if i lose power how many months will my 18650s stay charged to 80%

i hope it dont happen but i want to be prepared not sure if stocking up l91s would be better

~87 months.

The number is always 87.

Figure if they're charged up to 95%, you might lose 1-2% per year, storing in a climate controlled area and not you outdoor shed in Arizona.

Chris

ChrisGarrett said:

~87 months.

The number is always 87.

Figure if they're charged up to 95%, you might lose 1-2% per year, storing in a climate controlled area and not you outdoor shed in Arizona.

Chris

Click to expand...

awesume that made my night after this nightmare stuff on tv now. i have like 80 18650 cells btw the sonys sure have power. id guess they can give 30 amps if needed

raggie33 said:

awesume that made my night after this nightmare stuff on tv now. i have like 80 18650 cells btw the sonys sure have power. id guess they can give 30 amps if needed

Click to expand...

How many 18650 lights do you have, raggie33?

I have 6 lights that take 18650 and 10 cells, mostly IMR, but one INR, two ICR, with 6 more IMR cells on the way. I have trouble using up the capacity of my 18650 cells when I run them, but I sure use the heck out of my 18350 cells and my Eneloops.

chillinn said:

How many 18650 lights do you have, raggie33?

I have 6 lights that take 18650 and 10 cells, mostly IMR, but one INR, two ICR, with 6 more IMR cells are on the way. I have trouble using up the capacity of my 18650 cells when I run them, but I sure use the heck out of my 18350 cells and my Eneloops.

Click to expand...

just two. but im wanting to order a few more emsar dv42

raggie33 said:

just two. but im wanting to order a few more emsar dv42

Click to expand...

dv42 owners really love those, I keep hearing about Emisar. With as large a stash as that many 18650, you can just run those all day and all night all the time, as long as you have time to charge the cells.

I have enough 18650 lights, but I am speculating is the Noctigon KR4 with E21A. Hope the stock lasts until I am able to purchase.

chillinn said:

dv42 owners really love those, I keep hearing about Emisar. With as large a stash as that many 18650, you can just run those all day and all night all the time, as long as you have time to charge the cells.

I have enough 18650 lights, but I am speculating is the Noctigon KR4 with E21A. Hope the stock lasts until I am able to purchase.

Click to expand...

Emisar D4V2 vn quad W2 is one of my top favorite edc lights. I tack a small note to my 18650s, indicating the date and volts. When I check them a year later, I can see that they have lost very little charge. Same goes for both protected and unprotected. I like to rotate my edc lights and rotate my cells. I store plenty of cells on the back shelf at 3.6 volts, and I also keep plenty of cells at 3.9 volts, and I keep a few cells on the top front shelf at 4.1 volts.

richbuff said:

Emisar D4V2 vn quad W2 is one of my top favorite edc lights. I tack a small note to my 18650s, indicating the date and volts. When I check them a year later, I can see that they have lost very little charge. Same goes for both protected and unprotected. I like to rotate my edc lights and rotate my cells. I store plenty of cells on the back shelf at 3.6 volts, and I also keep plenty of cells at 3.9 volts, and I keep a few cells on the top front shelf at 4.1 volts.

Click to expand...

i trully love mine is sometimes makes me laugh how crazy bright it is

At 80% charged, the cells will be at around 4.0v. At that voltage, they lose almost nothing due to self discharge. They'll last years.

The question then becomes, how "healthy" are these cells. Even if they're around 80% after years, they may be degraded to the point where they won't be able to deliver the current you expect. And may not hold a charge very well after recharging.

I have a drawer full of 18650B, you know, when those were "the thing". I should do a test on some to see where they're at now.

Why would self-discharge damage Li-ion cells (so long as they don't drop bellow 2.5V)? What is the process that causes this alleged damage? Does high current discharge damage them? Then no or minuscule current aka self-discharge is ordinary, expected behavior, and shouldn't be a problem. I have heard this, too, that letting charged Li-ion sit is bad, and it just doesn't make sense, and I have never heard an explanation why this would be the case. IMO, as long as they're not over discharged, nor allowed to get too hot, nor dropped on hard surfaces repeatedly, nor punctured, nor shorted, they should be ok and still provide useable current up to the cycle limits.

markr6 said:

The question then becomes, how "healthy" are these cells. Even if they're around 80% after years, they may be degraded to the point where they won't be able to deliver the current you expect. And may not hold a charge very well after recharging.

I have a drawer full of 18650B, you know, when those were "the thing". I should do a test on some to see where they're at now.

Click to expand...

You'll probably find they still perform quite well, even after many years.

I don't have exact IR measurements, but I still use some 10+ year old laptop 18650's. They're Samsung 22F, and still have over 1800mAh capacity, compared to 2200mAh when new. They sat most of that 10 years in a laptop at 100% charged, not exactly good storage conditions. Their IR is probably higher than when new, but they still show a decent IR in my chargers (though I admit charger measurements are pretty inaccurate). They're about double what new Samsung 30Q's show in the charger, but again I'm not sure what that really translates to.

Those are genuine grade A Samsung cells, so they're probably better than many cells we get. But after 10 years, I'm surprised how well they held up. They're rated for 4.4 amp discharge, and still seem to perform quite well at 3 amps.

I think the alternative options vs 18650s cannot match them all around. Sure lithium primaries may not drop as much over the years as an 18650 and eneloops cannot match the power density even if they perhaps don't drop as fast in capacity over many years they still start at a huge disadvantage of it taking 4.5 2000mah eneloops to match the power of 1 3000mah 18650. At 80% the 18650 still has more power than 3.5 eneloops and during the time it takes an 18650 to drop to 80% the eneloop will have dropped to 80% or even less and that puts the 18650 back up to 4.5 times the eneloop again.
I too have a lot of laptop and tool battery 18650s and some discharge over a few years but probably because they are in cheap devices with electronics that may drain them. If you are concerned about having a good supply of power invest in some lower capacity 18650s for dirt cheap like 2000-2600mah they may have less capacity but when you have a dozen of them at 80% it is like having 10 of them fully charged in combined power. Even an 2000mah 18650 can match or beat 3 eneloops in performance and is easier to deal with.

Lynx_Arc said:

...they still start at a huge disadvantage of it taking 4.5 2000mah eneloops to match the power of 1 3000mah 18650.

Click to expand...

Not sure how this is a fair comparison. Lou Ferrigno, even at his age, can tie any tween into a pretzel with little effort. One Li-ion 14500 1000mAh cell just doesn't compare to a 1.2V NiMH 18650 4300mAh cell either. Eneloop blows away 14500 cells, and NiMH 18650 cells give Li-ion 18650 cells a run for their money. Apples to apples, brother.

chillinn said:

Not sure how this is a fair comparison. Lou Ferrigno, even at his age, can tie any tween into a pretzel with little effort. One Li-ion 14500 1000mAh cell just doesn't compare to a 1.2V NiMH 18650 4300mAh cell either. Eneloop blows away 14500 cells, and NiMH 18650 cells give Li-ion 18650 cells a run for their money. Apples to apples, brother.

Click to expand...

I don't think you have done the math. I have 800mah 14500 lithium ion batteries and at 3x the voltage they would match or beat any eneloop as 800x3 is 2400 and that would be the equivalent at 1.2v. A 1.2v 18650 at 4300 doesn't get close to a 3.6v 18650 at 3400, the 3400 18650 would have 3x the voltage making it essentially 10200mah equivalent at 1.2v.
The fact is lithium ion has higher energy density... and 18650 has one of the highest energy densities of cylinder type lithium ion cells.

Again it takes 3.... THREE nimh batteries in series to match the voltage of 1... ONE lithium ion cell so 3 4300mah 1.2v Nimh 18650s would have 900mah more capacity than a SINGLE 3400mah 18650.

Consider also that your 14500 may only see 500 cycles while the Eneloop will see 2100+. But if you wish to ignore this, then an Eneloop Pro 2500mAh does indeed eek our a victory over the same sized Li-ion and with the same number of available cycles.

The reason an 18650 NiMH only has 4-5000mAh is that they just aren't popular. If they were made like Eneloop at FDK, perhaps we would see something. So look at a NiMH LSD D cell with 10,000mAh, compare to Li-ion D sizes, and get back to me. Might be easier to find a C sized Li-ion for comparison. NiMH LSD C sizes have 4500mAh.

Li-ion is certainly good, but I think it was more amazing when it was novel in the early-mid 00's, and flashlighters from that era that got their hands on one were probably very happy. But Li-ion capacity advancement since has not been in leaps and bounds, but in small increments, and recently largely thanks to Tesla electric vehicles. I think the more recent killer advancement in battery tech goes to Eneloop... so I am to them like the flashlighters from the 00's were to Li-ion.

Also, not for nothing, the output curves of Li-ion are disgracefully near 45° diagonal lines, while NiMH output curves are so flat, they have often been referred to as "battery regulation." It would be great if Li-ion output curves could aspire to that kind of flat output around one voltage rather that so directly dropping from 4.2V down to 3.6V.

chillinn said:

Consider also that your 14500 may only see 500 cycles while the Eneloop will see 2100+. But if you wish to ignore this, then an Eneloop Pro 2500mAh does indeed eek our a victory over the same sized Li-ion and with the same number of available cycles.

Click to expand...

Not really as I quoted an 800mah 14500, and there may be 850-900, even (as you mentioned) 1000mah 14500 which means MORE power than a 2500 Eneloop Pro. The big disadvantage of Eneloops is the lower voltage hampers their performance vs a 14500. It takes at LEAST 3 times the current from an Eneloop to match the same output from a 14500 which often can lead to power loss in use in higher output devices using a single cell. The only way to overcome this is to go with multiple Eneloops in series which with lower power density cannot compete with an 18650. A single 14500 probably costs around the same as 3 Eneloop Pro cells and Eneloops in series has a risk of overdischarging cell(s) in series causing damage to them while a single lithium ion has no issues.

The reason an 18650 NiMH only has 4-5000mAh is that they just aren't popular. If they were made like Eneloop at FDK, perhaps we would see something. So look at a NiMH LSD D cell with 10,000mAh, compare to Li-ion D sizes, and get back to me. Might be easier to find a C sized Li-ion for comparison. NiMH LSD C sizes have 4500mAh.

Click to expand...

I've heard 32650 (D size?) and 26650 cells are not quite as dense as 18650s but should still have at least DOUBLE the power than the best LSD (or other nimh) cells of the same size. Nimh is nowhere near as light and nowhere near the power density that is why where we used to have nimh based cell phones and power tools (for a short time) that are now replaced by lithium ion batteries.
I've gone to 18650s over nimh on most things because I've had LSD nimh cells damaged in series in devices and having to juggle 2-4 nimh cells vs a single 18650 or multiple ones in parallel is no contest. I once entertained buying a nice 3AA LED light but after I got an 18650 light and headlamp that blows away any 3AA lights and even 4AA ones my eneloops (duracells) are mostly sitting in devices.
I've had poor luck with LSD AAAs even Eneloop varieties have either got damaged in series use or over time lost capacity and developed high enough internal resistance the LSD was no longer Low.
I don't really see Eneloops catching up nor winning against 18650s. About the only 2 things they have going for them is safety and use along with and in AA powered devices.

Li-ion is certainly good, but I think it was more amazing when it was novel in the early-mid 00's, and flashlighters from that era that got their hands on one were probably very happy. But Li-ion capacity advancement since has not been in leaps and bounds, but in small increments, and recently largely thanks to Tesla electric vehicles. I think the more recent killer advancement in battery tech goes to Eneloop... so I am to them like the flashlighters from the 00's were to Li-ion.

Click to expand...

I see Eneloops still useful but more and more people are drifting away from them as a major power source to lithium ion 18650s and such.
The sad thing is I don't think you can hardly find them in stores even under a different label now which was a major selling point and you can no longer find single cell/channel chargers in stores for them which is a major drawback. You have to order Eneloops, decent chargers for them just like you have to do for 18650s now. I don't care for the pro's that much I haven't used but a pair of them since I have them but my transition to 18650 as my primary power source has them idling in some light somewhere.
Let's face it for Eneloops to gain market share they need a breakthrough or huge local sales support for them. All the power banks use 18650 or some other lithium power source now for a reason. I think the next advancement in lithium ion will probably be safety related.
I seriously doubt nimh tech will go anywhere as 1.2v cells are just not attractive power source now for todays electronics.
USB and lithium ion go together very well and rule the rechargeable world in most situations.

Looks like the OP's question has been answered and this 18650 thread is now about Eneloops. If there is nothing else on topic to add we can probably let it wrap up.

I agree not much else to say here.

While 18650 is a grey format I do like single AA lights for emergency. Can run off NIMH, L91 or even a AAA if needed.

Always good to have more than one cell format available because in a widespread disaster it may be hard to get certain types.