Battery Shelf Life for 18650?

I keep a few flashlights socked away in a bugout bag with some batteries.

Can I store the batteries indefinitely or will they go bad in storage? I've also been reading up on the 1859 Carrington EMP Event. I assume flashlights without batteries are okay and shouldn't be affected, but protected batteries have chips in them. Can they be knocked out by EMP?

:wave:Also, how do Klarus batteries fare compared to other quality batteries?

THANKS!

All batteries have limited lifetime, some cheap batteries may only last a year or two, the longest lived batteries may last 20-30 years. You will have to check for the types you use.

EMP is a electromagnetic field, it means it is hardest on long things (Like the mains wiring that runs for 100's of kms), shorting thins will get less effect and anything inside metal will be protected. A loose 18650 battery only has a few mm where it can receive the EMP puls on and I doubt it will damage a protected cell.

I have tested a few (very few) Klarus cells here: http://lygte-info.dk/review/batteries2012/CommonSmallIndividualTest UK.html and they did do well.

Confederate said:

I keep a few flashlights socked away in a bugout bag with some batteries.

Can I store the batteries indefinitely or will they go bad in storage? I've also been reading up on the 1859 Carrington EMP Event. I assume flashlights without batteries are okay and shouldn't be affected, but protected batteries have chips in them. Can they be knocked out by EMP?

:wave:Also, how do Klarus batteries fare compared to other quality batteries?

THANKS!

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18650's of any make are a poor choice for long term storage in your bag. CR123A's or Energizer Lithium AA's are a far better choice.

"Long term" is very relative.
I don't see 18650s as unsuitable for bug out usage, especially if you're the type of guy/gal that'll review and test/cycle things a couple of times a year. Sure, there might be a loss of some of the stored energy, but they'd still be fine, and something as simple as a Nitecore F1 would allow you to charge them.
A few lithium primaries are nice as well though, in cases routines should slip, and because AA is such an available format.

terjee said:

"Long term" is very relative.
I don't see 18650s as unsuitable for bug out usage, especially if you're the type of guy/gal that'll review and test/cycle things a couple of times a year. Sure, there might be a loss of some of the stored energy, but they'd still be fine, and something as simple as a Nitecore F1 would allow you to charge them.
A few lithium primaries are nice as well though, in cases routines should slip, and because AA is such an available format.

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I agree. While they may not be providing 100% original capacity and certainly not ideal for high-drain lights, older 18650s still work. I have some 18650s from an old laptop pack, which was already worn down when I pulled them around 2014. The laptop was used from about 2007-2012. Pop them in a flashlight and you would think they were brand new cells. Of course, after handling a load they'll crap out earlier than a new cell, but still usable.

I set aside a bunch of randomly used cells, after charging to 3.92V and dating them. I'll be discharging them after something like 3, 6, 12 and 18 months, just to get a bit of an idea about useful power being available from them after sitting for a while.

I do routinely fully charge to 4.2V, and let them sit for months before they're rotated into use, with no significant issues.

It's true that Eneloops and lithium primaries are a better choice if you'll dump something on a shelf and might not use it for a few years, but LiIons are nowhere near as bad as pre-Eneloop NiMHs were, and can be quite usable indeed. Just depends on what your use case and expectations are.

Temperature and state-of-charge during storage are likely the two "controllable" factors with the greatest effect in this situation

Thank you for your replies.

I have a solar recharging system, so if things ever went truly South I could recharge the batteries. I just didn't know whether 18650 batteries could be stored without long term without degradation.

Years ago, a few friends and I went up the tram at Palm Springs to hike and camp overnight. I brought some items we needed, while someone else was in charge of bringing a flashlight. This fellow who was supposed to bring the light is the primary reason I'm into flashlights today. You see, he stopped by a hardware store on the way and bought a cheap flashlight from a bin. It had a shiny chrome body and a plastic head, and it came with two silver, cheap, non-alkaline batteries. There were no city lights up on the mountain, and at night temperatures dropped and wind was very cold. When this guy got out the flashlight -- the only one we had between us -- our hearts sank! The thing worked a good seven minutes, then began to dim! So here we are on a trail in the dark with no place to camp. The only light we had was the stars and this damn bargain bin flashlight, which we had to turn off, wait, then turn on again for about 40 seconds of dim light. It was so dismal that we considered resorting to human sacrifice, and the fellow who brought this cheap light was the prime candidate! We finally found a clearing amongst some rocks in the worst location possible. We started a fire, but we were on the high ground and the wind blew all night, and the heat from the flame went straight up. And what's worse, the guy who was in charge of bringing the light, had only brought a light blanket for himself, so we had to take turns using the sleeping bags and the inflatable cushions the rest of us had brought.

From then on, I made it a point to bring my own light, and I've never skimped. So I learned my lesson that cold night in 1972. It was one of the most miserable nights of my life, all because someone brought a cheap 99¢ bargain bin flashlight. If I had had only a Fenix E01 flashlight at the time, it would have saved us a world of hurt.

I salvaged a bunch of 18650 from lots of laptop battery packs, the cells are easily 10-15 years old by now.

I threw away tons of bad ones, the ones that don't hold charge but still ended up with around 100 cells that do, despite being that old.
I don't know what their capacity is, I am guessing around 2200 mAh if that. Probably even less. Still, they light up various devices I have fairly well if only for a short time. I've never really used them other than pulling a few misc one for more or less testing purposes. And yes they do work. In a single 18650 configuration being unprotected of course.

I see the place for these as a throw-away battery to keep the really good ones untouched, both 18650s and primaries. They aren't worth anything, are at the very end of their lives and should probably be recycled, yet 20-30 minutes from each 18650 times 80-100 gives you 30, 40-50 hours of full lumens from a Malkoff Hound Dog 18650. Certainly from the M61 module.
And the price was right, except it did take a while to take apart the cells and then remove the soldered on contacts.


I will go through the box again and throw again the ones that have dropped the voltage significantly after sitting for a year. Or not. If going on a trip, can charge a dozen or two and then just throw them away as used.

Here's an idea, kinda goofy but if it worked out it would be interesting.
Seal an 18650 in a watertight tube with a bit of desiccant, positive and negative marine grade wires coming out several feet, drop the tube into a PVC pipe buried several feet into the ground so the battery sits below frost line.
Maybe leave the tube open on the bottom and tamp a few inches of gravel in the bottom for drainage, maybe stick a few inches of foam rubber in the top for added insulation and put a cap on top.
Connect a small solar light to the battery, with the charge voltage limited to 3.6v or whatever your ideal storage voltage.
Limit the power of the LED so that there's only a negligible discharge per night, which can be regained by the panel daily under the worst conditions.

A little night light for a hunting cabin or something, pull the battery every few years and check it.

Somewhere between a pointlessly over engineered solar light light and a way to store lithium batteries long term off grid.

Now that I think of it a little more,
the effort involved seems more practical and worthwhile if it were scaled up so that a full replacement set of cells were stored this way, wired in parallel, with a better solar panel and brighter LEDs.
For instance, ten 18650, each charging and discharging 20 or 30 mAh a day and night, with a nice little 20-30 mA LED shining all night, every night.
Use a high power LED so that it's lifespan at 20-30mA is far beyond its rated life.

Other solar-powered devices exploit similar principles, e.g. recently I mentioned the use of ML2032 (Lithium Manganese dioxide) coin cells in solar keybooards. Just like Li-ion cells, they enjoy much longer life when you use very shallow cycles, which is often the case for typical keyboard use. Follow the link for further details, including precise numbers.

Nice, thanks for the input.
Here's a decent link to the geo tech, maybe not the best one possible, but good and quick:
https://www.builditsolar.com/Projects/Cooling/EarthTemperatures.htm

eh4 said:

Here's an idea, kinda goofy but if it worked out it would be interesting.
Seal an 18650 in a watertight tube with a bit of desiccant, positive and negative marine grade wires coming out several feet, drop the tube into a PVC pipe buried several feet into the ground so the battery sits below frost line.
Maybe leave the tube open on the bottom and tamp a few inches of gravel in the bottom for drainage, maybe stick a few inches of foam rubber in the top for added insulation and put a cap on top.
Connect a small solar light to the battery, with the charge voltage limited to 3.6v or whatever your ideal storage voltage.
Limit the power of the LED so that there's only a negligible discharge per night, which can be regained by the panel daily under the worst conditions.

A little night light for a hunting cabin or something, pull the battery every few years and check it.

Somewhere between a pointlessly over engineered solar light light and a way to store lithium batteries long term off grid.

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It sounds like an interesting project. Essentially, a solar garden light, but with the power supply buried. I'm not sure that's a good way to store lithium-ion batteries, unless you're trying to protect them from a nuclear blast, but it would be interesting to see if such a thing survives a winter or two. If nothing else, it would allow you to charge the lithium-ion battery safely during winter months, since the temperature under ground would be above freezing.

The main issues are spelled out in that hasty link I shared... I expected much more temp regulation from less depth.
I think that boring a hole would be best in most circumstances, rather than going at it with a shovel, and a (perfectly straight) digging bar, and post hole digger (I prefer a 1 quart pot held at arms length, thank you very much).
I think that if sufficient depth is found, that it will be a very good substitute for refrigeration... and the charge, discharge could be fine tuned for optimal lifespan.
Waterproofing issues are for the newbies, we can make it waterproof, and we can make the hole drain, and whatnot. Oxygen absorbers would be a nice addition for marketing purposes.

eh4 said:

The main issues are spelled out in that hasty link I shared... I expected much more temp regulation from less depth.
I think that boring a hole would be best in most circumstances, rather than going at it with a shovel, and a (perfectly straight) digging bar, and post hole digger (I prefer a 1 quart pot held at arms length, thank you very much).
I think that if sufficient depth is found, that it will be a very good substitute for refrigeration... and the charge, discharge could be fine tuned for optimal lifespan.
Waterproofing issues are for the newbies, we can make it waterproof, and we can make the hole drain, and whatnot. Oxygen absorbers would be a nice addition for marketing purposes.

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I think if your primary goal is storage, then it's probably better not to use the batteries as a power source at all. Just charge to 3.7v or 3.8v, bury them (or put them in the refrigerator because it 1000x easier) and forget about them for a few years. Good cells have such low self-discharge they will stay charged for many years. If they're in the refrigerator, it's also not too difficult to measure their voltage every year to make sure, and top up a bit if necessary.

Using them as a power source, even if it's just very small cycles, will probably cause them slightly more aging than not using them at all.

Mine are in the fridge.

eh4 said:

Mine are in the fridge.

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I generally wouldn't recommend that, unless you at least have a really good moisture management plan in place.

Its kind of got me thinking this(dangerous) But for a minute, you buy say a new 18650 light, be it a fenix pd35 or a kalrus........... You buy a nice sanyo 10a 3500 to feed it. Now typically this cell should last many years. Of course we cant put an exact, could be 3yrs, could be 7yrs..............heck could be 12yrs! Now other than "special" type lights, by that i mean a substancial investment or lights that can be upgraded(maybe p60 for one example). Not many will still be using that fenix or klarus 5-10yrs later. Some will, no doubt, but many would have gone for a newer LED, be it a jump from xml to xpl HI or xm-l2 to a nichia 219c as examples.

So a nice 90+ cri, nice 4000-5000 temp over a 70 cri 6500k(i know many still like cool white, this is just a general thought here as i know there will always be a good few who buy/own/invest differently).

So a typical 18650 cell of 2018, would quite possibly out live most modern lights(not just by them failing or gone bad, be it switch or LED /driver etc). I have 18650 cells maybe a decade old, the lights back then i would not use today due to horrid blues, no mode memory and .............well ones i had were mainly junk.

Maybe we will see the nichia as poor compared to newer LED's in 5-10yrs..............

terjee said:

I generally wouldn't recommend that, unless you at least have a really good moisture management plan in place.

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Seal them in plastic freezer bags. You can add some of those silica gel packets for added security. Though, just the freezer bags should be fine, as long as everything was dry when you sealed them up.

Overall, the refrigerator isn't that humid anyway. It's cooled by the air from the freezer compartment, which has very little moisture in it. It really only gets damp from humid air coming in when you open the refrigerator door. Or, if you have leaks from a poor design when the auto-defrost feature thaws the coils in the freezer. And, yeah, don't store the batteries in the vegetable drawer with a bunch of moist vegetables.

You probably don't need to refrigerate your cells, but it does help a bit to prevent aging from long-term storage.