Is my 18650 dead?

Toulouse42

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Hi All

Last night my 18650 flashlight died on me. I assumed that the battery was just depleted but today when I put it on the charger (Fenix ARE-C2) it didn't register at all. Zero volts. The same on a different charger. (Nitecore D4). The battery is over 7 years old and is a Nitecore NL186 2600 mah. This is the first time this has happened with these. My inclination is just to toss it.

Are there any things you recommend I try before I toss it out?
 

PaladinNO

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My 2 Cents would just be to recycle and replace it at this point. After 7 years, I would say you have gotten your money's worth out of it.
Unless you know what you are doing, with equpment on hand, and want to try experimenting on it (insert Frankenstein quote), I would toss it out.

As a replacement, I am personally a big fan of the Nitecore NL1835HP (current model is the NL1836HP).
 

Toulouse42

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Thank you both. I'm not keen on playing with Li Ion batteries as I don't have the skills.

I'll toss it.
 

aznsx

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Hi All

Last night my 18650 flashlight died on me. I assumed that the battery was just depleted but today when I put it on the charger (Fenix ARE-C2) it didn't register at all. Zero volts. The same on a different charger. (Nitecore D4). The battery is over 7 years old and is a Nitecore NL186 2600 mah. This is the first time this has happened with these. My inclination is just to toss it.

Are there any things you recommend I try before I toss it out?
Based on how I read your post, this appears to be exactly what I experienced a couple of nights ago, and on another occasion a couple of weeks ago. There was no equipment failure /malfunction involved in my cases, only a failure of the user, as this DA had become distracted by life and lost track of usage of the light since last cell swap / charge. I swapped cells and resumed using the light.

Because the light shut off during what appeared to be normal operation, it was apparent to me that I had simply over-discharged the cell. They are "protected" cells with a safety circuit which opens (shuts off) the output when the cell voltage drops below a designed threshold value to prevent me from discharging them to a level which could damage them or otherwise create a safety issue when recharged. The cells were doing exactly the job I paid them to do (thankfully). Simple operator malfunction.

This 'under-voltage / over-discharge' feature / function in a separate cylindrical cell is generally not auto-resetting, and must be intentionally reset before charging and resuming use of the cell (not unlike a typical 'circuit breaker'). Many chargers have this function. One of mine (Xtar VP2) does this by default when a cell is inserted, as it maintains a voltage across the cell terminals of an idle slot that provides the reset function. Another (MC3000) displays the lack of a valid cell, I then push a button to reset the safety circuit, it displays the open circuit voltage of the cell following reset, and I then push another button to begin charging. I prefer the latter design, because I prefer to be informed.

Most rechargeable consumer electronic devices of course handle this automatically. When the device shuts down, the user plugs in the charger.

In the case of separate cylindrical cells like ours, if one's charger does not provide this function, they may be reset by briefly (single-digit seconds) applying a voltage (in parallel) to their terminals directly. That's often accomplished by simply connecting a normal / charged cell directly in parallel with the one that's tripped (+to+, -to-). I don't need to do this, but I'd just rubber band them together and press the buttons down on a conductive surface, then briefly connect the 2 (-) terminals together w/ something conductive (wire/paper clip/tool, etc.)

Your issue's likely been resolved, but just thought I'd post this for those who might not be familiar with such.

EDIT: If a cell cannot be reset in this way it should be taken out of service, and should NOT be disassembled.

I should also add that these instances I experienced were during non-critical use of my light in a not-critical application.
 
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Lights and Guns

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I had (4) unprotected cells completely die on me last week. They are several years old so didn't think much of it, not 100% sure what the cause was.

Had all (4) cells powering one of my lights. The flashlight in particular is quite small and outputs a ton of lumens. The flashlight was set on the floor for a while as I got distracted with something else for the moment, and didn't switch the light off.

When I returned, the light was off but way too hot to handle without burning myself.

I let the light / batteries cool off for a while and then tried charging the cells on multiple chargers I have. None of them registered. I'm assuming I either over-drained them or they were damaged due to the high temp of the light? Regardless, I recycled them as they are older cells and not much of a tinkerer when it comes to batteries, the juice isn't worth the squeeze.
 

aznsx

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I had (4) unprotected cells completely die on me last week. They are several years old so didn't think much of it, not 100% sure what the cause was.

Had all (4) cells powering one of my lights. The flashlight in particular is quite small and outputs a ton of lumens. The flashlight was set on the floor for a while as I got distracted with something else for the moment, and didn't switch the light off.

When I returned, the light was off but way too hot to handle without burning myself.

I let the light / batteries cool off for a while and then tried charging the cells on multiple chargers I have. None of them registered. I'm assuming I either over-drained them or they were damaged due to the high temp of the light? Regardless, I recycled them as they are older cells and not much of a tinkerer when it comes to batteries, the juice isn't worth the squeeze.
That's a whole different animal (compared with my experience(s)), and frankly sounds a little scary to me. I'm not sure I've ever heard a story like that. I agree and I would retire those too. For that matter, I'm not even sure I'd trust the flashlight at this point! Either the cells or the light weren't acting in your best interest if you were left with a handful of dead cells. I have no idea about root cause, but even though I screwed up, fortunately my cells are still fine. They aren't that expensive, but I can't afford to be trashing them either. That could get expensive.
 

Toulouse42

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Hi All

Yes DaveTheDude that is what I will do. I just worded it badly. All batteries that I use go to recycling.

I might try the suggestion from aznsx. However my experience is slightly different. I was using my Nitecore MH20 for only a minute or so to look for my cat. It didn't die on me then. I turned it off and maybe 10 minutes later tried again but this time got no light at all. I was surprised as that battery had not had much use. I generally recharge them way before they are depleted but it is possible I lost track of how long I had actually used it.

Thanks all for your feedback. This is one thing I need to be careful about.
 

aznsx

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Hi All

Yes DaveTheDude that is what I will do. I just worded it badly. All batteries that I use go to recycling.

I might try the suggestion from aznsx. However my experience is slightly different. I was using my Nitecore MH20 for only a minute or so to look for my cat. It didn't die on me then. I turned it off and maybe 10 minutes later tried again but this time got no light at all. I was surprised as that battery had not had much use. I generally recharge them way before they are depleted but it is possible I lost track of how long I had actually used it.

Thanks all for your feedback. This is one thing I need to be careful about.

Gotcha. That's exactly why I had this qualifier on the description of my experiences

Because the light shut off during what appeared to be normal operation

Yours didn't die while operating, but rather it worked one time, then when turned on the next time, failed. I didn't know that. That doesn't necessarily mean that the cell's over-discharge cutoff wasn't responsible, so it's definitely still a possibility. That does clarify that the light wasn't found dead after sitting idle for some period while stored, so your scenario still establishes that the cell had not tripped while stored, and that means the voltage was still above threshold trip point when you turned it off. That still establishes that the voltage had not already drained below threshold level in storage, which would leave open the possibility that it was already drained to a possibly 'dangerous' level. That would indicate that it's still OK to try to reset the protection circuit (in case it's indeed tripped), so you might as well try it. As I said, if that doesn't reset it and restore output, I would retire the cell. Over-discharge / under-voltage is by far the most likely cause of a cell going to '0V' output suddenly.

I'm not familiar with that light's operation, but many lights draw more current at initial power-on than they do subsequently. It might well have been drawing more current at the second initial power-on than it was when you shut it off previously; either because of ramping output down, or being at lower output previously due to temp control. If the cell was nearing the protection threshold already, that could cause it to pull the cell voltage down lower when turned back on than it was when you turned it off, which could explain why that's when it tripped then, so over-discharge protection shutoff is still a real possibility.

You may want to retire the cell anyway since it's rather old, which is fine, but just keep this info in mind for next time, and don't assume it's a 'failure' when a cell drops to '0V'. It may be doing exactly as it's supposed to, just like in all my such experiences.

I'm going to blame the cat, even though when I try that with mine (Ringtail), he never accepts responsibility. He's smarter than me;-)
 
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Toulouse42

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aznsx - I just tried your suggestion but no result at all. Thanks for the help but I'm going to recycle this one.

I think I'm smarter than my cat but she doesn't agree.
 
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