Review: Eneloop Batteries

By Betsy Finn, CPP

Sanyo’s Eneloop batteries are a new twist on the traditional rechargeable battery; they can retain 85 percent of their capacity over a year’s time. Because of this unique characteristic, Sanyo is able to package Eneloop batteries so they’re ready to use when you need them. The question is: Does this convenience factor come at a cost in performance? Can professional photographers really rely on a battery that is only rated at 2,000 mAH (compared to the more typical 2650 mAh or 2900 mAh)?

I was curious to see how Eneloop batteries compared to standard Ni-MH rechargeable batteries. To compare their performance, I used three Nikon Speedlights with four batteries each, set on manual flash power (one as the on-camera master, the other two as remotes). One of the remote Speedlights would be powered by Eneloop batteries, the other by standard Ni-MH batteries. After doing some research online, I discovered that my Nikon SB-800 Speedlights, at full manual power, should have a recycle time of four seconds when using Ni-MH batteries, and allow for 150 shots to be fired (Source: With that in mind as a guideline, I set out to test the 150-shot theory and see how the Eneloop batteries compared to the standard Ni-MH batteries.


Image ©Betsy Finn

Interestingly, the Eneloop batteries actually outperformed the standard batteries until the 137th flash. Both sets of batteries then recycled within milliseconds of each other through the 200th flash. After that, the capacity of both batteries began to degrade rather quickly. At the 212th flash, the Eneloop batteries finally fell behind the standard Ni-MH batteries in recycle time, but at this point, neither Speedlight had enough capacity left to practically fire the flash (21+ seconds to recycle). After the 213th flash, the Eneloop batteries could not fire the unit at all. Over the first 150 flashes, average Eneloop recycle time was 4.65 seconds (compare to the standard Ni-MH of 5.03 seconds).

What’s my verdict? While there is certainly a trade-off between convenience and performance, using Eneloop batteries will be a viable option for some photographers. I can see using Eneloop batteries in place of standard Ni-MH batteries if you are comfortable with recycle times of around 4.65 seconds (fewer, if you add the fifth battery accessory or use an AA-powered battery pack).

A four-pack of Eneloop batteries retails for $14.92, and can be found through various retailers including For a more detailed analysis of my test runs, including data and graphs, see "Are Eneloop Batteries Too Good to be True? Nope!"


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Comments (16)

I used AA Eneloop batteries with my INON underwater flash system on a recent assignment in Australia. INON and several flash manufacturers are recommending Eneloop batteries because they don’t heat up as much during discharge. This is more important consideration underwater since the flash units usually fire full out on every burst, but it might be a "hot" feature for land-based power users. They lasted for several hundred shots on each dive, but took much longer to charge than my 2650 Ni-MH Duracells (using a rapid charger-not recommended for Eneloop.)

I've been using Eneloops this entire year for wedding photography. I use them to fire my master and slave Canon 580ex flashes, with the additional Canon AA battery packs. I have no complaints, they seem to work just as well now as when I first bought them!

I am confused. The Eneloops are 2000mAh and you mention the "more typical" ratings for Ni-MH as 2650 or 2900mAh but you don't come right out and say what the rating was of the actual Ni-MH batteries you tested against the Eneloops.

The reason why I ask is that your "verdict" seems confusing to me.

On the one hand, you mention that the Eneloops recycled FASTER than the Ni-MH batteries through 137 flashes and then equalled them right up until the 212th flash. That sounds like a POSITIVE thing to me.

And yet, to contradict your glowing report, you then summarize with a verdict that states: "While there is certainly a trade-off between convenience and performance, using Eneloop batteries will be a viable option for some photographers. I can see using Eneloop batteries in place of standard Ni-MH batteries if you are comfortable with recycle times of around 4.65 seconds".

The first sentence is hesitant (merely "viable" given trade-offs?) and the 2nd sentence alludes to 4.65 second recycle times as almost a "bad" thing when your glowing review above seemed to state that the Eneloop was recycling faster than Ni-MH batteries.

So which is it? Are they better or are they worse than Ni-MH?

OR ... what I'm really guessing here is, did you decide to test the 2000mAh Eneloops against some very old 2000mAh Ni-MH batteries thinking that would somehow be fair? If so, you should have included that information in your review and then also test again today's common 2900mAh batteries and report on how those compare.


One thing to consider in the debate between "standard" Ni-MH batteries and the Eleloops is that most standard Ni-MH batteries can be "quick charged" in 30-60 minutes. With the Eleloops, Sanyo recommends using their special charger that will take between 4-6 hours to charge. It's one of those things I wish I had known before I invested in a few sets of Eneloops.

James Hafner. Not sure if you work as a photographer on a regular basis and you read most suggested information regarding rechargeable is usually recommended to NOT use quick chargers on many rechargeable batteries because they are said to degrade the battery over time. So there is no advantage to quick charging other than getting you out shooting faster for an impromptu shoot. Most of the working photographers I know of prepare the night before by charging their batteries.

You also might want to have those standard batteries handed just in case you actually do need to do a quick charge.

Quick charge is at a price. It's like the saying goes 'do you want it fast or do you want it right?'

I have to disagree with Cordell's insinuations, and merits of quick chargers. I don't have time to wait 4 hours to charge 4 batteries. I'll run 3 sb800's with a fifth battery, and a mbd10 grip with double A's. On average, I'm recharging 18-23 double A's a night with my quick charger.

Honestly, I'm not concerned about nimh battery longevity. Getting to sleep at a reasonable hour when I'm shooting back to back days is much more important. With that said, my nimh's last 1-2 years (a minor expense for a good night of sleep).

Regarding the eneloop review, it's worthless without knowing the exact nimh batteries (and their age/usage) they were compared to.

I just saw the link at the bottom of the story. So we know Betsy used 2650 nimh batteries, and that's all. Which brand, how old were they, how many recharges did they have, what kind of recharger was used, or were they new?

The first test was done on partially charged eneloops. How is partial quantifiable, and who in their right mind would take only partially charged batteries out into the field?

I got a little excited about this when I saw the headline, but the testing is full of holes.

"insinuations" are far from what I am stating here.

What *I* read over the years and on various sites is pretty much the same; I'm not one to believe everything he reads either. Obviously your own experiences may be different.

On the other hand if someone sits there and watch the charger charge batteries I have a few more questions about their time. I plug mine in and go to bed.

I also own a couple of quick chargers for when I need them. No biggy AND I'm prepared.

Paul Grupp:

I think the point some are missing is that Eneloops hold their charge for months. So quick charging is less of an issue. All my life I've been recharging batteries just before a shoot to ensure that they were fully charged. With Eneloops, I charge them as soon as I get back from a shoot. It doesn't matter if the shoot is the next morning, or a few weeks out -- they hold their charge.

Don't have time to wait 6 hours for a recharge? Then just buy a few extra sets so you always have plenty in reserve -- again, this works now because Eneloops hold their charge far better than standard NiMHs.

To clarify the "standard" batteries referenced in my review....

As already discovered, I used 2560 mAh rechargable batteries (I thought I had stated that in the review, my apologies).

For the purposes of fairness in my test, I used a brand new set of Duracell 2560 mAh batteries, that had been fully charged one time prior to the test.

So,base on my experiment, the eneloop batteries (2000 mAh) actually outperformed the brand new, freshly charged 2650 mAh batteries (Duracell).

Some photographers prefer a shorter recycle time... so while the eneloops did more than hold their ground against the 2650 mAh batteries, I did not specifically test them in comparison to 2900 mAh batteries.

In regards to the test done on the partially charged batteries. That was to simulate the long-term storage... to see whether a photographer could rely on an "off the shelf" package of eneloop batteries in a pinch.

Prior to my main test (where I fired the ~200 flashes) -- both sets of batteries were fully charged. In fact, the "standard" 2650 mAh batteries had just been charged for the first time, and the eneloop batteries had been charged for the first time as well (they leave the manufacturing plant with ~75% capacity from my understanding).

As far as my testing being full of holes, I would love to hear your opinion on what I could have done better. I would have liked to do in-depth testing on multiple brands of batteries (i.e., compare 2650 mAh as well as 2900 mAh), but that wasn't the focus of this article. This review was not an in-depth comparison of multiple battery types. It was really to see if the eneloop batteries held up to the hype of maintaining their capacity over an extended period of time... as well as to discover whether they could be feasibly used in place of standard rechargeable batteries.

Eneloop batteries are great to have for many different reasons. They're inexpensive enough you can keep Eneloop batteries around and still keep so higher mha rechargeable when you may need the faster recycle time.

Great write up!:D

Thanks for doing the study, I've wondered about performance (I've been using them for over a year) and your article just confirmed my hunch that they recycled faster. Weird since they are in a sense less powerful.

The thing that really sold me though was that I never wonder about my batteries in my camera bag. I have 3 sets of E's and 1 set of old fashioned (though same age) AA's. I never really know with the regular ones, so I have to charge them before weddings.
My gripes:

"certainly a trade-off between convenience and performance"???

For the majority of the shots the Eneloop's did better. And they are way more convenient- so how is that a "TRADE OFF"???

Sounds to me like they are better on both ends of convenience and performance. Why just "viable option" and not a more honest "better option"?

Ahhh. I see what you are saying. Let me clarify my thoughts (i.e., where I was going with the "trade-off" comment).

"For the majority of the shots the Eneloop's did better. And they are way more convenient- so how is that a 'TRADE OFF'???"

This phrase would have been clearer: "certainly could be a trade-off between convenience and performance"... IF you are using 2900 mAh rechargeable batteries (as I only tested how the eneloop batteries compared to the performance of the 2650 mAh rechargeable batteries).

Does that make more sense? :)


Technical testing at

I'm surprised that no one has mentioned the Duracell Pre-Charged NiMH batteries, which appear to have similar properties to Eneloop, including the same 2000mAh capacity (and a similar PREMIUM price tag). According to the Duracell FAQ:

"It is not necessary to charge Duracell ActiveCharge (the name used in UK) NiMH cells before use because they retain up to 75% of their capacity after one year in storage. However, it is necessary to charge Duracell Base NiMH cells before their initial use as they lose 1% to 2% of their capacity per day while in storage."

Also, according to Duracell, these batteries can be charged in any Duracell charger, including the 15-min charger. Perhaps the test that started this conversation should have been between Eneloop and Duracell Pre-charge batteries to see if there's any difference at all between them, or if the Duracells actually charge quickly its fast charger.
Interesting photo link:


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