# eneloop vs Powerex?



## DirtyRat (Nov 16, 2011)

I've noticed there isn't even really a debate around here, there seems to be no questioning the Sanyo eneloop AA batteries. My question is, why? I understand everybody believes they're extremely reliable, but why doesn't Maha's Powerex 2700 AA battery which has 35% more juice than the eneloop 2000, get any attention around here? I'm not starting a arguement because I've never used an eneloop so I don't know their lasting power, but it just seems to figure that a battery with a larger capacity (an in my experience, a very reliable battery, just don't drop 'em, killed two from 6 ft. drops) would make more sense in flashlights.

I started on Powerex's off a very battery educated person's opinion about 12ish years ago. This kid was a genius and he didn't hesitate to suggest to me Maha Powerex for my digital camera, I've bought dozens and haven't been disappointed. 


Anyhow, again, not looking to start a GM vs Ford argument, or Honda vs Toyota if imports fit your fancy, but I'm just wondering why Powerex is rarely mentioned in these parts.


P.S. My 1st posts involved needing a flashlight recommendation, and I was lead toward the SC51, which I've been using for about a week now...LOVE IT. Will post much thanks later.


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## T-roc87 (Nov 16, 2011)

Its becuase the sanyo eneloop 2000 mah are a low self discharge battery which is great for those of us that dont use our lights on a nightly basis. They are able to hold like a 85% charge after a year of sitting. That would be why they are so well liked.


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## derfyled (Nov 16, 2011)

Regular NIMH like Powerex loose about 1% of their capacity per day when stored.


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## kreisler (Nov 16, 2011)

wrong forum section. in the battery forum section there's ..


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## treek13 (Nov 16, 2011)

Battery discussions can be found in the Flashlight Electronics - Batteries Included forum. 

If you search there, you will find many threads on eneloops like Noob question.. Why Eneloops?, Why Eneloops??, AA battery help needed, & How do the Maha/powerex batteries compare to eneloops.

Hope this helps.


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## DM51 (Nov 16, 2011)

kreisler said:


> wrong forum section.





treek13 said:


> Battery discussions can be found in the Flashlight Electronics - Batteries Included forum.
> 
> If you search there, you will find many threads on eneloops like Noob question.. Why Eneloops?, Why Eneloops??, AA battery help needed, & How do the Maha/powerex batteries compare to eneloops.
> 
> Hope this helps.


Correct. Moving the thread there.


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## The_bad_Frag (Nov 16, 2011)

You can buy Eneloop XX if you want more mAh. They have 2500 mAh and the same low self discharge rate as normal eneloops.


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## tbenedict (Nov 16, 2011)

I had a bunch of Powerex 2500's and 2700's due to the reviews from the camera sites. All of mine faded out to where they are only good in the Gerber IU's. I have not had one Eneloop go bad in the last several years..


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## RCM (Nov 16, 2011)

The highest capacity AA NiMH cells seem to die rather quickly, 2 of my Duracell 2650s (Sanyo 2700 mAh) now have incredibly high internal resistance, and will NOT charge anymore, they have been retired to my recycle bucket along with a REALLY crappy Chinese made 350 mAh NiCD that had it's polarity reversed AND leaked! I use duraloops a lot now...


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## samgab (Nov 16, 2011)

Incidentally, eneloops are Low SELF Discharge (as opposed to low discharge, which sounds like you can only discharge them at low rates).


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## RCM (Nov 16, 2011)

Alkalines should only be discharged at low rates, otherwise you risk reverse polarity! NiMH is better for higher current, but you should be sure they are matched, otherwise you risk polarity reversal with them as well, which causes damage to them! If it was me, I would go with the eneloop XX for lights that I use all the time, and regular eneloops for lights that don't get used that often. 
Just my 2 cents.


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## pinetree89 (Nov 16, 2011)

I bought a grundle of Powerex cells a number of years ago. They didn't last long, most would self discharge in a number of days. I've since gotten rid of all of them. They're pretty bottom of the barrel cells IMO. Eneloops are worth the price, they'll be there with a charge when you need them. I've also had good luck with Rayovac Platinums, but the edge goes to the Eneloops.


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## Battery Guy (Nov 16, 2011)

DirtyRat said:


> I've noticed there isn't even really a debate around here, there seems to be no questioning the Sanyo eneloop AA batteries.



First, you are comparing apples and oranges. The Powerex 2700 cells are not LSD (low self discharge) NiMH cells. I consider these to be almost a different cell chemistry as their usage and maintenance attributes are quite different.

Second, please take a look at the extensive testing that has been done comparing various AA NiMH cells to Eneloops found in the AA NiMH Performance Test Thread. You will see that a lot of work has been done to compare various cells to Eneloops.

I have not tested the Powerex 2700 AA, but I have tested the Powerex Imedion 2400 AA, keeping in mind that the 2700 is not LSD and the 2400 is LSD. The Imedion 2400 cell does have higher capacity than the 2000 mAh Eneloop, but it has a much higher internal resistance.

For raw performance in an LSD NiMH AA, you simply cannot beat the conventional Eneloop and the Eneloop XX (aka Eneloop Pro). The new Elite 2000 cells beat the Eneloop on power capability, but they do not have the LSD properties of an Eneloop.

Paraphrasing Mr. Happy from a post long ago: "There are two types of LSD NiMH cells, Eneloops and non-Eneloops." My testing seems to confirm this. Sanyo simply has the edge when it comes to this type of cell. Specifically, they have low internal resistance, fantastic capacity retention, excellent calendar life and outstanding cycle life. I don't think that any other LSD NiMH cell is equivalent on any of these performance metrics.

That being said, Eneloops and Eneloop XX cells are pricey, and you can find other NiMH cells that give you more from an initial $/Ah metric. However, no NiMH cell has the track record of the Eneloop.

Cheers,
BG


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## bbb74 (Nov 16, 2011)

T-roc87 said:


> Its becuase the sanyo eneloop 2000 mah are a low self discharge battery which is great for those of us that dont use our lights on a nightly basis. They are able to hold like a 85% charge after 3 years of sitting. That would be why they are so well liked.



I do think that if you have cells that sit around doing nothing for 3 years, given the cost, lithiums would be a better choice than eneloops.



Battery Guy said:


> First, you are comparing apples and oranges. The Powerex 2700 cells are not LSD (low self discharge) NiMH cells. I consider these to be almost a different cell chemistry as their usage and maintenance attributes are quite different.



I have done some comparisons which include power 2700, imedion 2400, eneloops and vapex instant 2400's here: http://www.candlepowerforums.com/vb/showthread.php?317990-AA-NiMh-Shootout!!

From this testing (and from my experience) the powerex 2700's are close to LSD in self discharge, but they lose capacity much faster than the others with the number of cycles of use. Unless capacity was the *only* thing that concerned you, you'd be better off looking at the imedions or vapex (I'm only listing brands I tested). For the lowest capacity but probably most amount of toughness, go the eneloops.

I've got imedion 2400's that have been smashed around on the front of my bicycle for over a year now. After ~90 cycles they've lost about 2% of their original capacity which is excellent in my book. I don't have eneloops getting the same treatment to report on. The powerex getting similar treatment (but fewer cycles!) are down well over 10%.


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## Wrend (Nov 17, 2011)

One of the distinguishing characteristics I've added to my list of things to check to determine the quality of a cell is its expected cumulative lifetime capacity.

In this, standard "1500" cycle Eneloops even beat the XX Eneloops by 2.4x, which seems the better value to me than the 1.25x capacity per charge.


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## snakyjake (Nov 17, 2011)

I've presumed that if I plan to deplete my battery within a month, I'd be better off with high capacity non-LSD. The PowerEx 2700 has 35% more capacity than LSD 2000. With a decay rate of 1% per day, it should take more than 35 days to break even with a 2000 LSD. But now some are mentioning cycles, so I don't know anymore.


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## Mr Happy (Nov 17, 2011)

The 2700 cells are good when they are new, but they don't stay new and you may expect some cells in a group or pack to get out of balance, to develop high self-discharge, or to go high resistance after a possibly short time of ownership. Additionally they have a higher internal resistance so will develop a lower voltage under load than some other cells.

You are making a trade-off between cost and ultimate capacity. If you are prepared to buy new cells and replace them often in the pursuit of maximum capacity then the 2700's may be for you. If you are looking for economy, assurance and general lack of fuss, then eneloops would be the better choice.


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## Groundhog (Nov 18, 2011)

I use both the Powerex 2700's and the Eneloops.

I use the Powerex in my bike light and my EDC light because I generally use a 4pk within a week of charging them and I think there is a little longer life in that battery. In my remotes it is definitely Eneloops. They don't lose their charge after a few months so I am changing batteries a lot less often. For a digital camera that you are using frequently the Powerex is a fine choice if you have a freshly charged battery. If it might sit for a couple months before use I'd go with an Eneloop. 

With LSD batteries up to 2500 mAh the Powerex 2700's are almost outdated technology. A dozen years ago when your friend recommended the Powerex he was giving you a great tip on a battery. There's a good chance he is using Eneloops today in many devices.

I'd give the regular Eneloops a try next time you buy. Keeping 85% of their charge after 3 years in a drawer is kinda handy. They may not become your preferred digital camera battery but I'm sure you will be pleased with their performance in remotes and such.


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## DirtyRat (Nov 22, 2011)

Thanks for all the responses. Great read, very informative, as well as the links to other topics about this. I didn't realize there was this forum about batteries. I normally hop straight to the LED forum. For my use, I burn through a AA a week, normally 4 days it seems. I use my SC51 very often at work, so to me it seems to make sense to use the higher capacity jobs, as self discharge over an extended period is not a concern for me. 

Incidentally I am using the 2400 LSD Imidion in my Zebralight, and somebody commented that the Imidion is higher internal resistance than enellops, I wonder if this is why I notice little difference between this highest high setting, and the lowest. I think the lowest is around 100 lumen, and the highest is 200, well it's definitely not twice as bright. I'd wager 50% brighter, but not twice as bright. Based on the thoughts I put some eneloops on my Christmas list! Sadly the XX ones don't seem to fit the bill price wise, simply too expensive.


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## Mr Happy (Nov 22, 2011)

DirtyRat said:


> I think the lowest is around 100 lumen, and the highest is 200, well it's definitely not twice as bright. I'd wager 50% brighter, but not twice as bright.


That seems about normal. 200 lumens doesn't look twice as bright as 100 lumens because our eyes don't perceive brightness in that way. The only way to really tell is to use a light meter.


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## tbenedict (Nov 22, 2011)

If the SC51 doesn't seem as bright as normal, clean the contacts and make sure the tail is snug. You wouldn't think this would affect the brightness much, but it does on these.


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## bbb74 (Nov 22, 2011)

DirtyRat said:


> Incidentally I am using the 2400 LSD Imidion in my Zebralight, and somebody commented that the Imidion is higher internal resistance than enellops, I wonder if this is why I notice little difference between this highest high setting, and the lowest. I think the lowest is around 100 lumen, and the highest is 200, well it's definitely not twice as bright. I'd wager 50% brighter, but not twice as bright.



Mine is the same - little difference between H1 and H2 - small enough that sometimes I can't even tell any difference. I should try it with an eneloop and see if that makes a diff.


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## cad3 (Dec 13, 2011)

Wrend said:


> One of the distinguishing characteristics I've added to my list of things to check to determine the quality of a cell is its expected cumulative lifetime capacity.
> 
> In this, standard "1500" cycle Eneloops even beat the XX Eneloops by 2.4x, which seems the better value to me than the 1.25x capacity per charge.



So you think it's better to have 3 sets of the "1500" cycle vs. 2 sets of XX Eneloops for a camera flash? Value for money, longevity, price, etc. I know there are a LOT of factors and 3 sets give (nominally (2000x3) 6000 vs. (2500x2) 5000. But then you have extra weight, etc. On the other hand, you have recycle time of the flash.

I'm looking at what rechargeable to use with my Canon 580 EX II camera flash, and back-up flash (580 EX). Thanks for any input you provide!


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## Wrend (Dec 14, 2011)

> So you think it's better to have 3 sets of the "1500" cycle vs. 2 sets of XX Eneloops for a camera flash?



Yes, I do. I even think it's better (in a way) to have 1 set of the "1500" cells than 2 sets of the XX cells.

The determining factor of what you need is how long you need the cells to run for on one charge. But as far as that goes, I think it's better to have extra charged sets ready to use than cells that only offer a marginally longer run time and cost twice as much. I don't really consider weight to be much of a real issue unless you're carrying around 100s of cells, of course.


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## pweber (Dec 15, 2011)

Hmm, I just bought 8 Imedion C cells and now I'm starting to worry that I'd wasted money. Aren't Imedion the same as Powerex? Anyone have any experience with the larger C-cells? I think mine are 5000mAh.


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## bbb74 (Dec 15, 2011)

pweber said:


> Hmm, I just bought 8 Imedion C cells and now I'm starting to worry that I'd wasted money. Aren't Imedion the same as Powerex? Anyone have any experience with the larger C-cells? I think mine are 5000mAh.



Imedions are made by Maha, which also makes Powerex.

I haven't used Imedion C size, but have got AA and AAA Imedions and they have been excellent. Higher capacity than eneloops and have been very tough so far. They're still doing really well after about 100 cycles, although eneloops would probably do very slightly better at this point with less variability. I wouldn't say you have wasted your money.


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## CyberCT (Dec 16, 2011)

My vote would be to go with the Imedion 2400 MAH AA cells. On Amazon, if you buy a 16 pack, the are roughly equivelat dollar for dollar to the eneloop AAs.

After testing my eneloops and Imedions in both my high powered Fenix lights (TK41, TK45) and charger that reads overall MAH (Maha C9000), the Imedions last about 14% longer than eneloops on turbo mode in all my tests. The Imedions average something like 2320 MAH though, not 2400 MAH as advertised. My eneloops average around 1990 MAH. From extensive tests done by other users as mentioned above (including LSD tests), the Imedions are great batteries and with the dollar cost roughly the same and I can't recommend eneloops over them. 

I have 8 Imedions (just bought the 16 pack, in the mail) and I have 32 eneloops.


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## Groundhog (Dec 16, 2011)

pweber said:


> Hmm, I just bought 8 Imedion C cells and now I'm starting to worry that I'd wasted money. Aren't Imedion the same as Powerex? Anyone have any experience with the larger C-cells? I think mine are 5000mAh.



It's slim pickings for quality NiMH C or D cells. Bought a few of each the Imedion (Low Self Discharge)and the Powerex (not LSD) in both sizes and they perform fine for me. Also bought 9V Imedions. I don't do all the extravagant testing others do so I can't really attest to their quality versus another brand or quote mAh stats. They might not be the absolute best performer or the best for the buck but I think there is a level of trust there that few can match.

The Maha AA and AAA are made in Japan and the C, D & 9V cells are made in Taiwan. For AA and AAA being made in Japan is generally good and being made in China or Taiwan is not. Not sure how the C, D and 9V production varies from the AA and AAA sizes. Doesn't surprise me they are not 'up to snuff' compared to the AA and AAA just based on where they are made.

They probably aren't worth the cost but your options are limited. Tenergy might be the best 'bang for the buck'. AccuEvolution brand has apparently tailed off in quality. The Maha's are about as good as anything just more expensive.


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## ICUDoc (Dec 17, 2011)

FWIW I use the Imedion 2400s and Eneloops. I don't tend to use them in ultra-high-drain devices but I find the Imedions DO have the higher capacity as claimed and tested on these forums. The Eneloops are excellent at keeping their capacity over time, so I am happy with both. The MAIN problem with both these cells is that their packaging (i.e. outer battery cover) falls apart or gets torn far too easily. So WELL short of their 500+ cycle life they become dangerous as their conductive metal shell becomes exposed after 30 or 50 uses. They are still great value for money, IMHO.


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