Best AA Rechargeable Batteries – The Eneloop – Why I Like Them

aa-rechargeable-battery

I consider the Panasonic ‘eneloop’ to be the best AA rechargeable batteries.

This update confirms that I still maintain this position after many years of use.

The eneloop battery chemistry is nickel metal hydride (NiMH or Ni-MH) rather than alkaline. A Low-Self-Discharge chemistry attributes to making it a great choice.

AA eneloop
(view on amzn)
eneloop rechargeable battery, AA size

Number of recharge cycles

The technology design of the eneloop will recharge up to 2,100 times! That’s another reason why (in my opinion) they are the best AA rechargeable batteries.

Factor in the cost of constantly replacing new batteries. The cost savings of these rechargeable batteries are excellent over time.

A more technical explanation about their superior number of recharge cycles:

Improvements to the conductive surface layer of the active (positive) electrode material (made primarily from nickel-metal hydride) produce greater conductivity and durability.

Limiting the degradation of the conductive layer increases the number of times that the eneloop battery can be recharged. ..up to 2100 times.

-from the manufacturer

No Memory Effect

The eneloop battery can be recharged when fully, or partially drained. It doesn’t matter.

Why? Because of its Ni-MH chemistry.

Charge with a Ni-MH type quick charger, smart chargers, plug in charger or universal chargers.

Long Storage Life (shelf life)

The eneloop is a ‘low self discharge’ (LSD) battery.

When fully charged, shelf life (holding a charge over time) is very long compared to older type rechargeable batteries.

A fully charged eneloop battery cell will maintain ~70% of their charge for up to 10 years (when not in use and stored properly).

High Capacity Battery Life

Capacity rating is an important thing to know when comparing batteries.

The capacity of AA (and other similar batteries) are rated / labeled as mAH, or milliamp hours. This represents how much energy the battery can hold.

This rating (capacity) is analogous to the gas tank in your car…how much fuel can be stored inside.

The higher the number, the more energy the battery can hold inside.

The standard Panasonic eneloop is rated for 2,000 mAh, 1,900mAh minimum. Yet another reason it’s one of the best AA rechargeable batteries.

Temperature Performance

All alkaline batteries perform poorly when they’re cold. However the eneloop performs pretty well in cold temperatures. Reportedly delivering good performance down to –4 degree Fahrenheit.

Tip: For even better cold weather performance, consider Lithium batteries. Though most consumer types are not rechargeable.

Battery Charger for the best AA rechargeable batteries

Be sure to use a ‘smart’ battery charger designed for Ni-MH batteries when charging the eneloop battery. Most modern battery chargers are ‘smart’ these days. But be sure to check.

This is the charger that I’ve been using for many years. I like it because it will recharge 8 batteries at once. It also charges ‘D’ size!

Maha Professional Charger for (8) AA/ AAA/ C/ D type
Maha PowerEx battery charger

If C-type or D-type batteries are not a concern, I recommend the following charger:

La Crosse Technology BC1000
(view on amzn)

[ Read: Solar Charger For AA or AAA batteries ]

Best AA Rechargeable Batteries – SUMMARY

The AA battery size is the most common consumer type used in portable radios, LED flashlights, and much more. The reasons that I believe this battery to be one of the best rechargeable batteries include the following:

1. High number of recharge cycles (2100)
2. No memory effect
3. Low self-discharge (long shelf life, 10 yrs.)
4. High capacity battery life (1,900 – 2,000 mAH)
5. Good low-temperature performance
6. My years of experience with the eneloop

Plus, it has the best overall reviews.

Note: In case you were wondering, they’re made in Japan.
Note: I have been using these for many years, and couldn’t be more pleased.

Panasonic (the ‘eneloop’ battery) has been an industry leader in Ni-MH battery technologies. They produces quality cells in consumer sizes (including the popular AA, AAA).

To save some money per battery, you can also purchase in bulk:

(24) AA eneloop
(view on amzn)

I really like this AA battery storage case. Years ago I bought a handful of them. Weather resistant, great to toss into a pack, camping, or whatever:

Rugged AA Battery Storage Case
Storage Case for 8 AA batteries

[ Read: Batteries That Will Not Leak Or Corrode ]

[ Read: Battery Corrosion, Why They Leak And How To Prevent It ]

Voltage Difference Between Alkaline and Ni-MH

Regarding the the battery voltage difference between alkaline and Ni-MH rechargeable batteries:

Alkaline batteries have a voltage of around 1.5 – 1.6v off the shelf. However they quickly drop to around 1.25v under actual load. They drop further over time to around 1v when almost discharged. This is due to their inherent ‘sloped discharge curve’.

Eneloop Voltage Discharge Curve

(source)

The rechargeable Ni-MH battery has a voltage of around 1.35v when fully charged. However under load they start around 1.2v but they continue to stay at 1.2v until the battery is almost fully depleted.

So under these typical conditions, there’s little or no effective difference between the two while under load (in my opinion).

Regarding electronic gear requiring 4 or more batteries in series, it is apparently rare to encounter a device which won’t operate or power on. Though always refer to the manual of any given product for recommendations.

Additionally most electronic gear design and manufacturers take into account the voltage characteristics of rechargeables.

That said, if the instructions say no rechargeable batteries, then it means the device will be slightly under-powered due to the device design.

…hope this helps.

 
This post has been updated with new information since it’s original publish date. Add your own comments and opinion below:

[ Read: Off-Grid Charging System For AA-AAA Batteries, USB ]

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39 Comments

  1. Eneloops really are great. I’ve had a stockpile of regular batteries for a while as part of my preps and as I use them now, I’m only replacing them with these. Much like you’re battery holder, I’ve been putting together “go packs” which consist of a cheap Amazon battery holder that holds AAA, AA, and a 9V. It’s also a good way for me to keep track of how many of each I have.

  2. I studied the whole rechargeable battery thing for a year b4 I also went with the eneloop. Bought some extra adapters for C and D usage. They are standing the test of time.

  3. I love eneloops. Eventually I’d like to get to the point where the only thing I use old school batteries for is the tv remote. I’m curious if there is a decent solar charger for AA that won’t get my wife’s hackles up when she sees the bill.

    1. @Nihilist, The following solar powered battery charger is a ‘basic’ and fairly low powered charger, but it will get the job done (eventually) in and emergency. It is not expensive, but I do have a few of them for ‘just in case’.

      Solar Power Battery Charger

      I also wrote the following article awhile ago while attempting to find a better solution to ‘smart’ charging consumer-size batteries with solar power. The components add up to be relatively expensive (but things are always ‘relative’….). I may take a new look at it and see if there are more economical solutions, but still powerful enough to be useful for ‘on the go’…

      Off Grid Charging System for AA AAA C D 9v

  4. Ken, thanks for this timely post.
    Just made two purchases, the eneloop batteries and the Maha PowerEx charger.
    Thank you for posting these items that are very valuable but were not even on my radar (though we have a supply of regular batteries).

    Thanks again Ken! :)

  5. Timely piece, Ken! I have my charger in the sun today, recharging a couple of AA batteries.

    I use a Crane 11-in-1 battery charger, that’s the one you refer to in your linked article above.

    I’ve been using Tenergy batteries and they work fine. However, their self-life when charged is a disappointment, as you wrote about.

    One of our purchases for this month is to buy a second Crane unit so I can charge 2 sets of batteries at the same time AND also have a backup, just in case.

    Was also planning to get some more rechargables and I planned to try the Eneloops to see how they perform. With the ‘memory effect’ now taken care of, this purchase is a no brainer. In the past, I’d always wait to switch out batteries only after a gadget goes belly-up.

    Gotta say how much better rechargables are than disposables!!

  6. I started with an 8-pack & charger. I was very impressed with the battery power, life, and charge holding capacity. Since that original purchase, I have bought another power pack with a variety of eneloop batteries (~20) including an additional charger. I primarily use them in my ICOM VHF radio, flash lights, and other electronic devices.

  7. Does anybody have any experience with using the eneloops in cold weather ?

    I know from experience that single use alkalines lose power VERY quickly, single use lithiums are far superior but much more expensive.

     
    [Ken adds: Lithium batteries are MUCH better in COLD weather. I always have a supply of those (driveway alarm transmitter, etc..) ]

    AA Lithium batteries

  8. Are 123A Lithium batteries rechargable and if so what type of charger is needed. Trekker Out.

    1. @Mountain Trekker,

      While I am currently using non-rechargeable ‘Surefire’ 123A batteries (I buy them by the dozen), evidently they do make rechargeable 123A batteries…

      Note: You need to be aware of the mAh (milliamp hour) rating of the battery (how much energy is able to be stored inside) because some are more or less than others. The Surefire batteries listed above are apparently 1500 mAh (non-rechargeable). Many of the rechargeable 123A batteries that I’m seeing are 750 mAh.

      Having looked at the many choices on Amazon, it seems that most of the 123A rechargeable batteries do not have very good overall reviews (not sure why that is).

      With that said, here’s some to look at,
      Rechargeable 123a Batteries

      1. Ken Thanks for the comeback. I also buy the 12 pack surefire non rechargable batteries. I checked out the site you showed and I’m suprised at how reasonable some of those chargable batteries with a charger really are. I have a Surefire flash light which I love, but it sure does eat the batteries. Thanks again. Trekker Out.

  9. I need to get a bunch of the different eneloop batteries, im tired of battery problems, have had good luck with energizers but are really expensive for something you throw away after a few weeks or months

  10. Ok so help me out here folks. I buy a bunch and charge them up and store them for 5yrs or so. They should be at least 70% charged then still right?

    [Ken adds: In theory, yes. Though what I do is this: I charge them every once in awhile, regardless.]

    Also how is the best temps to store them?

    [Ken adds: I’ve not had any issue at room temps., or higher temps in vehicle, etc..]

    How would they do sitting in my camper year round? It’s parked under a shade tree but is still hot/cold.

    [Ken adds: I have some in my camper year round. It even freezes during the winter. So far so good.]

    So would these be the best option to store in my AA battery packs for the Boefung Hams? They stay in my truck year round no matter the temps.

    [Ken adds: I keep two 2-way radios in my truck at all times (with eneloop batteries installed). Never had a problem.]

  11. Boys each received a set with charger and jackets for Christmas along with extra AA and AAA packs. I know the younger one will use. My oldest is an eye roller………. Oh well Momma’s money, Momma’s choice :-)

  12. i have been changing over to eneloop batteries for some time , on the recommendation from contributors on this blog ( any other sources ) and find the eneloop batteries have all the benefits listed by ken and others .

  13. Though the video is informative, there was (perhaps unintentional) negative bias towards the eneloop due to apparent misrepresentation of the the capacity numbers.

    The manufacturer says 1,900 minimum mAh.

    His test in the video compared his own results against 2,000 mAh. If comparing against manufacturer minimum numbers, his test result would have been 94% of its rated capacity.

    Additionally, apparently, the number of charge cycles of the eneloop is superior to others – even though some others may have a higher capacity rating.

    It’s nice though that we’re seeing some good rechargeable technology these days!

  14. I have been switching over to eneloop batteries for awhile now, they go into everything with a AAA or AA Batt.
    Sick and tired of buying a “regular” battery and tossing it out after awhile.
    I also have them (eneloops) stored in a fairly moderate temp place (around 60 deg) but have had zero problems with the 120 degree truck in summer.

    As far as long term storage, I just hit them with a recharge once a year, usually don’t take much, but ya never know when POOF goes the Dragon and we’re all on Solar for a decade or two.

    BTW, you do have a Solar Battery Charger….. Right????
    AND you have tested it to make sure it’s still working….. Right????

    1. NRP
      1) Does one have a solar charger?
      2) Did you have it tested?

      Depends on which type of solar charger you are referring to in your question. We have two but one is for a solar lantern which will also charge your cell phone and the other is a portable unit. Both are Goal Zero brands, and I doubt they will work on batteries for say the vehicles, or generator.

      My question to you is this. What would you recommend to keep a small battery for a generator trickled charged(solar)?
      I hate having to put them on a electrical plug in unit because I forgot to keep them at full power and there is no charge left in the unit, when a trickle solar charger will keep them going. There are days I am to swamped to remember all this stuff, my work card is busy.

      Last question can one leave the battery on a trickle SOLAR charger without any consequences to the battery(batteries)?

  15. I have been using Enveloop batteries , AAA &AA sizes for quite some time and am very pleased with the results . In normal times I use the wall charger unit . I did buy 2 C Crane solar chargers that I am also pleased with.

  16. Very interested in the contents of this article. Thanks, Ken.
    Sounds like a good investment.

    …..now I’m just waiting for my allowance to increase…..

  17. Has anyone used the solar re-charger? If so, I would like to know how well they work. We are getting ready to make the jump into these batteries, but I want to get a solar charger as a back-up.

  18. I encourage any solar newbie, buy a small kit system. Small panels, kind of a catch all charge controller with many options; cigarette lighter adapter, usb port, different sizes of pin adapters, various outputs, etc. It will allow you to play with your rechargeables and learn a little hands-on with times to charge with full sun etc.

    The only drawback that I can see, they are not portable. At least as far as, in a backpack or something. If you’re planning to bug-in, it would be the best choice.

    The fold-able panels are usually less powerful, but they could be displayed across the top of your backpack to allow charging as you walk. They are far more expensive as well. Lots of options for various scenarios.

    I’m gradually transitioning from Amazon brand rechargeables to eneloop. Both work, but the eneloop’s are better.

  19. Project Farm on YT has a comparison test on rechargeable batteries. I believe the brand that topped out on his tests was VARTA.
    A very good channel.

  20. Rechargeable batteries are great. Powerex makes rechargeable batteries that are just as good as eneloop only they make AA, AAA, C, D and 9 volt sizes. I bought mine at walmart online.

  21. Just wish eneloop had a C and a D battery, the capacity is so much more than using an adapter. I use tenergy lsd batteries in those sizes. So far they seem good but I do not have a long term (10 year) experience with them.

    1. I also use tenergy batteries for those sizes. They’ve been pretty good!

      Yes, adapters for these sizes make no sense whatsoever. The very purpose for having these sizes is to hold MORE ENERGY. So adapters are just a quick fix that’s not going to last very long.

      1. Hi Ken, I understand your Choice of Eneloop Batteries, but you Recommend the Maha Energy Charger, Have you tried the Maha Energy Batteries? Any thoughts on those?

        1. Maha Energy Batteries… I am dating myself… But now known as Powerex which is a Maha brand…

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