# Are your old Eneloops still going strong? - a survey.



## shelm (Jan 6, 2012)

Hello everybody,
just curious to know. The very first Eneloops to see the world were introduced in *Nov 2005*, which took place in Japan. Shortly after, in spring 2006, they were distributed world-wide and by Nov 2011 have reached their 200,000th sale and this is being celebrated by the November 2011 Japan release of the _Eneloop Tones Chocolat_. In spring 2012, the Chocolat Eneloops and the white standard Eneloops will hit _international _release as HR-3UTG*B* and HR-4UTG*B* for the 3rd generation Eneloop AA and AAA cells.

So, the oldest Eneloops anyone could possibly own are *exactly 6.0yrs old* (and those cells bear the model number HR-3UTG and HR-4UTG)!

Survey: How old are yours, how intense have you use been using them, and what is your estimated degree of cell quality degradation ("aging")? -- Users with hobby chargers, Powerex C9000, or the cloned/rebranded BC-700 (BC-900, BC-1000, etc.) could tell exactly what the mAh-capacities of their Eneloops are after all these months and years of high-power Cree LED flashlight abuse 

Thanks in advance for some rambling on your Eneloops


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## SilverFox (Jan 6, 2012)

Hello Shelm,

Welcome to CPF.

I am still using a lot of the original 2006 Eneloops and they are still going strong. I believe I still have an unopened pack and I should see if I can find time to run some tests on those cells.

Tom


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## Steve Cebu (Jan 6, 2012)

My Eneloops are 4 years old. I use them in my Nitecore D10 and a Fenix L01 I believe, as it's my wife's EDC and I never see it anymore. 
I also use them for a lot of stuff around the house. I don't use them in anything where they might get tossed out or in my remote controls.
They have held up really well. I will be buying 16 of the newer ones next month.
I recharge them with a Lacross BC-900 which is also 4 years old.


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## uk_caver (Jan 6, 2012)

I've been using a decent number of Eneloops since shortly after they came out, and I haven't had any cell-related problems (apart from a couple of AAAs that eventually got killed (presumably by unfriendly charging) in a cordless phone handset, which I don't think counts as an Eneloop issue since it has happened with other cells as well.

My expectation is that most of my cells will be going strong for many more years, which is more than I could say for the various >=2300mAh NiMH cells I have had (and ended up trashing) over time, and that I'm probably more likely to lose Eneloops (or have them 'borrowed') than actually wear them out.


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## Glock27 (Jan 6, 2012)

My oldest Eneloops are from February of 08. I bought a Maha C9000 charger at the same time. All my Eneloops and Sanyo 2700's are still going strong!
Good cells AND good charger = great results.

G27


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## Aquanaut (Jan 6, 2012)

Only slightly off topic, but I bought my Imedion 2100 mAh batteries on 12/17/07 and recently discharged them on a C9000 @ 500 ma. They had capacities of 2019, 2024, 2032, and 2012 mAh.

First I did a discharge/charge at 240/500 ma on a Maha C204F and the batteries were luke warm to the touch. Then I did the capacity test on the C9000 the next day.

I believe that it was Mr. Happy who said that it is good to warm up the batteries during charging to redistribute the electrolyte. I believe in this observation. Charging on the C9000 does not warm up the batteries.


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## bruintennis (Jan 6, 2012)

Great to know that eneloops have stood the test of time! Great product.


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## Papuga (Jan 6, 2012)

All but 3 of my original purchase of 40 are still going strong. They still test out at over 1850 mah on the C9000 and still do very well on the CBA. These were all purchased in 2006. Quite impressive product.


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## Wrend (Jan 6, 2012)

My oldest Eneloops are the first generation ones from about two and a half years ago. They've had a pretty low cycle life so far (probably somewhere around 50 cycles, or so), but have gotten rather toasty on "dumb" chargers, and have been subjected to 5 amp drain rates a few times.

The last time I tested them a couple of months ago on my C9000, they're 1.1% lower in capacity on average than the average of new Eneloop cells.


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## DoctaDink (Jan 7, 2012)

I've a bunch of the old HR-3UTG eneloops that I've used multiple times to power Nikon SB-800 flashes, various flashlights and other devices and they just keep on going and going and going. Love these things!
(I Charge them with a Maha MH-801D)


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## Bozzlite (Jan 8, 2012)

I have four that I purchased in '07 and 4 that I purchased in '08. I don't have the tools to measure capacity, but they are all performing well in my flashlights and digital camera. Still very low self discharge rate. The only problem I've had with them is the wrapper has become slightly soft and tacky and is starting to peel. A bit like a sunburn peel.

All the Energizer and Powerizer non LSD batts I had in '06 and '07 have failed one way or the other and were sent to the recycle bin a couple of years ago.


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## itguy07 (Jan 8, 2012)

I'm going through a checking and thinning if my AA batts, many of which have been severely neglected, abused, and otherwise not treated right. Last time I ran many of them through the Maha C9000 was 2007. Some have been cooked on the 15 minute Energizer, 1 hour Ray O Vac or left to charge in a 25ma dumb charger for weeks at a time.

The Eneloops that have an 06 date code seem to be doing the best:


BatteryCapacity%Eneloop AA #22001100.05%Eneloop AA #3190095.00%Eneloop AA #42019100.95%

I've got about 4 more to cycle through the C9000.

Have recycled a bunch of Tenergy 2600 Mahs that show either "HIGH" or low (less than 40%) capacity, a couple Duracell 2300s, as well as an Energizer 1800 here and there.


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## budynabuick (Jan 8, 2012)

2 months ago i opened a couple packs that were at least 3 yrs old (they were supposed to be the latest). I bought 4 packs and 2 were the latest and 2 were old stock which i started 2 send back but decided 2 avoid the hassle and the old ones still had 75% charge thus confirming these do indeed hold their charge after 3 or more years and are working like new! Great product that delivers as stated. 

Keith


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## Wrend (Jan 8, 2012)

> ...the old ones still had 75% charge...



That's impressive. They leave the factory 75% charged.


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## arjay (Jan 9, 2012)

Those readings are odd, my 1st set of 4 eneloops which I got around August of 2006 are showing 1550mah to 1500mah in capacity according to the C9000 and one displays High. Well they have been abused like draining them down in lights on high till no light would be produced, no refresh every couple of months. I know that they were recharged twice to three times a week at some point so that might be a big factor. They have served me well over the years and have maybe close to 250-300 cycles on them so I can't complain. They still hold their charge well too and have been moved to my "reserve force".


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## Rossymeister (Jan 9, 2012)

I Had A Set Of 8 from Around 2007. Unfortunately i Had To Throw The Majority Of Them Away Because The Anodes And Cathodes Were Dented In Pretty Badly. I Didnt Have Any Problems With Capacity Or With Them Holding A Charge However.


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## jayflash (Jan 9, 2012)

My batch of 30 AA & AAA Duraloops from 2008 are embossed with 7004 + letters, so I'll assume they're from 2007. All still indicate about 1900mAh & 800mAh, respectively, at 500mA & 250mA load on a BC-900. I charge them at 1000mA & 500ma and try rotating so they get used. Even those left in little used devices for one year had about 80 - 90% capacity left.

I've also a batch embossed with 9k21-ur & 9h11-eh, which I'll guess are from '09 and purchased in 2010. All are good.

It's interesting that out of 50 "surplus" 1200mAh NiMh cells from Singapore, purchased in 2001, half of them still work and have about 800mAh capacity remaining. They still have fair storage life, but suffer reduced voltage (1.15 -1.20v) under 500mA load. I paid only 50 cents each and didn't have a smart charger until 2005. These have been abused.


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## jasonck08 (Jan 9, 2012)

Yes, my oldest ones are from 2007 or 2008 and they still provide about 1900mAh. However, I had one cell that somehow managed to discharge itself to 0.01v and now its not performing quite as well, even after a few cycles. But no big deal its only one cell.


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## davidV5 (Jan 10, 2012)

My oldest ones are from 2007 and are still going strong.

Off topic, my oldest GP Recyko are also from 2007 and are also going strong.


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## Derek Dean (Jan 11, 2012)

I've got four HR-3UTG AA cells, and four HR-4UTG AAA cells, all from that first batch in either late 2006 or early 2007, along with the Sanyo NC-MDR02NU two bay charger that I've used to charge them. They all still work fine and have been used more or less continuously this entire time, in my Fenix LD2 (which is my bicycle commute light) and in various keyring and pocket lights.

I have followed the directions I got from Battery University and have fully discharged the cells once or twice a year (to reform them), while topping them off once every two or three weeks the rest of the time (just the ones that are getting used).

Talk about a product that has FULLY lived up to and surpassed my expectations! Way to go Sanyo!


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## illumiGeek (Jan 13, 2012)

itguy07 said:


> ...The Eneloops that have an 06 date code seem to be doing the best...


They have a date code? I guess it's like the horse said, you learn something new every day.

I have a bunch of older style Eneloops, and I tried testing them once to see if I could sort the older ones from the newer ones, but they all tested within a few percent of each other, in spite of some being almost new, and others several years old. After reading about a date code in the post above, I took a look at my white Eneloops, but still did not find anything? So I went to the great oracle of wisdom (google) and found the codes. Dayum it's hard to see (then again, I'm quite far sighted).

Anyway, to make a short story long...

With the help of my trusty Fenix L1T V2 R2 (and some strong reading glasses), so far I have found:

8 from 2006 (06 07TA)
8 from 2007 (07 08TL) ** The 07s are _*really*_ hard to read!
8 from 2008 (08 08ER)

So that's 24, from 3 successive years. Probably have more somewhere (I have way too much battery powered crap, lol!). I just popped 4 of the the 2006 cells into my BC900 for testing. We'll see if they still test like new. Many of these have been cycled hundreds of times, and most have been in high drain hotwire mods and diving lights (often sucked dry). They've usually been charged on my LaCrosse BC900 or Maha MH-C9000 & MH-C801D. A few have been run through an Eveready 15 minute battery cooker, but not very often.

The only Eneloops I have that I _know_ have lost some capacity were the "Duraloops" that were in my LaCrosse BC9009 when it went into melt-down mode. But even though they got too hot to touch, they still work to this day, and last I tested them they had around 1650-1700mA capacity. Three of those are in my PS3 Sixaxis controller (which I use with my PSPgo now), and I don't recall where the 4th one went (probably in a clock).

I wonder how old the rest of my Duraloops are? I've got quite a few of those as well. And I've also got a bunch of the newer 1500 cycle 'loops.

Anyway... I'll test my 2006 cells and report back.

EDIT: First test pass complete!

LaCrosse BC900 (v35): Charge/Test mode (1000mAh charge, 500mAh discharge)
Eneloop AA cells from 2006 (06 07TA)

1=2060
2=2050
3=2040
4=2030
5=2020
6=2000
7=1651 *
8=1590 *

Not bad results! Six out of eight 5.5 year old batteries still testing at or above their new factory specifications. The last 2 cells tested below spec so I am running a break in cycle on my C9000 and then I'll re-test. UPDATE: re-sorted by capacity, and break in still running on low cells (really slow process).


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## illumiGeek (Jan 21, 2012)

Okay, final verdict. Several attempts to resurrect those weak cells failed. Ran refresh cycles on both the Maha C9000 and LaCrosse BC900, and also tried a break in cycle on the C9000. Final test pass on the BC900 showed their capacity at 1702 & 1572. So it appears that 2 out of 8 of my 5.5+ year old Eneloops are showing their age. However, 6 still test over 2000mAh capacity, which is within the specifications for new cells (1900 minimum, 2000 typical).


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## shelm (Jan 23, 2012)

illumiGeek said:


> BC900 showed their capacity at 1702 & 1572


So what does this mean in practice, what's the advice here?

( should we dispose the two cells?, or would it be waste to do so? )


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## SilverFox (Jan 23, 2012)

Hello Shelm,

I generally retire cells when they fall below 80% of their initial value.

Eneloop cells start off at around 1900 mAh. 80% of that is 1520 mAh.

Tom


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## shelm (Jan 23, 2012)

Good rule of thumb, thanks!
If we take normal care of our Eneloops (e.g. topping off the unused cells on the 1st of every month, i.e. 12x per year; and a break-in with these unused cells 1x per year), they should not be aging until years later, am i right?

That's the whole purpose of buying Eneloops (=top quality cells)


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## n3eg (Jan 23, 2012)

uk_caver said:


> a couple of AAAs that eventually got killed, presumably by unfriendly charging in a cordless phone handset, which I don't think counts as an Eneloop issue since it has happened with other cells as well.



Interesting - my only bad Eneloop cell was in a homemade pack for a cordless phone. My big Eneloop torture test is a set of Duraloops in a two-way radio battery that is used 5 days a week since last February and charged at 0.5C every night - so far, no loss in runtime.


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## illumiGeek (Jan 23, 2012)

shelm said:


> So what does this mean in practice, what's the advice here?
> 
> ( should we dispose the two cells?, or would it be waste to do so? )


I hang on to cells that still have usable capacity. Those 2 will probably go into things that don't need much current (clock, mouse, keyboard, etc.).



shelm said:


> Good rule of thumb, thanks!
> If we take normal care of our Eneloops (e.g. topping off the unused cells on the 1st of every month, i.e. 12x per year; and a break-in with these unused cells 1x per year), they should not be aging until years later, am i right?
> 
> That's the whole purpose of buying Eneloops (=top quality cells)


Why bother "topping off" LSD cells? The "whole purpose of buying Eneloops" is that they don't need to be topped off.


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## Trancersteve (Jan 23, 2012)

illumiGeek said:


> I hang on to cells that still have usable capacity. Those 2 will probably go into things that don't need much current (clock, mouse, keyboard, etc.).
> 
> 
> Why bother "topping off" LSD cells? The "whole purpose of buying Eneloops" is that they don't need to be topped off.



Because they aren't zero self discharge cells?

Personally, I top up my 'standby stash' after between 3-6 months depending on the brand of LSD cells.


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## Wrend (Jan 23, 2012)

I don't bother topping of my Eneloop cells once they're off the charger. They self discharge so slowly that it isn't worth the effort for an insignificant amount of longer run time, and perhaps even more importantly, I match all my cells and only use them in series cell sets that get charged and used at the same time in the same devices together, so they remain equally charged as each other and wear evenly.

The self discharge rate of Eneloops decelerates over time, so they lose a higher percentage of capacity initially. So the difference in charged capacity from 0 to 3 months is going to be greater than from 3 to 6 months, and from 0 to 1 year than 1 to 2 years.

The main reason to top off cells (on an independent port charger) would be if you don't know how fully charged they are compared to each other. This would probably add less wear on the cells than using ones together that don't have the same amount of charged capacity.

To keep your cells in top performance (again, not really an issue for me) a slow discharge followed by a full charge would probably be even better, though it may add some wear to the cells.


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## illumiGeek (Jan 24, 2012)

Trancersteve said:


> Because they aren't zero self discharge cells?


No, but their discharge rate is so slow that topping off frequently makes no sense. You gain what, an extra 100mA? Unless you have reserve Eneloops that are _never_ being used -- in which case I'd suggest you rotate your cells -- or at most, top off once a year (anything more frequent than that is just a waste of time and energy, and probably causes pointless wear on the cells).

I rotate cells. When I pop spent cells onto a charger, I take some out of my charged reserve to replace them. As cells come fresh off the charger I put them into the reserve case upside down from the others, so that I can tell which need to get used next. Once the whole case is flipped I turn them all over and repeat. I also always pull from right to left which helps to keep things pretty even.

The 2 cells I have that are weak were in my Bluetooth mouse, which is charged on a cradle that has a series "dumb" charger. I didn't rotate those since the mouse had its own charger, but in retrospect, maybe I should have? Then again, they did last over 5 years, even with the abuse.



Wrend said:


> I don't bother topping of my Eneloop cells once they're off the charger. They self discharge so slowly that it isn't worth the effort for an insignificant amount of longer run time


Agreed!



Wrend said:


> ...and perhaps even more importantly, I match all my cells and only use them in series cell sets that get charged and used at the same time in the same devices together, so they remain equally charged as each other and wear evenly.


I don't even bother with that. Look at my test figures above. Not counting the 2 cells from the mouse (which weren't in rotation) the difference is only 3% from the best to the worst. That's probably close enough to be considered margin of error. It's certainly close enough that I don't worry about balancing. When I tested all 24 of my Classic (Retro?) Eneloops a couple of years ago the difference was less than 100mA (<5%).



Wrend said:


> The main reason to top off cells (on an independent port charger) would be if you don't know how fully charged they are compared to each other. This would probably add less wear on the cells than using ones together that don't have the same amount of charged capacity.


I do that before filling my two 8 cell HID dive lights, but that's because I usually don't have 16 cells in my charged reserve and have to pull cells from other devices.

Currently I have 11 'loops in my charged reserve, and 47 in use in various devices. That's a total of 58 Eneloops. 24 "Classic" + 8 "Duraloop" + 26 "1500" types (and that's just the AA size).

Is that a lot?


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## CandleLite (Nov 6, 2017)

I have 20 or so AA Eneloops that I have been using for a while, so I thought it was time to consider if I should replace them. A closer look revealed that they were all 1st Gen with dates around 06-0715 and 08-0600. So this means that these batteries are 9 to 11 years old and have been in continuous use for the past decade. They are spread out throughout the house in many applications like flashlights, remotes, mice and even a milk frother. I would not consider anything was of heavy use other than my Magic Mouse which burns through batteries.
I recharge them as necessary in my La Crosse BC-900 and apart from the occasional refresh they still take a 1900 or 2000 Mah charge. Some go to 2100 Mah. I have never had to discard a single Eneloop yet and it seems like there are still many cycles left in them.

Is this typical or am I just lucky? 

I just ordered another 8 of the 4th Gen batteries because the electronic devices and flashlights have multiplied around here. I hope they give me a similar performance and longevity.


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## bigfoot (Nov 6, 2017)

CandleLite said:


> Is this typical or am I just lucky?



LOL, had to chime in -- pretty much mirror your experiences here, right on down to the milk frother and La Crosse charger! 

Earliest cells on this end are from Aug. 2006, and they are all still going strong. (Although I use newer Eneloops in higher drain devices like GPS, radios, etc.)

Just imagine what not buying alkaline batteries for over a decade has saved! :thumbsup:


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## martinaee (Nov 6, 2017)

Not sure if i have older than 2010 Eneloops, but I do have a bunch labeled "2010" in sharpie that are still great so they do last a long time.


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## SilverFox (Nov 7, 2017)

Hello CandleLite,

I just recently retired some of my first generation Eneloop cells. They were used in a camera that didn't get much use. I think the lack of constant use just did them in. I have a few more in flashlights and they are still going strong.

Tom


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## terjee (Nov 7, 2017)

SilverFox said:


> I just recently retired some of my first generation Eneloop cells. They were used in a camera that didn't get much use. I think the lack of constant use just did them in.



I’m curious... 

What made you decide it was time for them to go?

And did you try putting them through a refresh cycle?

Hope you don’t mind me asking.


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## Hugh Johnson (Nov 7, 2017)

I have some IKEA Ladda 2450, which I heard are arguably rebadged eneloop pros. One of them doesn't hold much capacity after a few cycles. This makes me want to invest in some regular eneloops.


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## SilverFox (Nov 7, 2017)

Hello Terjee,

On a Break In cycle they came in at 900 mAh of capacity. In addition they seem to have lost their low self discharge capability. I would put the cells in the camera and on about the second use within a couple of weeks the voltage would drop low enough to shut off the camera.

Tom


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## WDG (Nov 7, 2017)

My oldest Eneloop AAs are from around July 2007, and my newest are from around November 2008. All 2007 cells are high-resistance, and about half the 2008s are, also. There seemed to be a difference between the two sets in how long that took to happen, with the 2008s lasting longer. My normal-resistance 2008s range from around 900mAh to around 1500mAh remaining capacity. Not bad, IMHO. 

I continue to use high-resistance cells in low-draw devices until the old C.Crane charger turns up its nose at them.


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## filibuster (Nov 7, 2017)

WDG said:


> ...I continue to use high-resistance cells in low-draw devices until the old C.Crane charger turns up its nose at them.



I might be time to retire your old C.Crane charger. If it's the old quick charger like the one I have it was made for old NiCd and NiMh cells that needed a trickle charge to keep them topped off until you pulled them out of the charger. The eneloop and newer LSD type NiMh cells don't need a trickle charge and as I understand it, a trickle charge can degrade their performance over time. I wonder if that's why you are seeing the high IR on your eneloop cells?


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## filibuster (Nov 7, 2017)

I just did a test on a pack of 10 year old 1st generation eneloop cells I had in storage. They were dated July 2007 on the cells. 

Straight out of the package I did a discharge test and they showed a capacity of just over 1100mAh @ a 400mA discharge, which means they held onto over 60% of their original 1900mAh capacity after 10 years of sitting on my basement shelf.

After a few charge discharge cycles they tested to just over 1800mAh during a 400mA discharge meaning they've only lost about 5% of their original capacity after 10 years of storage.

From the looks of things, it appears if you use them or store them you can expect to get 10 years and beyond of good life out of these eneloop cells!


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## tatasal (Nov 7, 2017)

I have similar experience with my Eneloop AA and AAA. Great cells I should say.

Avoid the Powerex Imedion AAs....all 16 of them that powered my Fenix TK41 and Nitecore EA8 are now all junk, some of them even leaked!


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## terjee (Nov 8, 2017)

SilverFox said:


> On a Break In cycle they came in at 900 mAh of capacity. In addition they seem to have lost their low self discharge capability. I would put the cells in the camera and on about the second use within a couple of weeks the voltage would drop low enough to shut off the camera.



Many thanks!

Always interesting to learn about what it looks like when reliable things start to give in.


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## GaryF (Nov 8, 2017)

Eneloop’s are one of the best investments I ever made, still have a bunch from 2006 and 2007 going strong. My only failure was one that got a little bit crushed in transport. 

i recently bought 16 of the current generation to use in 3AA to D cell adapters in a vintage radio.


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## Kurt_Woloch (Nov 11, 2017)

I basically have Eneloops from two batches... 4 AAA cells I bought in 2010 and 12 AA cells made in April 2014. Out of the AAA cells, 3 have been badly impacted by use in a cheap wireless phone which did some heavy trickle charging to them, the 4th one should be OK. I'm now using two of the badly impacted 3 in the remote of my robotic vacuum whose batteries recently died, where they still seem to work good enough.

The AA's have been spread among various devices... currently, 6 are in my musical keyboard, 2 in a wireless microphone, 2 in a portable CD player and 2 in a toothbrush I bought yesterday to replace an Oral-B Vitality brush whose built-in battery died after nearly 7 years of use. So far none of the AA's have let me down.


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## tandem (Jan 2, 2018)

In 2010 I started accumulating quite a few Eneloops / Duraloops and some Imedions - more than 100 cells and almost all are continuing to see regular use. So far I've only had to toss a couple AAA Duraloops.

It's time to run them all (when time permits) through a refresh cycle; I've only got one C9000 that I use for that so it'll take a long time ;-).

I plan on buying some 4th gen cells if I can't find where some of my stash have wandered off to, not because the Gen 1 cells are not usable.


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## ChibiM (Jan 2, 2018)

tandem said:


> In 2010 I started accumulating quite a few Eneloops / Duraloops and some Imedions - more than *100 cells* and almost all are continuing to see regular use. So far I've only had to toss a couple AAA Duraloops.
> 
> It's time to *run them all* (*when time permits*) through a refresh cycle; I've only got one C9000 that I use for that so it'll take a long time ;-).
> 
> I plan on buying some 4th gen cells if I can't find where some of my stash have wandered off to, not because the Gen 1 cells are not usable.


Good luck!


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## Bazsy (Jan 3, 2018)

I have 8 AA std Eneloops from around 2007-08. They are were used in a handheld GPS and in some AA flashlights and in a digital camera. Only one died by getting a sky-high IR for some reason. The rest is still going strong and having their stated capacity. I have also 8 AA Eneloop pros from the second generation. Those are used in a camera flash and also baby monitor and work just great.
I have recently bought 8 std and 8 pro AAs and 8 std AAAs from the latest generations from Japan and this might be enough for the next 10 years


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## tandem (Jan 3, 2018)

I did a C9000 refresh/analyse on the first four cells at hand, a mixed bag of cells - one Amazon Basic (2 years old), one Imedion (7 yrs), one Duraloop (7 yrs), one Eneloop (3 years). The Duraloop, AB, and Eneloop all turned out with similar capacity reported by the C9000 using 0.5A charge and discharge ~ 1850mAh. 

The Imedion reported only 220mAh usable capacity. I may do a refresh on that one just to see if that's real... but I suspect it's real. I have so far only tossed AAA and AA Imedions from my 2010 era purchases and probably have enough data points on that ... to discourage me from ever buying them again. That may not be fair given things change over the years.


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## WalkIntoTheLight (Jan 3, 2018)

I went through and counted up all my Eneloops I think I have. 384. Yeah, way too many, and I might have missed some in a device or two I've forgot about. About half of them I've never used yet. Of all the rest (including some from 2006), none have failed me yet. One of the 2006 cells is showing its age. A few more have reduced capacity because I cooked them in a light that gets too hot. I have reverse-charged a couple of them (drained flat in a multi-cell device, with a cell getting a small negative voltage), but they show no ill effects of it.

I generally take good care of them. I usually charge them slow, on chargers that terminate reliably and don't trickle-charge. I think the most any of them have been cycled is probably 300 or 400 times, but probably not even that much. So, the biggest issue most of them face is age. But so far, they're holding up very well. Way better than any other brand I've had in the past (but I've only bought Eneloops for the past 10 years).

I usually charge at least 16 cells per day, so they get a lot of use. But that use is spread out over a lot of cells.


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## Dragracer (Jan 3, 2018)

My first gen Eneloops from 2009 still have ~1750mAh, but a slightly higher internal resistance. But still good for the digital camera. 
My 2nd gen Eneloops from 2010 are like new.


5 Years ago I put 4 Eneloops 2nd gen in a handheld vacuum cleaner instead of Sub C NiMh.
They are drained with 5A all the time and still are like new.
The original Sub Cs were dead after 3 years...


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## MidnightDistortions (Jan 6, 2018)

I've only had Eneloops for about 4 years. My AAA Eneloop Pro batteries had 90% IR, but I cycled them a few times and now only have about 30% IR. Weird.


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## Bazsy (Jan 6, 2018)

MidnightDistortions said:


> I've only had Eneloops for about 4 years. My AAA Eneloop Pro batteries had 90% IR, but I cycled them a few times and now only have about 30% IR. Weird.



Do you mean mOhm? % is not really a good way to describe IR.


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## MidnightDistortions (Jan 6, 2018)

I get IR readings from the C9000 charger.


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## MrMorden (Jul 27, 2018)

I just found a 4-pack of AAs, first-generation, NIB in a box of random batteries at home. I'd have purchased them in the UK; the date code on the package is 2008-02.

I threw them on a BQ-CC55 and it showed < 20% power. Which I guess shouldn't be surprising. Maybe I should've listed them on fleaBay ([email protected]@K!!! RARE!!!), but it's too late now.


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## WalkIntoTheLight (Jul 28, 2018)

I did some discharge tests on old Eneloops (12 years old, I've used since 2006), and some new Eneloops (bought a couple of months ago, did 2 cycles to refresh them).

The results:

Average of eight 12-year old AA Eneloops: 1852mAh
Average of four new AA Eneloops: 1972mAh

That's a 6% loss of capacity, assuming the old Eneloops had the same initial capacity as new Eneloops (tested after the 2nd cycle).

Test was done at 250mA drain. It's not testing how well they perform under high-drain usage, but I have occasionally used them in high-drain and they still perform fine. Their internal resistance is higher than new cells, so they probably have lost quite a bit more than 6% at high load. Still, for regular use, it's pretty good to lose only 6% capacity after 12 years!


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## MrAl (Jul 31, 2018)

Hello there,

Circuit City closed up around 2009 and before that i remember seeing some of the first Eneloops being sold in one of their stores but they were 20 dollars (USD) for just four cells so i thought that was overpriced and did not buy them.
Shortly after that though i did buy some at another place, cant remember where though.
That means my oldest cells had to be around 8 years old last year, when i threw some of them out.
The only reason i threw them out was because one of my Panasonic chargers started to reject some of the cells, about 4 of them. This was probably due to higher internal resistance but i did not check that at the time.

I still rate them as one of the best cells i have ever owned however. In comparison, i have had Energizer high capacity cells that i used maybe three times and then chucked them right into the garbage. I also had Energizer AAA cells that i threw out, wrote to the company and got a coupon for four new ones, then threw them out too because they did not hold their charge for more than a week if that.

So Enerloops have my highest rating. I did find other cells that have low self discharge too, but i dont see them around anymore.
Of the Eneloops i have tested so far they all measure around 2000mAHr.


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## WalkIntoTheLight (Jul 31, 2018)

MrAl said:


> That means my oldest cells had to be around 8 years old last year, when i threw some of them out.
> The only reason i threw them out was because one of my Panasonic chargers started to reject some of the cells, about 4 of them. This was probably due to higher internal resistance but i did not check that at the time.



Yes, that's how they determine if a cell is old. Actually, they are likely trying to determine if the cell is an alkaline, which should not be charged. Alkalines have higher internal resistance than NiMH.

What charger were you using? I find that the Panasonic BQ-CC17 chargers will all still charge my old 12-year Eneloops. They won't charge other old NiMH cells, which have developed extremely high internal resistance. But the Eneloops still keep on chugging along.


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## MrAl (Jul 31, 2018)

WalkIntoTheLight said:


> Yes, that's how they determine if a cell is old. Actually, they are likely trying to determine if the cell is an alkaline, which should not be charged. Alkalines have higher internal resistance than NiMH.
> 
> What charger were you using? I find that the Panasonic BQ-CC17 chargers will all still charge my old 12-year Eneloops. They won't charge other old NiMH cells, which have developed extremely high internal resistance. But the Eneloops still keep on chugging along.



Hi,

Yes i think the CC17 would work, but i was using the CC55 which charges with higher current. Maybe i threw them out too soon, but i think they were also showing signs of faster than normal discharge. As you probably know, high internal R also means faster discharge because the internal R drops more voltage and so the terminal voltage looks lower than it would be with lower internal R. So the cell becomes less useful anyway.


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## Climb14er (Jul 31, 2018)

All of my AA and AAA Eneloops are from 2006-7 and every two months, I run them all through a Refresh and Analyze Program with the MaHa C9000 and all of the Eneloops still perform very well.


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## WalkIntoTheLight (Jul 31, 2018)

MrAl said:


> Yes i think the CC17 would work, but i was using the CC55 which charges with higher current. Maybe i threw them out too soon, but i think they were also showing signs of faster than normal discharge. As you probably know, high internal R also means faster discharge because the internal R drops more voltage and so the terminal voltage looks lower than it would be with lower internal R. So the cell becomes less useful anyway.



You can always use them in low-drain stuff, like remote controls or low-output LEDs. As long as the self-discharge rate is slow, they work really well in low-drain devices, where higher IR doesn't matter.


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## RA40 (Jul 31, 2018)

Have 2 remaining of the 8 from our '06 Japan trip. Those two come in at 1,600-1,700. The 09's are ranging 1,700-just shy of 1,900. Would have been nice to had more of the 06 in use I recollect they came in "high" on the C9000 so they were recycled.

*edit* Found 2 more and cycled them, both came in at 184X.


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## MrAl (Aug 1, 2018)

WalkIntoTheLight said:


> You can always use them in low-drain stuff, like remote controls or low-output LEDs. As long as the self-discharge rate is slow, they work really well in low-drain devices, where higher IR doesn't matter.



Hi,

Yes i was going to say that but forgot 

Thanks for the update.
I guess i have enough Eneloop cells now that i dont have to worry about a few being discarded. It wasnt always like that, but i bought a couple packs of them so i have enough for my basic needs now. I use them every day in a few different applications like powered headphones and flashlights.
I dont have that many AAA size yet though.


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## WalkIntoTheLight (Aug 1, 2018)

MrAl said:


> I guess i have enough Eneloop cells now that i dont have to worry about a few being discarded. It wasnt always like that, but i bought a couple packs of them so i have enough for my basic needs now. I use them every day in a few different applications like powered headphones and flashlights.
> I dont have that many AAA size yet though.



My evidence is only anecdotal, but I find the AA have greater longevity than the AAA Eneloops. The AAA internal resistance seems to increase faster than AA, and will eventually prevent them from charging in some smart chargers.


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## MrAl (Aug 3, 2018)

WalkIntoTheLight said:


> My evidence is only anecdotal, but I find the AA have greater longevity than the AAA Eneloops. The AAA internal resistance seems to increase faster than AA, and will eventually prevent them from charging in some smart chargers.



Hi,

Very interesting. I knew they were lower capacity of course but didnt think about the other aspects yet.
I am now wondering how well they would work in a sort of high drain application like one of my newest flashlights that uses four AAA cells. I would really like to use rechargeable batteries in that.


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## WalkIntoTheLight (Aug 3, 2018)

MrAl said:


> Hi,
> 
> Very interesting. I knew they were lower capacity of course but didnt think about the other aspects yet.
> I am now wondering how well they would work in a sort of high drain application like one of my newest flashlights that uses four AAA cells. I would really like to use rechargeable batteries in that.



They'll handle 2-3 amps just fine. Very useful for modestly high-drain apps. In a 4xAAA light, they should be able to sustain 500 lumens quite easily, probably close to 1000 lumens at least for a little while.


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## jykelly (Aug 31, 2018)

Hi,

Newbie here. I bought some AAs in 2010 and AAAs in 2011. Still in regular use but they haven't been pushed much. AA got used in Guitar Hero peripherals originally so we're being recharged often but after that they've been mainly used in toys and my multimeter. AAAs are in remote controls and triple battery flashlights. Don't have a light meter but the AAAs still put out a decent amount of light in various XML T6 lights. Runtime is about 75% of what they did at the beginning.


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## magellan (Sep 6, 2018)

Great first post and welcome to CPF!


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## Kestrel (Sep 6, 2018)

I've got a 4-pack of new-in-package AAA's from 2006; in 2026 I will send them to someone for battery analysis.
Rest assured, we will post the info on CPF.


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