Best AA Batteries That You Never Heard Of

Just about everyone uses AA batteries. But few people use the best AA batteries, or have even heard of them.

What are these batteries? Why are they so great? Where can you buy them? What charger do you need to buy?

It’s Eneloop. Low self-discharge, 1500 recharges.

That’s the short answer. Here’s the long answer:

What are Eneloop Batteries?

Update: The explanations in this section remain accurate. However, some products discussed in later sections have been updated or discontinued. For latest updated product information, see 2018 AA Batteries update.

Eneloop batteries are a low self-discharge version of NiMH AA rechargeable batteries. Low self-discharge rechargeable batteries lose energy very slowly when sitting idle. This type of battery was pioneered by Sanyo in 2005 but has since been copied by many other brands.

Eneloops are difficult to market because the benefits cannot be clearly communicated in one or two short phrases. The packaging for these batteries typically communicates that they are “pre-charged” in large letters. The fact that they are low self-discharge is mentioned in the fine print. Few people know what low self-discharge means, and even fewer will learn by reading a technically detailed article.

In layman’s terms, here’s why low self-discharge batteries like Eneloop are so much better than Alkaline or high self-discharge NiMH batteries:

Why the Best AA Batteries are Eneloop Low Self-Discharge NiMH Rechargeables

Batteries store energy. Batteries “discharge” their stored energy to provide power to gadgets. Batteries also “self-discharge” their energy when not in use. An unused battery will eventually self-discharge so much energy that it will no longer be able to provide any power.

Devices use energy, often from batteries. “High drain” devices like digital cameras drain batteries quickly. “Low drain” devices like remote controls drain batteries slowly.

Alkaline AA batteries are very popular. They’re cheap. They perform well in low-drain devices. Voltage starts higher than NiMH batteries at 1.5 V (certain devices require this). Most important is their low self-discharge rate. You can buy an inexpensive bulk pack with dozens of AA Alkaline batteries. Idle Alkaline batteries will still work 3-5 years after purchase, or even longer if stored in cool, dry conditions. But two properties of Alkaline batteries motivate people to seek alternatives:

  1. They are single use. When depleted, you’ll have to spend time and money to buy more. You’ll also send many batteries each year to a landfill or hazardous waste facility.
  2. Alkaline batteries perform poorly in high drain devices such as digital cameras.

Before Eneloop came along, high self-discharge rechargeable NiMH (Nickel Metal-Hydride) AA batteries were the preferred option for high drain devices. They perform better than Alkaline in digital cameras. They can be recharged hundreds of times. Instead of buying a few dozen Alkaline batteries per year to power your digital camera, you can rotate two sets of rechargeable batteries between the camera and the charger every few weeks.

High self-discharge NiMH batteries can be inconvenient to use, because:

  1. The self-discharge rate is too high. For 2400 mAh batteries, 20% to 30% of stored energy discharges in just the first month. Higher capacity batteries discharge even faster. The stored energy discharges completely in just a few months.
  2. Managing rechargeable batteries is a chore. A typical family with children may have 15-30 devices that have 30-60 AA or AAA batteries. Rotating batteries out of 15-30 devices every 3 months is time consuming, to say the least.

Enter Eneloop. These batteries are suitable for all devices. Like Alkaline batteries, they self-discharge at a low rate. They perform as well in high drain devices as high self-discharge NiMH batteries. So these batteries are well suited for both remote controls and digital cameras. But that’s not all. The original Eneloop batteries can be recharged 1000 times. They last 83 years if recharged once/month. The newer Eneloops recharge 1500 times, or 125 years if charged once/month.

And let’s not forget the very best benefit. Need batteries right away? Put ‘em in. Like Alkaline batteries, idle Enloops retain most of their charge for years: 85% after 1 year, and 75% after 2 years. So it hardly matters if your Eneloops haven’t been charged for months. They’re ready to go. That makes them more convenient to use than high self-discharge batteries.

Eneloops cost a little more than high self-discharge NiMH batteries and much more than Alkaline batteries. But they perform better and can be recharged 1000 times. So buying Eneloops results in lower costs and energy use over the long run, less time recharging, fewer trips to the store, and a smaller number of batteries going to the land fill.

But Isn’t 2000mAh Low?

Wait a minute, you say. Eneloop batteries have just 2000mAh, while other NiMH batteries have 2600mAh or more. Less mAh (milliampere-hours) means less stored energy right? Yes. But only when fully charged.

Five weeks after you take both types of batteries out of a charger, they will all have around 1900-1950 mAh remaining. Five months after you take both sets of batteries out of a charger, Eneloops will have 1850-1900 mAh remaining while high self-discharge batteries will be close to dead. This leads to the following practical advice for digital cameras or other high drain devices:

If you use a digital camera to take flash pictures just a few times per week, you’re much better off using low self-discharge batteries such as Eneloops. They’ll last longer thanks to lower self-discharge rates. A spare set of Eneloops kept with the camera will be useful even if they haven’t been charged in a while.

If you use a digital camera to take hundreds of flash pictures per week, you’re better off using high self-discharge NiMH rechargeable batteries rated for 2600mAh or higher. Just make sure that the 2600mAh batteries you insert into your camera are fresh out of the charger.

Best AA Batteries to Buy

I recommend Eneloop over competing brands. They were first. They continue to improve. They make accurate claims. You know what you’re getting when you buy an Eneloop: low self-discharge, high quality NiMH batteries.

Some competing brands are a little cheaper, some offer slightly higher capacity, and some offer other minor advantages. But the marketing claims for these subtle benefits are sometimes misleading and often confusing. Some brands use nearly identical packaging for both the low discharge and high discharge batteries. And just because a brand claims a higher mAh rating doesn’t necessarily mean it’s better than Eneloop, as this battery comparison demonstrates. Given the low cost of batteries, and Eneloop’s great track record, I’m not willing to spend the time and effort to find a slightly better battery than Eneloop.

All Eneloop batteries are low self-discharge. All come pre-charged between 60% to 80% full. But there are now three different kinds, which I will call the “old,” the “1500” and the “XX.”

I prefer the new Eneloop 1500 since these batteries became available in late 2010, but I describe here the differences between the 3 versions so you can make the best choice for you:

Old Eneloop: The old Eneloops are very similar to the newer 1500s, and for many practical purposes are the same. Both are rated for 2000mAh. The discharge rate is only slightly worse. And not too many people are going to care if once/month recharges will last for 83 years or 125 years (1000 versus 1500 recharges).

One thing caught me off guard with my first purchase of the old Eneloops. When you first charge them, they only reach 92% to 98% of their advertised 2000 mAh capacity. Each battery must go through 3-5 cycles of full discharge followed by full recharge in order to reach or exceed the stated capacity of 2000mAh.

To reach maximum capacity, you’ll need to “condition” (also called “refresh”) each Eneloop battery. Conditioning means to discharge and recharge repeatedly until a battery reaches full capacity. Repeatedly “testing” a battery can accomplish the same thing, but requires more steps.

Though old Eneloops typically sell for 5% to 20% less than the 1500 Eneloops on Amazon, I don’t recommend them anymore because for the minor price difference you may as well get the 1500 Eneloops which are better in several minor ways.

1500 Eneloop: The new 1500 Eneloops are similar to the old Eneloops in both appearance and performance. Packages containing the new Eneloops have “Recharge up to 1500 times” printed on the package. Sanyo claims several subtle advantages for the 1500s over the old Eneloops. These advantages are:

  • slightly lower self-discharge rate (85% remaining after year 1, 80% after year 2, 75% after year 3, as compared with 75% remaining after 2 years for the old)
  • they can operate at lower temperatures (-20 C vs. -10 C)
  • they can recharge more times (1500 vs. 1000)

In my view, the biggest advantage is not even advertised: The first time you charge a 1500 Eneloop, it will almost reach the rated capacity of 2000mAh. After just two rounds of discharge/recharge, it will reach maximum capacity. I’ve also found that maximum capacity of the 1500 Eneloops is higher than the old Eneloops by 1% to 3%.

Furthermore, 1500 Eneloop batteries now state “minimum 1900 mAh.” In my tests, this proved to be true after one round of discharge/recharge for all 8 batteries (low of 1933mAh). All were at least 2030 mAh after the second round of discharge/recharge. Subsequent discharge/recharge cycles did not increase capacity.

The 1500 Eneloops typically cost 10% to 20% more than old Eneloops. In my opinion, the extra convenience is worth the slightly higher cost. List price is $26.99 for 8, but 8-packs can sometimes be had for less than $22:

Eneloop 8 Pack AA NiMH Rechargeable Batteries

XX Eneloop (Later renamed to Eneloop Pro): The 2500mAh XX rated capacity is 20% higher than other Eneloops and most of the competition. However, they cost over twice as much as regular Eneloops. Also note that they can be recharged 500 times and will retain 75% of the charge after 1 year. If you value your time far more than your money, these are the batteries for you:

XX Eneloop Pro 4 Pack AA NiMH Rechargable Batteries

Best AAA Batteries to Buy

Everything I’ve discussed about AA batteries applies to AAA batteries, though the smaller size means smaller capacity. Some Eneloop battery bundles include AA and AAA batteries in one package at a modest discount to buying AA and AAA batteries separately.

Which Charger to Buy?

All NiMH batteries need to be charged with “smart chargers” which won’t overcharge. Unfortunately, charger quality is all over the map, and most cheap chargers should be avoided.

Sanyo only guarantees their batteries if you buy an Eneloop or Sanyo branded charger. The least expensive way to get an Eneloop charger is to buy it as part of a battery bundle.

According to avid Amazon battery charger reviewer NLee the Engineer, the Sanyo Eneloop MC-MQN06U NiMH 4-Battery Charger included with most Eneloop bundles is mediocre and should be avoided. The critical missing feature from this and many other lower quality chargers is the ability to charge each battery independently (as opposed to requiring pairs).

However, the following 2-battery USB Eneloop charger which includes 2 AA Eneloop batteries is a great combination of acceptable quality, great portability, and low cost (discontinued, remaining units are expensive):

Sanyo MDU01S USB 2-Battery Charger with 2 New 1500 Eneloop Batteries

If you want a four battery charger, you have a few choices, depending on how fancy you want to get.

The simplest and lowest cost charger with minimally acceptable quality is the Sony Cycle Energy BCG34HLD4KN Power Charger with 4 Pre-Charged 2000 mAh AA Batteries. The included batteries are low self-discharge NiMH batteries similar to Eneloop.

If you want to use your batteries at maximum capacity, you need to condition them with a “refresh” or some other means of repeated discharge/recharge. The above two chargers don’t do that.

The following 4 chargers have a “refresh” function. The refresh function on the first charger listed below does a single discharge followed by a single recharge. The refresh function on the 3 La Crosse chargers which follow will repeat the discharge/recharge cycle until batteries reach maximum capacity.

This Sony charger, which costs a little more than the above Sony charger, offers a refresh function, faster charging, and individual cell indicators:

Sony Cycle Energy BCG34HRE4KN Refresh Charger and 4 Pre-Charged 2000 mAh AA Batteries

The BC500 is a step up in features, including battery testing. With testing you can determine maximum capacity and identify bad batteries. The BC500 is also very portable and can charge batteries in a car using the included adapter. The BC500 sacrifices ease-of-use and has a smaller display size compared to larger models. It is best suited as a travel charger:

La Crosse Technology BC500 Alpha Power Battery Charger

For additional control, easily accessible features, and a large display, the terrific La Crosse BC700 charger typically costs less than $40:

La Crosse Technology BC-700 Alpha Power Battery Charger

I personally use a La Crosse BC900 Charger which has a higher maximum charging rate than the BC700. Unfortunately, it was replaced by the new BC9009 which I cannot recommend due to overheating issues.

The new La Crosse BC1000 Charger is very similar to the BC-900 and BC9009 as all 3 offer a higher maximum charging rate than the BC700 and have seemingly identical features. However, the BC1000 has internal changes that may address the overheating issue. La Crosse’s web page for the BC1000 includes the language, “Overheat protection to protect battery life. If any one battery or circuit over heat, the charger will stop all channels charging and discharging.” The web page for the BC9009 does not include this language. The BC1000 is more expensive than the BC700, so only purchase this more expensive unit if being able to very rapidly recharge batteries (2 AA batteries at 1800mA, or 4 AAs at 1000mA) is important to you:

La Crosse Technology BC1000 Alpha Power Battery Charger

You can spend even more money on a Maha PowerEx charger for a little more flexibility, a little more control and an even faster charging rate. But the Maha is harder to use. For most people, the easy-to-use La Crosse BC700 has a good enough charging rate and feature set. So I’ll stop introducing more chargers. I’ll also thank NLee the Engineer for so thoroughly reviewing these and many other chargers on Amazon.

How Do You Store Batteries?

Storing batteries at high temperature is not a good idea as it causes them to discharge at a faster rate. So be sure to store at room temperature or lower, preferably in a dry place.

Some people store batteries in their plugged-in charger. That works fine so long as you have a quality smart charger that senses when a battery is full. You can destroy batteries with a low quality charger that overcharges. For this reason, don’t use an old charger unless you’re certain it’s “smart” enough to sense when a battery is full.

I used to store batteries in a smart charger to keep them full. Then I had a kid. Toys accumulated.

Now, we have many devices that use batteries. Way too many. I occasionally swap out more than 10 batteries in a single week. In fact, it was this massive increase in battery activity that got me thinking about AA batteries in the first place.

So I have a bunch of charged spares, primarily AA and AAA. I store them in this inexpensive, wall-mountable battery holder which includes a battery tester:

Range Kleen 82 Battery Storage Organizer Rack Holder/Tester

Spread the Word About Low Self-Discharge Batteries

AA and AAA batteries are used in large quantity thanks to digital cameras, toys, flashlights, and a whole host of other gadgets. Since 2005, battery management has become simpler, less expensive, and better for the environment thanks to Eneloop and its low self-discharge battery competitors. Yet, most people have never heard of them. Therefore, single use Akaline batteries and high discharge NiMH rechargeable batteries continue to dominate the market.

I’d like to help change that. Hopefully, this article will help. You too can help. Here’s how:

  • Consider gifting one of the battery/charger combinations described above.
  • Point your friends and family to this post.
  • Most importantly, replace all of your existing batteries with low discharge batteries, as follows:

Buy a few 8 packs of Eneloop 1500s the next time they go on sale. Condition them. As your Alkaline batteries die, one by one, swap in your low self-discharge substitutes.

Once you’ve swapped out your last Alkaline battery, go to the local hazardous waste faculty to drop off your dead batteries. Take a good look. You won’t be seeing this hazardous waste facility for another 83 years.

Author: Joe Golton

I’m a dad with a son who loves baseball. Professionally, I’ve been a software developer, investor, controller, and logistics manager. I now make my living from this blog, supplemented with occasional consulting gigs.

28 thoughts on “Best AA Batteries That You Never Heard Of”

  1. To keep the size of this post manageable, I omitted a number of minor technical details. Here’s one example:

    Technically, Alkaline batteries are not hazardous waste. However, to simplify collection, many municipalities in the U.S. encourage people to take all batteries to a hazardous waste facility, since most people have no idea which batteries are hazardous, and which are not. For more information about hazardous waste classifications for batteries, see:

  2. Hi Joe,

    U r the Battery champion. Very nicely written article with very good information about batteries. Thank you so much for sharing these information. I will definitely buy a set of Eneloop for me 🙂

  3. What do you recommend for rechargeable low self discharge 9 Volt batteries?
    (and a corresponding charger for 9-Volt batteries)

  4. Harish – Don’t use a rechargeable 9v battery in a smoke detector, because the voltage in rechargeable batteries is lower than Alkalines, and that will cause the smoke detector to “beep” soon after inserting the battery (maybe even immediately). Alkaline batteries generally start at 1.5v and stay there for a significant fraction of the life of the battery. A 9v battery has 6 cells for a total of 9v. But when NiMh is used, the total is usually around 7.2v to 8.5v to start with and will quickly drop to 7.2v.

    However, if you want to use rechargeable 9v batteries for other purposes that can handle 7v, here’s a good but expensive charger for 9v, C, and D (sometimes goes out of stock):

    Rayovac (PS3) Universal Smart Battery Charger

    These 9v rechargeable batteries get pretty good reviews:

    4 pieces of Tenergy 9V 250mAh NiMH high capacity rechargeable Battery

    And here’s those same batteries bundled with a mediocre but very inexpensive charger:

    Tenergy TN141 2 Bay 9V Smart Charger with 4 pcs 9V 250mah NiMH Rechargeable Batteries

    I have not personally tested 9v batteries so I am simply speaking from others’ recommendations and my general knowledge of NiMH batteries.

  5. Hope Eneloop comes out with 9-Volts someday but there seems to be not much of a market for them.
    It’s unfortunate because many audio products use 9-V. As many as 7 can be used and thrown away in a small weekend event.

  6. Joe: thanks for this.

    My tuppence:

    Information overload, not helped by your choice of information-followed-by-link (I eventually realised that my brain was expecting each link to be a header for the following text, but even when I knew that it still didn’t help much).
    Is there a way of telling if a charger is a ‘smart’ charger, or not?
    I think this article illustrates well how competition in the marketplace can be a disservice to the customer, by creating so much conflicting choice that one (ok, me) thinks “to hell with this, I’ll just go with a brand name I know” 🙁
    One of the links (I didn’t test them all) in your article points to an item that is currently unavailable. Information gets stale so fast 🙁

    OK, that’s fourpence; and I hope it’s taken as constructive criticism, because I really do appreciate your attempt to inform.

    (s) Confused, England.

  7. Joe – Thank you for a great treatment on these eneloops and the chargers that make them go. I have been using an older quick charge ray-o-vac NiMH technology that are showing their age as well as their rapid self-discharge rates. I will move to eneloop very soon based solely on what you’ve told us. Your writing style is clear, you make the technical stuff understandable to non-techies, and your enthusiasm and passion shine through in the stuff you write. Best of luck to you, now and always. I hope to cross paths with you someday out there in the worldwide web!

    Mark Strelecki
    Atlanta, GA. USA

  8. awesome stuff, thank you all, My question, Is there any reason I can not charge HSD batteries in a La Crosse or other unit? and can I charge HSD batteries and LSD in the same unit at the same time? I use a head lamp 14 hr a day with 3 AAA batteries and it eats them like mad! so I think I need a couple of sets of HDS and a smart charger?

    thank you for your comments

  9. Iain – I assume HSD means high self-discharge. Headlamps are the perfect application for HSD batteries.

    All that matters in mixing batteries with chargers is the chemistry. Most HSD rechargeable batteries sold today are NiMH and therefore most chargers sold today support that chemistry. It doesn’t matter whether they are HSD or LSD, and it is fine to simultaneously charge a mix of HSD and LSD batteries in the same charger.

    However, make sure it’s a smart charger with independent charging bays, such as any of the recommended chargers above. Without independent charging bays, in each pair of batteries only one will get fully charged.

  10. I am so glad I found this article. It is packed with so much information, I am going to have to read it a few more times. Even the questions are informative. Thanks for taking the time to put together such a great article.

  11. Thank you. Very nice information. I purchased them as a kit – running nice.

  12. Thanks for your very detailed review of the eneloop batteries. I’m new to the low discharge battery world and just purchased some from Costco. The minimum rating listed on the battery is 1900 mah. I’ve read some reviews and tests that exceed 2000 mah. In order to get the most out of the batteries, I’m using the “Break-in” process on the maha powerex charger. After loading the batteries, it asks what the maximum mah should be. My inclination is to input 2000 mah, however given the reviews of some users who get beyond that, would it be dangerous to input 2100 mah? Thanks for your help!

  13. Hi Darren – You have the new Eneloops. In my testing they will always attain at least 2000 mAh but never 2100 mAh. My highest is around 2080mAh. I don’t own a Maha so I don’t know what would happen if you put in a maximum of 2100 mAh. If it does a full discharge/recharge more than 4 times then it’s going on too long. I think 2000 mAh is safe.

    Alternatively, you could simply do a full discharge/recharge 4 times. In my experience, the battery capacity increases a lot with the first discharge/recharge, a little with the second round, and only a tiny bit on rounds 3 and 4. In fact, I sometimes see the capacity go down by tiny amounts on round 4, which to me indicates that it has stabilized and gotten into the realm of measurement error.

  14. Joe,

    Is there anybody that makes a charger VERY similar to the LaCross Chargers that will also do “C” & “D” size batteries?
    I currently have 2 LaCross BC700 chargers and Love all the options that they offer, especially the Automatic “Refresh” (Condition) mode.



  15. Thanks for writing this Joe. I think the article pretty much covers a good portion of information about NiMh rechargeable batteries especially the Sanyo eneloop part.

    Have you used the eneloop “Lite” series? What do you think of them?

  16. Glad you found the post helpful, Mike. I’ve never used or even researched the Eneloop lite series. No Amazon reviews so I’m guessing they just came out.

  17. When is the best time to break in pre charged batteries?
    Straight out of the packing or after a discharge? Powerex/Maha recommends break in for new batteries but that involves a charge/discharge/charge. Does charging on top of the pre charge do any damage tp the battery?

  18. So far as I know, you can break in pre charged batteries any time. But may as well do right out of package just as Maha recommends because it will allow the battery to hold more charge and therefore go longer between charges.

    There’s no danger to the battery so long as you use a high quality charger such as Maha or La Crosse that cut off when battery is fully charged.

  19. Thanks Joe. I am using the the Powerex MH-C9000 and am very pleased with it as it allows me to keep tabs on each individual set of batteries which are in the main pre charged.

  20. My smoke detectors use AA batteries rather than 9-volt. Does the same thinking apply — that eneloops should not be used in these smoke detectors?

  21. I’m still a little confused. What appliance are Eneloops NOT appropriate for, besides smoke detectors? Are Eneloops appropriate for TV remotes? Clocks? Are they ok for flashlights, but not emergency flashlights? Those seem to be the items that we mostly use batteries for.

  22. I would avoid using Eneloops for smoke detectors, but they can be used for almost anything else. If you search the comments above, you’ll find one about smoke detectors where I talk in detail about the voltage issue where Eneloops will operate at a slightly lower voltage than Alkeline batteries, thus triggering low battery warning beeps. Eneloops may also be problematical in other device that depend on the slightly higher voltage of Alkaline batteries. Thankfully, such devices (apart from smoke detectors) are few and far between.

    Eneloops work fine in TV remotes, clocks, and flashlights (but Alkaline also very good in these applications – I prefer Eneloop so I don’t have to keep rebuying batteries). Alkalines perform particularly poorly with high drain devices such as digital cameras so that is why I highlighted Eneloops for that case – but they can still be used for all the rest, which is what we do at home (apart from smoke detectors).

  23. I got caught recently buying rechareable batteries from Hong Kong off ebay. I ordered some 9v batteries for a little project I had going – and when I got the batteries they were about 1/3 the weight as ‘normal’ 9v batteries and lasted about a 1/3 of the time – Once bitten twice shy.

  24. I would stay off Flea Bay (E-Bay/LOL) as there have been reports of people being misled as to what they were buying vs to what they were getting. There have been scores of people buying 3000MAH AA batteries only to find that the actual capacity they got was worse than a NiCad AA, and sometimes even lower than 150mah in some cases. They were completely useless. I got a Maxxus brand AA once that was rated at 3000mah, but the actual capacity never exceeded 1500MAH.

Comments are closed.