming to me as a result of my impulsiveness. Of course now there's no turning back, and I do enjoy the details of things which is what brought me here.
So thanks. Lastly what's with the "Image Verification" ...is that all the time??? yikes.
Disciple
Enlightened
Disclaimer: I am not a battery expert. I an regurgitating what I have learned here.
Battery magazines (or carriers) can be either series or parallel, or a combination (2s2p). I would not use unprotected cells in a series-wired configuration. If you are sure that all cells are wired in parallel then it should be reasonably safe to use unprotected cells (still of the same type) as they will inherently balance. See Li-Ion Parallel Charging for testing and explanation. However it may still be possible to over-discharge the cells depending on the circuitry of the light, and this can be dangerous as it may damage the cells in a way that can later cause an internal short (read: "vent with flame" which means explosion in a sealed light). If you choose to use unprotected cells (either a single cell or in parallel) make sure the light has a low-voltage cutoff or inherently shuts off before the cells are over-discharged. The forward bias voltage of the LED often serves this purpose. See HKJ's battery selection guide for more. In any light an unprotected cell is at greater risk from an external short or from over-charging from a malfunctioning charger, therefore the protection circuit adds an extra layer of safety in any application.
Series-wired cells are more dangerous because one cell can drive another (depleted) cell into reversal causing a breakdown of the internals of the cell and smoke/fire/explosion/etc. This is why we must check that the cells are properly balanced.
Since charge state can be inferred from voltage in Lithium-Ion cells we can use voltage checks to check capacity. When you charge a set of sells for series application check the voltage after letting them rest for a few minutes. The voltage should be nearly the same. (+/- 0.02v I believe I read? I'm not sure; research this yourself.). A low voltage could be the sign of a degraded cell. When you first use the cells (in series) periodically stop, open the light, and check individual cell voltage, again after a few minutes of rest. The cell voltages should drop at the same rate; one dropping faster than another is a sign of a cell with diminished capacity, and if severe it could result in that cell being depleted early and driven into reversal.
By "Image Verification" do you mean a form of CAPTCHA? If so that must be because you are a new member because I don't see those.
Battery magazines (or carriers) can be either series or parallel, or a combination (2s2p). I would not use unprotected cells in a series-wired configuration. If you are sure that all cells are wired in parallel then it should be reasonably safe to use unprotected cells (still of the same type) as they will inherently balance. See Li-Ion Parallel Charging for testing and explanation. However it may still be possible to over-discharge the cells depending on the circuitry of the light, and this can be dangerous as it may damage the cells in a way that can later cause an internal short (read: "vent with flame" which means explosion in a sealed light). If you choose to use unprotected cells (either a single cell or in parallel) make sure the light has a low-voltage cutoff or inherently shuts off before the cells are over-discharged. The forward bias voltage of the LED often serves this purpose. See HKJ's battery selection guide for more. In any light an unprotected cell is at greater risk from an external short or from over-charging from a malfunctioning charger, therefore the protection circuit adds an extra layer of safety in any application.
Series-wired cells are more dangerous because one cell can drive another (depleted) cell into reversal causing a breakdown of the internals of the cell and smoke/fire/explosion/etc. This is why we must check that the cells are properly balanced.
Since charge state can be inferred from voltage in Lithium-Ion cells we can use voltage checks to check capacity. When you charge a set of sells for series application check the voltage after letting them rest for a few minutes. The voltage should be nearly the same. (+/- 0.02v I believe I read? I'm not sure; research this yourself.). A low voltage could be the sign of a degraded cell. When you first use the cells (in series) periodically stop, open the light, and check individual cell voltage, again after a few minutes of rest. The cell voltages should drop at the same rate; one dropping faster than another is a sign of a cell with diminished capacity, and if severe it could result in that cell being depleted early and driven into reversal.
By "Image Verification" do you mean a form of CAPTCHA? If so that must be because you are a new member because I don't see those.
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Thank you, Disciple. A lot of information to consider. I appreciate your reply very much. The CAPTCHA thing is gone too. What about below-freezing temps with these batteries. As far as plain storage, loading them with actual use, or charging while too cold? Seems like I hear the primary type 123 are good to go in basically all temps. I'm concerned about damaging my rechargeable ones. Thanks again.
Disciple
Enlightened
I don't have that data. I'll see what I can find.
thedoc007
Flashlight Enthusiast
Storing them cold is fine, and if they will work, using them cold is fine too - their performance will be lower in extreme cold, but they will warm up in use, and there is no safety issue there I am aware of. But DO NOT charge a frozen battery - that can definitely lead to problems.
From Battery University:"Many battery users are unaware that consumer-grade lithium-ion batteries cannot be charged below 0°C (32°F). Although the pack appears to be charging normally, plating of metallic lithium can occur on the anode during a subfreezing charge. The plating is permanent and cannot be removed with cycling. Batteries with lithium plating are known to be more vulnerable to failure if exposed to vibration or other stressful conditions."
So to repeat, DO NOT charge any lithium ion cell that is below freezing. Storing or using them cold is fine.
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TSellers
Newly Enlightened
Thanks for the reminder. I often place the batteries from the headlamps I've been using for a night ski straight into the charger as soon as I come in the door so I won't forget. In fact I did that tonight. Although they are usually coming in from a warm car ride, it's well worth it for me to always be aware of that.
BarneyBG
Newly Enlightened
Quick question...
According to this thread and another one about circuit protection - the protection is there just in case, it shouldn't be relied upon and it shouldn't enter into any "estimations" (e.g. "my cell is protected, so I can torture it"), right? OK. But what is the reasonably safe voltage limit that I should "train" myself not to cross? It says that 3.0V is the absolute minimum for discharging, but if I'm outside, using my torch - at what voltage should I stop using my TF 18650-protected? I wanted to test how much can I use my torch so I turned it on and stopped it as soon as the voltage turned 3.6V. The whole process took 3.5h so I assumed that's the reasonably safe time I can use it. True or not? Can I squize-in some more time or it's pushing it with negligible benefits?
According to this thread and another one about circuit protection - the protection is there just in case, it shouldn't be relied upon and it shouldn't enter into any "estimations" (e.g. "my cell is protected, so I can torture it"), right? OK. But what is the reasonably safe voltage limit that I should "train" myself not to cross? It says that 3.0V is the absolute minimum for discharging, but if I'm outside, using my torch - at what voltage should I stop using my TF 18650-protected? I wanted to test how much can I use my torch so I turned it on and stopped it as soon as the voltage turned 3.6V. The whole process took 3.5h so I assumed that's the reasonably safe time I can use it. True or not? Can I squize-in some more time or it's pushing it with negligible benefits?
Swedpat
Flashlight Enthusiast
Thanks for the information. More than 3,5 years late to say it but this is still valuable and actual.
So much one needs to know when it comes to batteries, and I am still learning more. Do I understand this right that I therefore never should use Li-ion batteries in regulated flashlights who lacks over discharge protection suited for the voltage of the used Li-ion(s)?
What I have read the overdischarge protection of a 3,7V Li-ion kicks in at 2,5V.
If I then use 2x18500 or 18650 to run, for example, a Malkoff M61SHO dropin, Information from the site: "The input voltage is 5.5- 12 volts. Below 5.5 volts it will drop out of regulation. Below 5 volts it will begin to flash and below 4.5 volts it will shut off. "
This dropin consequently doesn't work at all with a single cell. But with two cells it means that it drops out of regulation when the voltage of each cell is 2,75V. And because this dropin is intended for two Li-ions I presume it's ok to run the light until it drops out of regulation, though the voltage is just slightly over the cells protection limit.
But how to do with a Malkoff M61: "The input voltage is 3.4 - 9 volts. Below 3.4 volts it will drop out of regulation and run direct drive."
Consequently it should be considered as "forbidden" to run this dropin at all with two Li-ions: the light will be flat regulated until the protection circuit kicks in and because there is no warning for when this will occur; is that a correct conclusion ?
So much one needs to know when it comes to batteries, and I am still learning more. Do I understand this right that I therefore never should use Li-ion batteries in regulated flashlights who lacks over discharge protection suited for the voltage of the used Li-ion(s)?
What I have read the overdischarge protection of a 3,7V Li-ion kicks in at 2,5V.
If I then use 2x18500 or 18650 to run, for example, a Malkoff M61SHO dropin, Information from the site: "The input voltage is 5.5- 12 volts. Below 5.5 volts it will drop out of regulation. Below 5 volts it will begin to flash and below 4.5 volts it will shut off. "
This dropin consequently doesn't work at all with a single cell. But with two cells it means that it drops out of regulation when the voltage of each cell is 2,75V. And because this dropin is intended for two Li-ions I presume it's ok to run the light until it drops out of regulation, though the voltage is just slightly over the cells protection limit.
But how to do with a Malkoff M61: "The input voltage is 3.4 - 9 volts. Below 3.4 volts it will drop out of regulation and run direct drive."
Consequently it should be considered as "forbidden" to run this dropin at all with two Li-ions: the light will be flat regulated until the protection circuit kicks in and because there is no warning for when this will occur; is that a correct conclusion ?
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StorminMatt
Flashlight Enthusiast
One thing I like to do with NiMH is an occasional runtime test. This way, I know how long my light will run if I use it for long stretches. It also gives me an idea of the health of my batteries. Similar testing, along with voltage readings at regular intervals, might not be a bad idea with Li-Ion. If you know about how long your batteries will run a light before voltage drops below a certain level, you are less likely to overdischarge them. And since most Li-Ion chemistries generally experience gradually decreasing capacity over their lifetime (unlike NiMH), doing runtime tests at regular intervals will let you know how long you can use your light as the batteries age.
TSellers
Newly Enlightened
I would use a protected cell in a light that does not have a driver with a shutoff algorithm. (Actually I would never use a light that does not have a protection circuit built in).
You mean that's where a protection circuit kick's in? I think most are higher than that are they not? I thought 2.5 was the level cited by Battery University as the lowest level a Li-Ion cell can by taken to for up to a week.
2 cells in series your problem is not the low voltage cutoff, if they were unprotected cells then your concern is with internal resistance causing one of the cells to reverse polarity and vent. Thus you need to use balanced or protected cells in that configuration.
Can't really understand your question here. Above you mention that the drop-in needs 5.5-12V, then this appears to state the same drop in uses 3.4-9 V, or am I getting it wrong?
I feel comfortable using unprotected cells in my single cell Spark headlamps for example because they have good protection built into them already for low voltage, overvoltage, and reverse polarity. If I were running any 2 cells lights in series I'd use protected cells due to the potential issues with internal resistance from unbalanced cells causing problems with one of the cells.
These opinions are just what my understanding of general guidelines for Li-Ion are from reading the comments of others in the fourms that have more experience than me (that's why I waited 3 days before replying), and from the Battery Universitie's website, so of course you should double check anything I've said before potentially acting on it as good advice.
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Swedpat
Flashlight Enthusiast
Sorry, expressed me a bit unclear. I compared between the standard M61 which is regulated between 3,4 and 9V and the slightly higher output M61SHO which is regulated between 5,5 and 12V. However I think the standard M61 actually drops out of regulation at slightly higher voltage than 3,4V: with several of my different M61 dropins the brightness is lower with a single 17670/18650 than 2xCR123 or becomes lower after a short while.
I only have high quality Li-ions and only use the same brand and model in pairs. Once I have started to use a pair I mark them and let them continue together. The charger is Pila IBC. I don't know how much they differ from each other. The same brand and model of the higher grade batteries should differ only very slightly I think?
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TSellers
Newly Enlightened
Well I'm actually running some unprotected cells in a Fenix TK76 in series. They are matched and I monitor and measure them each time they are charged in the same fashion as you. I do not use that light very much as it was given to us for evaluation, but in the long run I accept that I should be using protected cells in it, but at the moment, and given how rarely I use the light, I cannot afford to dedicate 4 expensive protected cells to it. I guess if I was going out on a field operation that I knew would be causing the light to get constant use I would simply swap the cells out for protected ones at that point. Ironically the place I really need to use 14500 protected cells the most is in AA cell packs for VHF radios, but those packs simply do not have the room, always seems to be the problem with protected cells in places you need them the most.
