This article has been replaced with a 2018 AA Batteries update, due to various product changes and other developments in this category.
Not much changes from month to month or even year to year in the world of AA batteries and chargers. My two articles on the subject continue to be relevant despite their age:
However, there have been many minor developments in the market over the past few years. Newer generations of low self-discharge batteries have been released. My favorite inexpensive battery chargers were discontinued. I’ve also heard a few questions asked repeatedly, the most important being, “When is it better to use Alkaline batteries instead of NiMH?”
This site has become a significant source of information about low self-discharge batteries and chargers, so it’s time for an update.
Before launching into updates, here’s a brief recap of my prior articles:
Most people would do well to use low self-discharge NiMH batteries in nearly all situations that require AA or AAA batteries. Eneloop is a trustworthy brand for this type of AA battery. For best battery performance, you’ll want a high quality battery charger from La Crosse or Maha.
In the rest of this post I won’t repeat previously covered material. If you want the reasoning behind the conclusions, read the two posts linked above.
Minor changes to Eneloop and its low self-discharge competitors
I like Eneloop quality, and therefore I like the Eneloop brand. Historically, most Eneloop competitors have competed on price, not quality. Eneloop’s claims about how much charge the battery holds have always tested true, as have other marketing claims they make, while the same is often not true of the competition.
The competition has improved, and there are now some worthy alternatives to Eneloop, though in many cases they are just re-branded Eneloops. Duracell and Amazon are two examples of brands that offer re-branded Eneloops. Despite the improved competition, I continue to stick with Eneloop or re-branded Eneloops as the overall lifetime cost of this type of battery is not so high.
The Eneloop battery product line has evolved from the first generation launched in late 2005. In my opinion, new parent company Panasonic has over-complicated the Eneloop line with too many versions and too many generations of minor changes. To keep it simple, I’ll recommend just two versions for AA batteries (and the same two for AAA), and one charger/battery combo. I’ll also include the lowest cost, quality alternative I’m aware of in each category.
Eneloop is still the name for the basic version, which has gone through 4 generations. Each generation has increased the number of times the battery can be recharged and improved the rate of self-discharge, though most of the improvement occurred in the 2nd generation in 2010. First generation Eneloops are still fine batteries—the only reason to consider disposing of such batteries is if they no longer hold much charge. With typical use, this won’t occur for decades.
The number of lifetime recharges increased from 1000 to 1500 with the 2nd generation, and the rate of self-discharge improved. Subsequent improvements have been minor, with maximum recharges now at 2100. There’s no advantage to prior generations, so when purchasing additional Eneloops, go for 4th generation versions.
2000mAh regular capacity Eneloops
Less expensive alternative:
The above batteries are fine for most ordinary applications but in high drain devices such as cameras, you can run through batteries very quickly. In such cases you’ll want higher capacity batteries (typically 2550 mAh for AA batteries, a 550 mAh increase over the regular Eneloops). However, they cost more and only last for 500 recharges. They are also slightly fatter, so they may not fit easily or at all in some devices.
Eneloop called its first version of high capacity battery “XX” when it came out May 2012, but the 2nd generation released in 2013 is now called Panasonic Eneloop Pro.
2550mAh high-capacity Eneloops
Less expensive alternative:
It’s great to see that Eneloop has finally come out with a 10AA/4AAA package that includes a high quality charger (a first). This would make a nice gift for parents of toddlers, who will easily use this many batteries over the next few years:
Another Eneloop package option:
An inexpensive charger that does the job
There are literally hundreds of chargers on the market, including some which are bundled with batteries. However, very few are worth purchasing. My intention was to list 3 quality, inexpensive chargers in this section but my prior favorites were all discontinued. There is currently only one low cost model I recommend:
This Panasonic Eneloop charger (which I discuss in great detail in Best Low Cost AA Battery Charger) is the same one included in the combination package at the end of the prior section. It’s simple. It’s low cost (usually $14.99). It has four battery bays. Individual LEDs indicate when an individual battery is fully charged. Most importantly, it has the minimum needed “smart charger” features to be good: proper circuitry to detect when a battery is fully charged, and independent channels for each charging bay.
The vast majority of inexpensive models charge in pairs. When one battery is full, they both stop charging. This results in partial charging of every other battery. Use one of these cheapo models and you’ll notice your batteries don’t last so long. All it takes is the voltage from a single battery dropping below a certain threshold, and you’ll need to recharge the entire set from a device. The fault is with the paired bay charger, not the batteries.
So what’s the drawbacks to buying this inexpensive Panasonic model? It charges slowly, at an average rate of 300mA for AA, and 150mA for AAA. It takes over seven hours to charge fully depleted AA batteries. There is no option to charge faster. There are no options of any kind.
The next section covers 4 premium options which can charge at faster rates. These models also have many additional features and optional settings. You’ll want to consider these if you have a “need for speed”, have over a dozen AA or AAA batteries, or you simply like to own the best. Any of the premium chargers can be used as simply as the Panasonic charger—just pop them in and remove when fully charged. But they can also do more.
4 Premium Battery Chargers
The two most well known brands among premium chargers are La Crosse and Maha. I have personally tested two La Crosse models but none from Maha or newcomer Opus. My knowledge from these other models comes from extensive reading. I’ll briefly summarize what I know here. For more information on what makes for a great charger, especially La Crosse, see prior charger post.
Premium chargers offer a few advantages over the simple charger I discussed above: testing, conditioning(refresh), big displays, and selecting different charge rates per battery bay.
There are differences among these 4 models, including maximum charge rates, reviving heavily depleted batteries, and ease of use. I prefer La Crosse for the ease of use, but for those who don’t mind extra button presses and a more cumbersome user interface, the Maha model is arguably better. Opus doesn’t have as much of a track record, but the Opus model I recommend may actually be best of breed.
The first and least expensive model I recommend is the La Crosse BC-700. It typically costs around $38-$42 and does pretty much everything the more expensive La Crosse models do except charge batteries at a rate higher than 700mA. It also does not come with any batteries or accessories beyond the charger and power supply.
To maximize battery life, it’s preferable to charge AA batteries at 500mA and AAA batteries at 200mA, though going over every once in a while by a little won’t have much of a negative impact. But this means that fully depleted batteries can take well over 5 hours to charge. If you sometimes need to charge batteries in a rush, or can’t find this model for less than $42, you’ll want to get one of the other three models.
There are several more expensive La Crosse models that offer higher maximum charging rates of 1800mA. These models also include a carrying case, adapters for C and D battery sizes, and low quality NiMH batteries (4 AA, 4 AAA), which are not included with the BC700. However, I can only recommend one of these three models, the BC1000.
I have been using a BC900 for 6 years and a BC1000 for 2 years. I cannot recommend either the BC-900 or the BC9009 La Crosse models because there have been many reports of overheating on both models, when charging at the highest rates. In extreme cases this can melt batteries, creating smoke or possibly even a fire.
The BC1000 model contains additional circuitry to prevent overheating, so you get (optional) higher charging rates without safety issues. The BC1000 model typically costs $55 – $60.
The similarly-priced Maha MH-C9000 offers the same suite of capabilities plus a few extras—more flexibility, a little more control, slightly higher maximum charging rates, a larger size, and automatic revival of totally drained batteries. This last is particularly helpful, as the La Crosse models display a cryptic “null” message when heavily depleted batteries are inserted, and according to the manual that means the batteries are defective. Usually they are not, and can be revived, but doing so with the La Crosse charger is cumbersome. (I’ve found that a “null” battery will usually revive after a few days of resting in a plugged-in La Crosse charger.)
I personally have no interest in the Maha model because the extra control and flexibility require a more difficult-to-use interface, sometimes needing many more button presses than the La Crosse to do simple things such as increasing the charge rate for the 4 batteries you just inserted. Also, its display rotates through data over 48 seconds, while La Crosse chargers allow you to select which data you want to see. If you’re not bothered by the user interface and extra button presses, this charger is an excellent option.
Last, but definitely not least is the Opus BT-C2000. Opus seems to have overcome various issues with prior models with a 2014 firmware upgrade to version 2.1. If you do get this model, make sure you see the number “2.1” or higher briefly displayed on the leftmost column when turning it on.
This model has most of the advantages of the other three models combined into one package: It’s easy to use, offers great flexibility and control, and has a big display. As if that weren’t enough, the price has often dipped below $40 since August 2014. The only thing not to like is that the maximum charging rate of 1400mA is not quite as high as the La Crosse BC1000 or the Maha MH-C9000.
Concluding remarks (and when to use Alkaline)
If I sound very enthusiastic about low self-discharge batteries and quality chargers—it’s because I am. Unfortunately, the value proposition for Eneloops and decent chargers takes time to explain. For small purchases like this, most people won’t take much time to think about their decision. The result is that most people experience rechargeable AA batteries as an annoying hassle.
Once you do realize how good this type of battery is, the only question in your mind will be:
When would I ever want to use a disposable, Alkaline battery?
Answer: when you need higher voltage. Rechargeable NiMH batteries are approximately 1.2V when fully charged. Alkaline batteries provide over 1.5V when full and over 1.2V for a sizable fraction of their life (typically until they’re below 2/3 capacity, though some last longer).
Devices that require higher than 1.2V are annoying not just because you can’t use rechargeable batteries, but also because Alkaline batteries won’t last too long before the voltage output drops too low, even though they have enough charge left to power other devices. Most people don’t realize that and throw them out.
I recommend using Alkaline batteries in smoke detectors, because some require higher than 1.2V. How can you know if you have such a device?
Another case for using Alkaline is in devices that operate differently depending on battery type. For example, some flashlights shine brighter with fresh Alkaline batteries than they do with NiMH batteries.
The other question one might have is when to use high discharge NiMH batteries. The answer is never, thanks to the availability of high capacity, low-discharge NiMH batteries such as the Eneloop Pro.
Retailers rarely offer low self-discharge batteries for sale. The only store in which I’ve found such batteries is Costco. Why are these batteries so hard to find in physical stores?
I don’t really know. But if I had to guess, it’s for the same reason it’s much easier to find Teflon-coated pans than cast-iron skillets:
Eneloops don’t need to be purchased much. Once you buy them, they last decades. Not great for repeat sales, and therefore not great for retailers. But great for the rest of us.