Why Rechargeable Batteries Are Rarely Cost Effective

I was standing in line at a local electronics store the other day when I struck up a conversation with the guy ahead of me who had a basket full of battery chargers and AA rechargeable batteries. It turns out he had decided to replace all of the batteries in his house with the rechargeable kind. Between the batteries and the chargers this guy plunked down over a hundred bucks!

He was so proud, telling me about all the money he was going to save.

I didn’t have the heart to ask him if he had the same typical electronic devices found in most homes, because if he did then he probably ended up spending a lot more money than he should have.

Rechargeable Batteries Aren’t Always Cost Effective!

I realize many people want to convert to rechargeable batteries for environmental reasons, which is fair enough. But the truth of the matter is this: when cost is the primary discriminator, low current-draw devices simply don’t warrant the extra expense of rechargeable batteries. That’s because the batteries of low current-draw devices are typically changed so infrequently that the payback period for equivalent rechargeable batteries would be too far long to justify the investment!

For example, it makes much more sense to use traditional alkaline batteries for low-draw devices like your wall clocks, radios, smoke detectors, programmable thermostats, and remote controls because they lose power at a much slower rate than rechargeable batteries.

And because traditional alkaline batteries can hold a charge for years when not in use, they are also the better choice for items that may sit unused for long period of time, like your alarm clock back-up battery and emergency flashlights.

When it comes right down to it, these low current-draw and/or low-use devices make up the great majority of battery-driven products in the typical home.

Okay.   So When Do Rechargeable Batteries Make Sense?

Rechargeable batteries are really intended for moderate to high current-draw devices that get at least moderate use. Typically, these are devices that require a battery change every 30 to 60 days.

In my house the only item that clearly met that criteria and, therefore, justified the added up-front costs of rechargeable batteries, was the kids’ Wii gaming system. That is a perfect example of a high-use device where rechargeable batteries will save you a lot of money in the long run.

But for my household those are the only items where rechargeable batteries make sense.

“But, Len, what about my wireless keyboards and mice? Those get a lot of use!”

Well, as my article on the practicality of wireless mice and keyboards noted, rechargeable batteries didn’t even make financial sense for those devices, based upon my battery usage over an 18-month period — I only spent a little over $18 on replacement batteries during that period. But a set of eight good rechargeable AA batteries (five for the mouse and keyboard plus three spares) would set me back roughly $24. Add in the cost of the charger (a good one can run upwards of $40) and you can see that the payback period on the rechargeable batteries becomes a real issue. Remember, rechargeable batteries eventually go bad too, so you’ll need your batteries and charger to last at least until the payback period is reached if you want to recoup your costs in a reasonable amount of time.

How Do I Know Which Type of Rechargeable Battery to Buy?

If and when you decide you want to buy rechargeable batteries, you’ll need to know that there are essentially four types to choose from: nickel metal-hydride (NiMH), nickel cadmium (NiCad), rechargeable alkaline, and lithium ion.

NiMH rechargeable batteries typically perform better than NiCads and are free of toxic heavy metals. Generally speaking, NiMH is the best all-around choice for most rechargeable battery applications. As an added bonus, most NiMH battery charger systems can accommodate NiCad batteries too (although the opposite is not true).

NiCads are being phased out in favor of NiMHs not only because they are losing the performance war, but also because of their inconvenience; the heavy metals used within the NiCad are toxic and require special disposal needs.

Rechargeable alkaline batteries have only two real advantages over NiMHs and NiCads: low cost and no need for special recycling. Otherwise, their long-term performance and recharge characteristics make these batteries a poor choice. Rechargeable alkaline batteries also require a special charger, which reminds me: don’t ever confuse rechargeable alkalines with the typical disposable alkaline batteries that are sold everywhere from 99-cent stores to the local grocery market – although some people do it, those batteries cannot be safely charged.

Lithium Ion batteries have great performance and can go unused for long periods without losing their charge. The big drawback is their price; not only are lithium ion batteries much more expensive than other types of rechargeable batteries, but they also require a special charger. Use them for rarely-used or high-drain devices like laptop computers, digital cameras, cell phones or portable televisions.

To help you decide which rechargeable battery is right for you, here is a trade summary I put together of the four basic options:

Click on the image to enlarge it.


Some Final Thoughts and Recommendations

  • A bad battery charger will prematurely age and greatly shorten the lifespan of your rechargeable batteries. Cheap chargers work too quickly, thereby heating the batteries, which damages them over time. Good chargers will keep your your batteries from getting too warm.
  • Batteries should always be removed from their chargers after recharging.
  • More expensive battery chargers extend the life of your rechargeable batteries by properly monitoring and controlling the charging process; many also shut off when charging is complete.
  • If you do use rechargeable batteries, be sure to keep several spare batteries ready to go at all times so you can swap them out when needed.
  • If you do choose to swap out all of your devices with rechargeable batteries, you can spread out your initial costs by replacing only the moderate-use devices first.   You can then buy rechargeable batteries for the low-draw devices as needed.
  • For info on NiMH rechargeable batteries and battery chargers, check out this article from MetaEfficient.

To Summarize…

Rechargeable batteries are great for moderate to high use devices that drain batteries quickly, but they are not cost effective for low current-draw and/or low-use devices – and it is the low current-draw devices that tend to make up the great majority of battery-driven products in the typical home.

Hopefully, the gentleman I met at the hardware store has a lot of high current-draw, frequent-use devices at his house — otherwise, he probably made a big mistake.

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  1. 1

    Dean says

    Nice article, Len.
    Why are there some devices that refuse to work with rechargeables at all? I have some kids’ electronic toys that won’t function at all unless they have disposable Alkalines. Some that come to mind are LED flashlights, blinky-noisy kids toys, etc. Maybe the cheap AAA rechargeables are to blame too. Can you recommend how to effectively compare price/performance on NiMH AA/AAA rechargeables?

    thanks, maybe topics for a future article…

    • 2

      Chuck S says

      Probably because NICd and NiMH are nominally 1.2 V and carbon-zinc and alkaline are 1.5 V.

  2. 3

    Len Penzo says


    I am going to put on my electrical engineering hat here to answer your question, but I will try not to get too geeky here… ;-)

    I’ll give a short answer to both your questions, followed by a more technical explanation.

    Short answer to question 1: The voltage drop on rechargeable batteries is often too high to get the needed peak power from the batteries.

    Technical answer to 1: Alkaline batteries have very high peak current ratings and good Watt-hr numbers (capacity). This is good for LED flashlights, which normally pulse the LEDs on and off at a high rate to get the brightness and avoid droop. Kids’ toys that have motors require high starting current and, therefore, alkaline are best for those applications too.

    Short answer to question 2: I think for home applications $/Amp-Hr rating is the way to go.

    Technical answer to 2: Normally, the battery industry compares batteries in this order of priority – energy density, cost per WHr, Amp-Hr ratings, pulse load capability (internal impedance), charge rate.

    Hope that helps! :-)

    • 4

      Matt says

      Not true about alkalines vs NiMH! NiHM batteries actually have a MUCH lower internal resistance than alkaline batteries. This means that NiMH batteries can supply a MUCH higher current than alkaline batteries. It also means that, although the open circuit voltage of alkaline batteries is higher than NiMH (1.5 vs 1.2), the voltage under a high current load is actually higher with NiMH batteries! In addition, NiMH batteries supply a more or less constant 1.2 volts as the battery is discharged, while the voltage of an alkaline battery drops with use.

      As far as rechargeables not working in some devices, this can only be the case in very low current devices. In these devices, a rechargeable battery may not produce sufficient voltage. However, in high drain devices, this will not be the case. Not only can rechargeables supply a higher voltage under a high current draw. But most devices designed for alkalines are actually designed to run on as little as 1.0 volts (since the voltage of alkalines tends to drop so sharply with use).

    • 5

      BC says

      What’s that about current and alkalines? You don’t seem to have taken internal resistance into account. Everything converts into a voltage divider. If the effective resistance of the device is high, like a wall clock – then the higher internal resistance of the battery isn’t an issue and nearly 100% of the voltage is available for the device. If the effective resistance of the device is low like with the peak operation of digital camera with flash, then there’s a severe voltage drop and a good portion of the power output of the battery goes into heating up the battery.

      The voltage drop on alkalines with high drain devices is severe. I used a multimeter on batteries in an old portable TV I owned. I could get about 3.5 hours out of either 3000 mAh alkalines or 1600 mAh Maxell (made by Sanyo) NiMH cells. When I measured the voltage, it was typically 1.61V for a fresh alkaline, but then maybe 1.1V measured when under load. For a freshly charged NiMH cell after settling down a few hours, I measured about 1.31V open circuit voltage, but about 1.2V when measured under load. After being drained, the alkalines would drop severely as the internal resistance increased. The NiMH cells still maintained decent voltage until they had a sudden voltage and internal resistance drop. In this portable TV, the alkalines would get extremely hot, but the NiMH batteries would barely get warm.

      The only issue is that some devices are only designed for the higher voltage of alkalines, and they don’t last very long until the voltage just craters.

  3. 6

    Richard says

    Hi Len,
    Nice job explaining the differences & economics
    Re the Alkaline/rechargeable debate, alkaline (and the older carbon-zinc) batteries have a terminal voltage of about 1.5V unloaded when good. Rechargeable NiMH and NiCad are about the 1.2V area. Some electronics won’t start at the lower voltage.

    Also, NiCad batteries are regarded as superior to NiMH (and Lithium Ion IIRC) for low temperature applications.


  4. 7

    vicaya says

    Wow, there are still significant amount of people who don’t know LSD (low self discharge, which maintains 80% of the charge in a year) NiMH batteries. Google eneloop to learn more.

  5. 8

    Len Penzo says

    @Richard: Thanks. And you are correct about the NiCad and Lithium Ion for low temp applications. Lithium ion is especially effective in this regard.

    @vicaya: You are forgetting the cost equation. Alkaline AA batteries cost 30 to 40 cents each. It makes almost zero sense from a financial perspective to justify paying approximately $4 per AA LSD NiMH battery and another $20 minimum for a charger – those rechargeable batteries would go bad before you ever reached the payback period.

  6. 9

    Peter says

    Also, I guess, the main point you’re making about monetary cost would apply just as much to environmental cost? The numbers will be different (I don’t know quite how they stack up, & would be interested to hear!) but the basic argument – that if the batteries are only being replaced rarely, then the one-time cost of changing over outweighs the reduction in replacement costs – seems to be just as valid.

  7. 10

    Smarty Pants says

    Good to know, but this article leaves out the convenience factor. It’s easier to have rechargeables on hand than to run to the store to replace the batteries for my mouse.

  8. 11

    Len Penzo says

    @Smarty: I think a lot of people would disagree with you. There really is no inconvenience at all if you buy the alkaline batteries in bulk, which you should be doing anyway. When I see the supply running low, I simply make sure I pick up more alkalines at my earliest opportunity. :-)

  9. 12

    Richard says

    Remotes have suckky range with rechargables in them because of the lower voltage.

    Also my cordless headphones will go louder with less distortion when run off alkalines. Shame the rechargable alkaline systems never got anywhere – I guess the 20 or so charges that you get out of them was not enough to swing most people to them.

  10. 13

    Jason says

    I actually just bought a Lacross BC-9009 Battery charger for $40 and 4 packs of Eneloop LSD batteries to replace my aging Energizer rechargeable setup. I think its a good investment for several reasons. First, everything seems to need batteries these days. 3 Wii remotes + 2 XBox remotes + 3 remotes for the entertainment center + Keyboard/mouse + Wii Fit Board + kids toys + other misc items. Second, is that to buy batteries in bulk, I would have to travel 25 miles to the nearest Wal-Mart — Highly inconvenient. Third, it is the environmentally right thing to do. Instead of landfills filling up with batteries, my batteries are charged by our town’s wind powered grid.

    Once you get over the hump of buying the charger, I think it makes more economical sense to get the rechargeables. At the end of the day, the rechargeables are going to outlast the disposable kind.

  11. 14

    Erik says

    Provacative article, but I am not buying into your economic argument. Look at your keyboard/mouse example. $18/year disposable vs $24 for rechargeable (but You included 3 extra which is not a fair comparison – should be 5 at $15. Just after 1 year you are ahead on batteries) also the rechargeable last much longer than one year. My experience is easily 3 or more years. And if you are using rechargeables for all your battery needs the charger costs are spread over more batteries making the charger costs insignificant.

    Regarding convenience, it does make since to have some disposables on hand for when your rechargeables run down and you need battery power while your are charging.

    So, the guy in front of you was probably doing it right. Buying a lot of rechargeables which means he will spread the charger costs over more batteries.

  12. 15

    CTT says

    My MP3 player go through 1 AAA every two days and have done so for the last three years.
    Price comparison (local prices):
    4x LSD NiMH AAA’s: $8.50 + charger $12 = $20.50
    500x Alkaline AAA’s: $160

  13. 16

    Klaus says

    There also is another aspect to consider. Manufacturers still develop devices that do not make proper use of rechargeable batteries and that’s plain wrong. Devices should be designed in a way that they work perfect on rechargeables but can accept Alkaline batteries should you need to. The form factor of the rechargeables (and their Alkaline replacements) may not be perfect, but at least it is standardized. Not so for a whole range of devices (like mobile phones) where even within the product range of a single manufacturers you are faced with a multitude of proprietary rechargeable batteries which cannot be re-used/shared between devices AND device specific chargers. Totally ridiculous. That should be penalized IMHO. How environmental friendly is that? I also want to second another point someone brought up here: The more devices one uses that employ standardized rechargeable batteries, the less significant the charger costs become. We are a 5 head household with so many battery powered devices that I have two charges (one for 4x AA and one for 4x AAA types) running 24/7. Whenever one needs any they are swapped out.
    I opted for chargers that take their time charging because my understanding is this is more beneficial to the lifespan of the rechargeables due to the chemical energy storing process being less aggressive and more similar to the discharging pattern (so this might be a misconception of mine). Choosing the slow chargers, however, required some convincing of myself, because recharging cycles of 1hr only just sound very convenient. But when you need batteries, even a 1hr wait for charging is too long. Hence the setup of having two charges filled with rechargeabels all the time. I currently use NiMH. Why? Because I have a whole bunch of them. Once they die out on me, I’ll switch to the next best technology out there then — and probably buy two new suitable charges again.

  14. 17

    Andrew says

    Where did you get the ridiculous figures you’re using for the cost of NiMH batteries? I have a whole drawer full of the things and I never spent more than $1.50 on any of them (they’re all name brands — Duracell, Rayovac, and Kodak). The Wal-Mart by my house sells 4-packs for $5. The alkalines they sell run about 80 cents each when purchased in the large packages, or about $1 each when purchased in smaller quantity.

    I’ve used the same set of NiMH batteries in my wireless keyboard for about 3 or 4 years (8 or 10 charges) and they’ve paid for themselves in that time. I use NiMH in everything except the smoke detectors and I’ve only purchased one package of batteries in the last few years. I’ve got Logitec Harmony remotes which will burn through a set of 4 alkalines in less than 60 days.

    The total cost of all my batteries and the charger was around $50. It may have taken a while, but it has definitely paid for itself by now! As long as you get 3 or 4 uses out of each battery the cost is justified except for low drain+constant use items like a wall clock. Do people really leave batteries in things they only use occasionally when not in use? I know I don’t. Unless I use something every day, the only time it has batteries in it is when it’s in use.

  15. 18

    Matthew says

    I go through batteries like crazy and it just doesn’t make financial sense for me to buy alkaline.

    I’m having good luck with Tenergy Nimh AA & AAA batteries at well under $2 each. And you only have to buy the charger once. Sure, they might not work in a clock but I have exactly one clock that needs batteries. I have so many more devices that can use rechargeable batteries – cameras, tv remote controls, xbox and wii controllers, rc toys. Why on earth would I go buy batteries just to throw them away.

    Even in low draw applications these rechargeable batteries will still be working long after I throw away 4 sets of alkalines (equal cost wise).

  16. 20

    Steve says

    I feel I need to correct one area you have commented on, and that’s the proper cell choice for LED flashlights.

    Contrary to your assertion in a previous post, most LED flashlights do not ‘pulse the LEDs’. They may employ PWM at lower intensity levels, but on high they must be considered high-current, high-drain devices. Many modern high-brightness LEDs demand more than 1 amp of current in flashlight applications, and will run at a significantly lower brightness if alkalines are used.

    Most flashlight hobbyists (and yes, there is such a thing) favor LSD NiMH cells for use in high power lights. They can deliver the high current required, have low self-discharge rates for storage purposes, and perform better at low temperatures than alkalines. NiMH cells also have a flatter discharge curve than alkaline cells, and can provide a form of regulated output in LED lights that do not use a regulation circuit. Additionally, NiMH cells have the benefit of not leaking over time and potentially ruining an expensive light.

  17. 21

    Len Penzo says

    @Richard: You are correct about the lower voltages of NiMH. This is also the reason why for devices that require more than 2 or 3 batteries, disposable alkalines (with their higher voltage) are often the best solution.

    @Jason: I don’t blame you for using rechargeables in your situation. Just make sure you buy the best charger you can, otherwise you will prematurely age your batteries. :-)

    @Erik: The main reason why I selected 8 batteries rather than 5 for the example is that the NiMH rechargeable batteries come in packs of 4 and 8. I do not know if you can even buy them individually and if you could the price would naturally be more expensive anyway.

    By the way, it is a fair comparison if the person buying the batteries (me) wants the convenience of always having fresh batteries available as replacements when the other batteries run down. ;-)

    @CTT: If I used my MP3 player enough, that would certainly be a good candidate. I’d be wary of the charger you have. That price seems to suggest you have a model that charges too quickly – if those batteries are warm to the touch when charging you really should find a better charger.

    @Andrew: My $24 price for rechargeable NiMH was based upon the cost for an 8-pak of 2700 mAH PowerEx batteries – arguably the best performing rechargeable NiMH on the market. I’ll wager your price is for the 2000 mAH Eneloop LSD NiMH. And that price is conservative, by the way, as they retail for $30. Of course, comparing the Eneloop to the PowerEx is comparing apples to oranges, but if you are interested I can send you some interesting test results that compared numerous NiMH batteries (mixed bag, LSDs and performance) and I agreed with their conclusion that the PowerEx was the better alternative. Then again, it all comes down to your applications.

    BTW, I can get a package of 36 AA Duracel alkaline batteries at Costco for 40 cents a battery.

    As for leaving batteries in things that aren’t used over long periods, I prefer to keep my emergency flashlight “loaded” at all times; who wants to look for batteries in a power outage?

    @Matthew: In your case, rechargeables seem more than reasonable. I just don’t think your case is typical. Yes, you will eventually get your money back using rechargeables batteries for low-current draw devices – assuming your batteries and/or charger don’t die before the payback period is reached. I have electronic clocks that require a new alkaline battery once every two years. At 40 cents per alkaline, the pay back period is over 6 years away – and that is not even considering the effects of the time value of money.

    @Michael: I don’t think Sanyo’s LSD Eneloop batteries are worth it for low-drain devices. From a financial perspective they are by no means any more cost effective than alkalines for the typical household. See my comment to Matthew for just one example.

    @Steve: Thanks for the correction – I know better than to argue with the flashlight enthusiasts! :-)

  18. 22

    lens42 says

    This article might be correct for old NiMH cells, but the conclusion is very wrong once cells like Sanyo Eneloop are considered. They self discharge only 15% per year, which means they are completely suitable for all but the lowest current applications. Since buying Eneloops, I have not purchased an alkaline AA cell in over a year. The only item still with alkaline is my TV remote. Flashlights, video-game controllers, digital cameras, and more are all on Eneloops and work great. I have never paid more than about $2 per cell.

    Eneloops don’t have have the 2700mA capacity of the cells used for comparison. They are only 2000mA/hrs but they are still superior because of the low self discharge. Before these cells, NiMH were unusable in most cases because after you charged them, and they sat for a while, you couldn’t be sure they were still full.

    The “low voltage” knock on NiMH is often not valid because NiMH (both Eneloop and older types) cells have lower resistance than alkaline, so even though the open circuit voltage is lower, the cell voltage doesn’t drop as much when it gets hit with a load. This is why NiMH have always worked better than alkaline AAs in digital cameras. Alkalines drop a LOT when the flash recharges, and trigger the “dead battery” indicator.

    I strongly implore readers to get a pack of Eneloops and a charger and stop filling the garbage with alkaline AAs. I am talking from direct personal experience. These cells work. Len is WAY off base.

  19. 23

    CanAmSteve says

    Great info, but as in the case of car ownership (not very cost-effective if public transport is available) once the decision has been made to purchase a good charger the equation changes, and that should be explored.

    I do a fair amount of photography and in flash units rechargeables (NiCads esp.) make more sense economically. Since I already have a sophisticated, multi-battery charger, my criteria for deciding what to use rechargeables in negates the cost of the charger.

    That being said, about the only other things I do use the rechargeables in is a wireless keyboard and some wireless speakers. I buy no-name AA and AAA alkalines in bulk (but have yet to find D cells). For low-temp use, lithium batteries work well but are not available in all sizes.

    I also tend to use alkalines in safety equipment like smoke detectors. As I replace the batteries before failure on a yearly cycle, I’m not sure how long NiMH cells would last, but the bother and possible risk are not worth it, IMHO.

  20. 24

    Len Penzo says

    @lens142: The conclusion of the article is that the batteries are rarely cost effective. Even if the NiMHs are LSD, the payback period is far too long to justify the expense of converting from cheaper alkalines. I stand by that assessment.

    @CanAm: Yes, if you ignore the cost of purchasing the charger then the equation changes, but why change the equation? The purchase price of the charger must be considered in the analysis. :-)

    Thanks to both of you for your comments. :-)

  21. 26

    Steve B says

    This article only works if you look at a payback of 18 months. My oldest rechargeables are approaching five years old and are used in everything from kids toys (low to moderate draw/use) to keyboards and mice to commuter bike lights (high draw, daily use). I don’t know if cycling them through a variety of applications matters, but in my case I haven’t bought a battery or charger in over three years.

  22. 28

    Ted says

    You have some good points. There are uses for alkalines and there are uses for rechargeables. I don’t think it is fair to only use the retail price of NiMH’s and then to use the “on sale” price of alkalines to make your cost comparison. Either use retail price of both or on sale price of both. Also, 18 months for the wireless mouse seems arbitrary. It seems like you would use it for 3 years (and even then might replace it with another one that also uses batteries) and for the second 18 months the rechargeables are free.

    I agree on buying a good charger, though you can get a good charger for $25 (on sale or at Amazon) that will 1. charge batteries individually instead of in pairs, 2. charge batteries at the non-damaging rate of 1-2 hours, 3. cut off when the battery is full. The $40 chargers are more versatile, but might be overkill. However, it is almost impossible to find good chargers in stores.

    Lastly, I think low self-discharge batteries can change things. They will be ready when you pick up the digital camera or flashlight after three months or a year since the last time you used it and you can take more pictures or shine the light longer than with alkalines. And they won’t corrode like alkalines that sit around for too long. If you get them on sale, you can stretch the 3-month cycle you talk about to 6-9 months and still be economical. LSD cells can be recharged thousands of times when using a good charger. And they will easily last 5 years or more.

  23. 29

    Len Penzo says

    @Steve: I don’t quite understand your first sentence. The payback period is not the variable here. It is determined based upon the costs of the respective batteries being compared. What I think you are trying to say is that if your batteries AND battery charger last long enough then you will eventually get your money back. That is the basic conclusion of my article, so I think we are in agreement. The questions you have to ask yourself are: 1) are you willing to wait five or six years to get your payback, and 2) how confident are you that your batteries and charger both last that long?

    @Dax: Remember,near the top of the article I said those who use rechargeable batteries for environmental reasons was understandable. But the environmental costs of batteries ending up in landfills were not considered because they are irrelevant for the purpose of this article. Just as all of the costs related to driving to the store to buy the batteries, manufacturing and other ancillary costs were not considered. Then again, even if I did, I suspect it wouldn’t change the outcome. :-)

    @Ted: Thanks for the great comments! No question NiMH LSDs are good batteries that have their advantages – but for me I don’t think its worth waiting five or six years to realize the payback. There is just to many things that an happen over that period that makes it not worth the risk for me. A couple of clarifications: I did not use the retail price for the NiMH batteries I suggested; I backed off the suggested list price by approximately 20%. Also, the 18-month period for the wireless mouse is simply the amount of time I have owned my wireless mouse. Of course, the longer you own your rechargeable batteries, the more cost effective it becomes – which is what I said in my article.

  24. 30

    Michael says

    You haven’t mentioned the Kid factor yet.

    If you have kids, rechargeables gain a huge advantage. They will find your flashlights and leave them on, play their toys for hours (and then leave them on), Jam the remote under a toy (leaving it on) and generally use up batteries much more quickly than normal humans are capable of.

    Then once you’ve got the charger to take care of that, throwing a rechargeable in the wall clock isn’t as bad of a deal (you might even have an extra if the toys don’t require a multiple of 4).

    Anecdotally , we bought a NiMH charger and an assortment of rechargeable AA, AAA C and D sized batteries. The AAs are finally dying this year. They will power kids toys for a few days, but will no longer power my wife’s camera’s flash. I feel like we got our money’s worth, and am getting ready to buy new batteries come January.

  25. 32

    Layla says

    Sorry, but I see this kind of sensationalist writing as extremely short-sighted!!
    (And by this, I mean the title!!)

    There is a lot of good information in the article, but someone will just look at the title and say: ‘Hey, I don’t need to buy rechargeables!’

    You were lucky with your wireless mouse (and battery!) My cousin used up A LOT of batteries in less than one year!! Before we talked and I told them that rechargeable batteries exist! /sigh/

    Also, who plans to live just for one year? Maybe add ‘for terminally ill with cancer’ in the title?
    Everyone plans to have rechargeable batteries for a long time, and we are very happy with ours, and have had them for years!

    And those ‘environmental reasons’ are not just ‘environmental’ – we are talking about human health!!
    Have you ever lived near a landfill or incinerator? Great health risks are imposed on people living near by, toxic-laden water or air can travel far too – and throwing trash in landfills ‘because it’s short-term cheaper’ may cost *a lot* of money!!
    How much does one cancer cost? Or two?
    Those treatments are extremely expensive!!

    And if some batteries ‘don’t need special recycling’ it means they’re not AS toxic as others, ideally they would still be recycled, as the landfills are filling up and incinerators are pushed worldwide!
    Landfills are basically chemical bombs waiting to happen, often haven’t been planned well enough, fires occur due to methane and the chemical reactions in there are just unpredictable!

    I do think it’s sort of irresponsible to even just suggest people can just toss batteries instead. How difficult is it to bring them back to a store and put in a box where they can be properly recycled?

    So puh-lease! I would perhaps survive ‘Why rechargeable batteries are not always immediately cost-efective’ but from someone who advertises the blog with ‘believe in personal responsibility’ I would expect more!
    With respect, Layla.

    • 33

      Len Penzo says

      Sorry, Layla. Your proposal that I should re-title my article “Why Rechargeable Batteries are Not Always Immediately Cost-Effective” would not be responsible because it is simply not true. As I showed, there are many cases where they are simply NOT guaranteed to be cost effective. As for making this a human health issue, do you apply the same criteria for cars as you do batteries? Rather than a car, do you drive a horse and buggy? After all, automobiles spew far more toxins into the environment (via their batteries and emissions) over their lifetime than a little AA alkaline battery. No? Then puh-lease! ;-)

      I’m glad, Layla, that you have chosen to go with rechargeable batteries to save the environment and make a stand for better human health – but please don’t ask me to mislead my readers simply to push your particular agenda.

  26. 34

    Steven Kellett says

    Your argument about cordless mouse batteries and keyboards is flawed because most people already have acharger for their high drain devices. If you already have a charger you can take the $40 cost for the charger out of that equation. Yes most homes have a great many low drain devices but they also have a great many high drain devices. I use rechargeable for 2 cordless mice, 2 cordless keyboards, 3 transisitor radios, 3 digital cameras, bathroom scales, dozens of kids toys, 2 torches, 4 wii rmotes, wii fit balance board and the list goes on. Rechargeable batteries save me several hundred dollars per year not to mention the impact on the environment. Even if your argument is correct (and I strongly disagree that you are) some people do not mind spending more money to save on the environment. Solar panels are agood example. This is one iem that does not stack up in cost effectiveness but people prefer to use them to reduce carbon emmissions. There are only two items in the home I would not use rechargeable batteries in and they are your remote controls that are very low drain and smoke detectors. The reason you should not use them in smoke detectors is not on cost but on safety. Rechargeable batteries when they go flat have a very fast drop off in voltage compared to alkalines that drop off in voltage very slowly. What this means is that when rechargeables go flat it happens fast and if you are out when they go flat you may not hear the warning beeps to warn you the battery has gone flat.

    • 35

      Len Penzo says

      Thank you for your comments, Steven! But I have to tell you, it is your logic that is flawed. :-)

      Unless you can somehow conclusively prove it, your opening statement is anecdotal – which completely undermines your argument. And I strongly disagree with your assumption anyway; I’ll wager the vast majority of people don’t use rechargeable batteries – and therefore don’t have chargers – simply because the high up-front costs discourage their use. :-)

      Secondly, it doesn’t matter when you buy the charger. You still must use it in your analysis, if you are being honest with yourself.

      I realize the environmental benefits of using rechargeable batteries – I stated that in the opening paragraphs – but that does not make my analysis invalid from a personal finance standpoint, which is what it is. The fact that you have made a conscious decision to pay a little more money to use rechargeable batteries in low drain devices to help the environment is noble. It’s just not the best decision from a personal finance perspective.

  27. 36

    Charger says

    This is a wonderful article. I must tell you, i was not aware of the kinds of batteries. This article is too knowledgeable and informative for everyone. I think using alkaline batteries and rechargeable batteries intelligently, as explained by you is going to be really cost effective for all.

  28. 38

    Nikon says

    I just couldnt leave your website before saying that I really enjoyed the quality information you offer to your visitors… Will be back often to check up on new stuff you post!

  29. 39

    Ian says

    “if those batteries are warm to the touch when charging you really should find a better charger”
    I have never seen such a charger – ALL the high quality smart chargers I have seen (Maha, Varta etc) heat the batteries – cheap chargers are just slower and actually heat the batteries LESS because of this.

    As has been pointed out nearly all NiMH batteries are low drain now so bang goes your low drain argument.

    The relative cost of NiMH to Alkaline batteries where I live is about 3:1. I only have to get 4 charges to save money. Not a very long payback.
    my remotesx6, camerasx3, mouse, keyboard 2x childrens MP3 players (these would use 1 Alkaline/per day) countless kids toys etc.
    Obviously the cost of a charger spread over all these is minimal.

    quote”Unless you can somehow conclusively prove it, your opening statement is anecdotal ”

    Ummm, can you prove ANY of what your article says?
    Are you REALLY an engineer? If so I suggest you do a bit more research before you make a fool of yourself

    • 40

      Len Penzo says

      Well, there you have it, Ian. Speaking of anecdotal arguments, you just made another one – that is, you haven’t seen such a charger so it must not be true. ;-) Seriously, there are plenty of cheap chargers with rapid charge cycles out there that cause the batteries to heat up.

      You conveniently leave out the cost of the charger in your payback calculation. I already noted that alkalines make sense for high-drain devices.

      And yes, you can conclusively prove what I am saying! There is test data all over the web, including a couple links I included in replies to other commenters.

      (PS – There was no need to make this personal, by the way.)

  30. 41

    Robby Grossman says

    If you’re talking about 4-packs of Duracell rechargeables for $15 at Best Buy, you have a point. But if you’re willing to buy a third party brand in bulk on eBay, you can do very well. A couple years ago I got 80 AAs for $110. I split ‘em with my folks and have been happy with them. Definitely saved money over the 2.5 years I’ve had ‘em.

  31. 42

    Ian says

    Ok, so to summarise:
    1. The payback time of rechargable batteries is too long (how much, why, how long – it doesn’t matter, Len says so)

    2. Most devices in peoples homes are low drain (“”””Len says so)

    3. Despite the fact they are low drain and use very few batteries, most of the batteries you will use will be in low drain devices (ummmm???)

    4. It’s uneconomic to buy a charger, they are just too expensive.

    5. However, it makes good sense to go out and buy bulk alkaline batteries… for the ..low drain devices that use almost…. no batteries?????

    6. High quality NiMH battery chargers only slightly warm NiMH batteries, if they get any hotter It’ll ruin them(those 10 year old 1600mAh Powerex NiMH which get scalding hot in my crappy MH-C20F Maha charger are a figment of my imagination)

    7. Please everyone, go to your cordless phone and hurl those useless NiMH batteries out the window – NOW.

    • 43

      Len Penzo says

      1. There is no set answer, Ian. As I explained to a less, um, emotional reader, my payback period was 6 years. Notice I said “MY” period. Everybody’s paybacks will depend on their own circumstances. I also gave an example of the payback when it came to my wireless mice and keyboards. And the article says “rarely” cost effective – not “never.”
      2. I said in a “typical” home. I stand by that statement, Ian.
      3. Don’t you think? If, say 90% of the batteries in a home are low-drain, doesn’t common sense dictate that most of the batteries you use would be in low-drain devices? Ummmm? Of course, there may be instances where you have a Wii, for example, where the number of batteries used there WOULD overwhelm the number of other batts used on low-drain devices. That’s how it is in my home – and guess what? As I stated in the article – I use rechargeable batteries for them! You seem to have missed that major point.
      4. That is often the case, Ian. Everyone has to run their own numbers.
      5. Of course it makes economical sense to buy them in bulk – depending on how many low-drain devices many homes will still need to make quite a few replacements.
      6. High-quality chargers do no harm to rechargeables. What’s your point? On second thought, never mind. I think your batteries are starting to overheat.
      7. Wow. You are getting way too emotional on this subject, Ian. :-) LOL

      Thanks for airing your opinions.

  32. 44

    Teresa says

    I have several Energizer NIMH rechargeable batteries that have not been used in some time. They are maybe 2 years old, used rarely, and never left in devices (always removed). I recently bought a new camera that can take AA batteries. I plugged in 3 batteries in the 4-slot Energizer recharger. Two charged, the third did not. They were not removed until the green light indicator came on. The 2 that charged showed a “good charge” on my battery tester. I put them in the camera and it showed low battery and would not operate. I took them back out to retest them and it still showed “good charge” on both of them. Plus, I have read to remove rechargeable batteries from the recharger when done. So, a person is expected to know how many hours it takes for a battery to recharge? And, make sure they are home to remove them? And, how do you know if you should replace a rechargeable battery? How do I know if it is my camera’s problem or the batteries? The battery for this camera is $10 if I buy the camera battery. I just bought some Energizer Ultimate Lithiums to try in it. I had so hoped the rechargeable ones would work.

    Thank you, Teresa :)

  33. 45

    Jamie says

    I understand your point of view, but generally disagree. More and more, households are purchasing items which have moderate-high drain: digital cameras(ESPECIALLY with flash); game console controllers(many times 2x AA alkalines will only last a moderate gamer days rather than weeks or months); portable DVD players; MP3 players; etc etc etc. I’d be willing to admit that rechargeable batteries are not financially the best option for everybody. In a rapidly increasing number of cases though, I think the financial viability of using rechargeable batteries is there.

    There is also the convenience factor. You say its more convenient to buy a whole whack of batteries in bulk, but really, how many people ACTUALLY do that? Almost everyone I know who is still stuck on alkalines buys a pack of 4 or 8 when one of their devices runs out, then is back in the store a month later buying another pack to replace other batteries.

  34. 46

    Jeff says

    I’m in agreement with many of the arguments regarding disposable batteries, but find alkaline manganese zinc batteries the poorest choice among disposables. I would not find button cell rechargeables useful at all with the much higher capacity and high quality lithium and silver oxide cells available. I use disposable lithium transistor batteries in my smoke detectors because they don’t seem to leak. I won’t use any Duracell products because they have leaked on me more than any other brand. Putting a set of Duracells into an expensive LED flashlight and then ruining the device because of leakage is hardly cost effective. They do warranty the battery against leakage, but it is quite inconvenient and even then they will try to get out of repairing the item stating that the batteries were stored inappropriately in the device. I grew tired of ruining my lights and my remotes with disposable alkaline cells. The cost of purchasing my AccuPower LSD AAA, AA, C, and D cells was more than worth it just for this reason alone. I stick them in my flashlights and remotes and don’t worry about leakage. I simply recharge the cells once a year. I would never trust my Logitech Harmony remote to any alkaline cell. It’s just too expensive to trust to a cell with tendencies to leak.

  35. 47

    Barbara Friedberg says

    Len, THANK YOU FOR REMOVING ANOTHER THING TO FEEL GUILTY ABOUT!! I’m not going to analyze anything you said but just take it at FACE VALUE and save myself some time!! Every time I buy new batteries I feel guilty for not having a whole set up for rechargable ones! As of NOW, I’m going to drop that guilt trip!!
    .-= Barbara Friedberg´s last blog ..50 Habits to Increase Wealth =-.

  36. 49

    Catalina Strech says

    Your post is a breath of fresh air compared to the usual rubbish I learn on solar power. There’s a lot of scams available. Thank you for helping me out.

  37. 50

    Harvey Flea says

    Wow, how emotional people get debating the pros and cons of batteries! I actually ran across this site looking for info on charging batteries from the sun. Let me tell you, halfway through a solar project (after the solar panel, charge controller, and inverter was purchased), solar power is NOT a way to save money short term. It’s expensive. But if it saves some money in the long run, great. Either way, it gives me the peace of mind of knowing that even if the power fails again, I can charge my laptop, cell phone, etc. I look at rechargable batteries the same way. Not a perfect solution, perhaps, but something to fall back on if I’m out of fresh batteries. And it’s fun. You won’t save money with either solar or rechargables, but it’s fun.
    .-= Harvey Flea´s last blog ..Yuri Tackles Tax Time =-.

  38. 53

    Jason West says

    I agree with you, Rechargeable Batteries are not always cost effective. That is the reason I never use these batteries in my wall clock and alarm clock. You have mentioned useful recommendations here on using rechargeable batteries wisely to be benefited.

  39. 54

    Bill in NC says

    So, no kids?

    Most of their toys would be classified as high-drain devices.

    Rechargeable LSD NiMH AAs are cost-effective for those.

    And even eneloops only cost $2 on sale.

      • 56

        Bill in NC says


        let me recommend the lithium AA for those applications that are critical (grab some battery size adapters and never have to purchase C cells again)

        I had too many alkaline batteries leak even when stored in conditioned space – lost many flashlights that way before switching to lithium AAs (about $1.25 delivered via ebay) for critical stuff like emergency flashlight/radio

  40. 57

    Darin in MN says

    Len, When I first saw the title, I thought this was an article from 2004. While I agree on the whole “low draw” wall clock argument, in this day and age, no one is concerned with those types of devices in our homes. Throw some alkalines in them, and move on. Problem solved. Now… on to everything else in my house that I’m constantly scrambling to find batteries for, month after month – that are constantly eating up batteries. To make the claim – Why Rechargeable Batteries are “rarely” Cost effective… are you kidding me?
    99% of everything in my house that truly counts are high draw devices (cameras, toys, video game controllers). Any akaline batteries I’ve ever bought in bulk have been quickly used up in these types of devices. And about the added up front cost…I bought a Rayovac charger and rechargeable batteries over 8 years ago that I’m still using today for most of these applications. This doesn’t even take into account the new Hybrid technology that is superior to my rechargeable batteries. To sum up, I don’t disagree so much with a very few of your specific points…it’s the title of your report that I personally find ridiculous. Talk to anyone with kids, and bring up “batteries” – trust me, they’re not worried about their clocks and thermostat. I think a more fitting title in my opinion would be “The few instances when rechargeable batteries are less cost effective than alkaline.

    • 58

      Len Penzo says

      Thanks for chiming in, Darin. (No pun intended. Well, okay, yes it was.) LOL I would be careful assuming “no one” is concerned with low draw devices in our homes. Clearly, the guy ahead of me in line who was replacing every single alkaline battery in his home was. :-)

      I also wouldn’t assume that 99% of electronics in everybody’s homes are high drain devices because that’s how it is in your home. Let’s look at common low drain devices:

      1) Remote controls
      2) Clocks
      3) Smoke alarms
      4) Flashlights
      5) Radios

      By comparison, lets look at some common, and not so common, high drain devices:

      1) Cameras
      2) Portable Disc Players
      3) Hand-held Games
      4) Remote control toys
      5) Game console remotes (wii’s)
      6) Boom boxes
      7) Hand held TVs

      Maybe I am all wet on this, but I’ll argue that the majority of all homes have most or all of the items in the first list (low drain devices). Not so for the second list (high drain items) – especially for homes where the average age is over 50 and/or there are no kids in the home.

      • 59

        Matt says

        I beg to differ about flashlights being low drain. This is especially true if we are talking about ANY flashlight that runs on AA batteries. Remember that even 500ma is pushing the limit of what is feasible for any period of time from an alkaline.

      • 60

        BC says

        I’ve used NiMH cells for certain flashlights. The output isn’t as high, but the nice thing is that one can charge overnight before needing them. The issue I have with alkalines is that maybe I put in a fresh set of batteries in an LED headlamp before going on a camping trip, but do I really need to when there’s decent charge left in the old cells.

        My solution is that I actually use both. I’ve already got several chargers, which is a sunk cost. I have a digital camera and even some reasonably low drain devices. I always use alkalines in my basic remotes and they tend to last two to three years.

        I’ve got a wireless mouse at work and one at home. I swap out a single rechargeable AA maybe once a week. Maybe I could keep an alkaline in there for a while, but I sort of like knowing I have a battery there that should last to the end of the week rather than trying to get out as much from an alkaline as possible and wondering when it will cut out.

        The ability to top off what you need overnight really helps in a lot of applications. In an application where you need enough energy for a day/week and you can just top it off at the end of the day, alkalines introduce a bit of uncertainty because there’s something left in there, but how much? Many police flashlights are purpose-built rechargeables. When they return to the station they charge them up. Maybe with something using alkalines they can get 4/5/6 days or maybe up to a week. But then there’s a bit of uncertainty in whether or not you’re at the point where you should junk the disposables either because they could stop working at any time or the output has gotten too low. Sometimes it’s better to start the day with a freshly charged set of batteries.

  41. 61

    JLD says

    Waw, amazing blog. And still going on…

    I live in Europe and I was looking for a few sets of LSD batterys when I found this article.

    I have been using cheap rechargeable batteries at about 3$ for a set of 4 NiMH AA’s 2400 mAh for more than 5 years. At this time they are so cheap it is as cheap as a set of Alcalines. 1:1.

    The only drawback is the self discharge and this is why I do use Alcalines in remotes and clocks. But that’s about it.

    The new LSD batteries are more expensive, but there is no drawback. Up to anyone to consider if it is worth it, but for all uses but remotes, thermostats, clocks and perhaps low-cost LED lamps, a rechargeable battery is more cost effective.

    Yes, I have more low draining devices but that is why they don’t need as much batteries. If you have 5 remotes, you probably need about 10 alcalines every two years. If you have one digital camera running on AA’s, you would probably need two AA’s every month, which is much more even this is only one high drain device.

    So the artickle is somehow misleading !

  42. 63

    Brad PCT says

    Hi, I work for a company called PC Treasures, and we offer a charger that I think is very cost effective. It’s called the ReZap Battery Engineer. Check it out at digitaltreasures.com.

  43. 64

    Kurt Woloch says

    I see the payback time a bit differently. I agree with you that if you’ve only got low-drain devices in your household that don’t consume much batteries, buying a charger and rechargable batteries probably won’t pay off. But if you’ve got just one high-drain device which for itself alone justifies the purchase of a charger and rechargeable batteries of it, then the charger is already paid for by itself, and additional rechargeable batteries (at least of sizes you can now charge with that charger) only have to pay for themselves and not the charger. At that point, I’ll guess that the cut-off point would be about a one-year battery life, so non-applications for rechargeable batteries for me would be wall clocks and most remote controls, which typically take longer than a year to use up their battery. I admit that this length of time used to be shorter before LSD batteries came about simply because of the inconvenience to have to charge them rather often because they discharge themselves so rapidly.

    I also agree with the “kids” point of other readers. I can remember I consumed heaps of batteries when I was 10 years old, but later the demand dropped off.

    I also think the price comparison is a bit off. Here in Vienna (Europe), name brands of AA alkaline batteries sell for about 5 Euros a 4-pack while you can get NiMh AA cells for between 12 and 20 Euros a pack. Discount AA alkalines go for 99 cents through 1.39 Euros for a 4-pack, but discount stores also from time to time have NiMh batteries on sale for about 3,50 through 4 Euros a 4-pack, and the last ones they sold also were of the LSD type. So in any case, the price factor for me would be about 1:3 to 1:4.

    And with buying alkaline batteries in bulk I see one problem – leakage. It depends on how many batteries you actually need, but if you buy 30 of ‘em and it takes a few years until you have applied all of them, the last ones you apply may only have a short time before they leak… maybe still while they’re being used. Therefore I’d avoid buying too many alkaline batteries in advance. The same holds true for rechargeables, however… they also leak if not in use, and they also age with time, although I’m still using some 9V rechargeables which are about 20 years old and still running fine, and I’m just testing some old sets of AA NiCd cells which are also 15-20 years old and still seem to hold their charge at full capacity.

    • 65

      Len Penzo says

      Thanks for your comments. You make some good points. As I have already mentioned, I do use rechargeable batteries for the kids Wii remote controls. Those are very high-drain devices and it would be ludicrous to NOT use rechargeables.

  44. 66

    Jim says

    Good, well written article. I love the way you are questioning a trend. However, I disagree with the overall assessment. Low and medium draw devices may make up the majority of gadgets in some homes numerically, but they do not make up the majority of the battery spend, for the obvious reason that they draw less charge.

    A wall clock might need 1 new battery every 5 years. What sort of battery goes in there – alkaline or hybrid rechargeable – doesn’t matter because the ongoing cost is insignificant anyway.

    Your fellow shopper will save significantly by putting hybrids into flashlights, radios, toys, FM transmitters, etc. The fact that powering his wall clock with hybrids will be of marginal bebefit does not undo the savings he makes with higher draw devices.

    I disagree with your assessment that rechargeables should not be used in wireless mice, because it is based on an assumption that the charger and multiple battery sets must be bought just for the mouse (+keyboard). In reality, you would have just one charger for all rechargeables in the household, so the cost would be offset by savings made with the higher draw devices. Clearly, nobody would by a whole range of rechargeable kit for just a wireless mouse.

    The article makes no mention of hybrid rechargeable batteries aka “LSD” or low self discharge (eneloop, hybrio etc). I assume this is what your fellow shopper was buying. They hold charge and so can be used, even for emergency flashlights. If the article is talking exclusively about the old fashioned rechargeables that discharge quickly when left unused, well then I would agree with pretty much every point.

  45. 67

    saxa says

    all the batteries denoted “pre-charged” are the only nimh long hold time type to get. eneloop is just sanyo s version……

  46. 68

    David says

    Another, seemingly annoying inconvenience of NiCD or NiMH batteries are the voltage, being 1.2 volts, compared to Carbon-Zinc (Heavy Duty) or Alkaline’s 1.5 volts. However, Nickel-Zinc (Ni-Zn) provides 1.6 to 1.8 volts!!!!!! :)

    • 69

      Matt says

      But that all changes when you start drawing a decent current from the battery (say, .5A-1.0A). Those 1.5V alkalines and heavy duty batteries suddenly become 1.0=1.1V batteries! However, under the same load, NiMH and Nicad batteries hold steady at around 1.2V! Also, while the voltage of alkaline and heavy duty batteries drops with use, it stays quite steady at 1.2V with NiMH and Nicad batteries. In other words, even though the nominal voltage of disposable batteries may be higher, the voltage under a load will be lower for all but the lightest loads on the freshest batteries.

  47. 70

    David says

    Also, Lithium-ion batteries aren’t that toxic, if they are at all. They actually DON’T contain the toxic metal lithium, but I really don’t know why they have lithium in the name.

  48. 71

    jack bradbury says

    Wow………….interesting little thread. Len, you have a point on some appliances, but in general, and that’s what your title is, rechargeables ARE cost effective. I grant you, if you take an instance where someone buys a charger and batteries to power one device, it would take some time to recoup the cost. But Len, let’s face it, people would be powering numerous items so the chargers cost would not be ascribed to one item. Play fair! I think the sensationalistic headline is what gets peoples hackles up.

    • 72

      Len Penzo says

      I don’t follow your logic; how does the number of devices work into the equation? It’s based on the number of recharges, independent of what your recharging.

  49. 75

    V J says

    I’m not sure of the age of these postings, so I am curious if the current technology and cost effects your opinion. The Sanyo (SECHR3U8BPN)1500 Eneloop NiMH AA 1900mAh are pre charged and retain 75% of that pre-charge after 3 years. In a 8 pack they are currently < $2.50. You can get a 4 pack (SECHR3UTGA4BP) with a nice Eneloop quality slow charger for < $15. Assuming the batteries are valued at $2.50, then the charger cost is < $5.00.
    Also I've read that 1.5V alkaline typically discharge at 1.1V to 1.3V as compared to the 1.2V discharge of rechargeables.
    Thanks for discussion.

  50. 77

    Dewey 1693 says

    I understand the new 1500 Eneloop are slow discharge equally well suited for clocks, remote controls, flashlights, radios, smoke alarms, etc.
    If I only got 15 recharges instead of 1500 that would make them much much better than the alkaline technology based on cost along.
    I also like that they are always ready for use just like an alkaline right out of the blister pack.
    Just looks like folks need to be sure to get the current 1500 Eneloop and NOT the 1000 Eneloop.
    Pretty much right in your opinion?

  51. 78

    Jonathan Wingate says

    Freaking awesome, things like this make me turn on my Wii and play Brawl again. Downloaded, for sure.

  52. 79

    Tex Hunter says

    I like to know where you buy alkaline batteries for 30-40 cents each. Us pedestrians here buy them cheapest like at Walmart, where a pack of 8 cost about 5 bucks. That is about 62 and a half cents.

    • 80

      Len Penzo says

      Costco. Even though this post is now two years old, the prices still hold.

      For example, as of January 28, 2011, Costco was selling alkalines for the following prices:

      Kirkland Alkaline AAA: 48 for $17.43 (36 cents each)
      Kirkland Alkaline AA: 48 for $12.20 (25 cents each)
      Duracell Alkaline AA: 40 for $16.27 (40 cents each)

      Hope that helps, Tex.

  53. 81

    EF5Twister says

    Many thanks for this comprehensive post. You covered the waterfront and the number and length of the responses shows how much it was appreciated.

    There is such misinformation out there about battery charging characteristics and a lot of it I feel is perpetuated by the manufacturers.

  54. 82

    One Way Link Building says

    I agree with with whole article. I use expensive charger and quality NiMH batteries for years. My little camera “eat” batteries and once I put cost on paper and came out that is reasonable saving with rechargeable ones. And it is one of examples.

  55. 83

    Conservationist says

    I don’t agree AT ALL that rechargeable batteries are environmentally better (or at least, that we can take it for granted). We are NOT running out of landfill space (this is an outrageous myth), and we NEVER will. Also, modern landfills (although fewer in number) are larger, high tech and well sealed (i.e. they do not “leak”), engineers have fixed that problem.

    Further, nobody is considering the cost of production and environmental impact of manufacturing. If it’s ten times cheaper and efficient to produce one type of battery, that means less energy used, fewer resources used, and so on. Usually mass production makes a product much, much cheaper (and environmentally friendly) to produce.

    You can’t just assume that rechargeable batteries are better for the environment without understanding all the facts and considering the entire production and life cycle of the products.

    For more info google something like “recycling myth”, particuarly good are some of the articles at mises.com (economics site).

  56. 84

    Cedric says

    I find it ironic that, while our household doesn’t buy rechargeable batteries, we use them in our wireless telephones and iPad. Our experiences with the cheap rechargables were pretty bad. We didn’t like finding out that the batteries we bought couldn’t be used with our digital cameras because their mAh was too low. Thanks to the manufacturers for thinking ahead and putting in rechargable batteries in our high use items for us!

  57. 85

    Matt says

    One VERY important factor that you have not considered in the debate of NiMH vs alkaline batteries is actually the psychological factor. You see, regardless of how cheaply you may be able to buy bulk alkalines at a big box store, they are ALWAYS going to be looked at as a ‘limited resource’. When they run out (and they always do ALOT faster than you think they will!), you will have to buy more. That requires spending money, making a trip to the store, and having to remember to get them when you are there (and forgetting is actually quite easy when you have more important things in your life than batteries). This tends to drive people into conservation mode. Simply put, disposable batteries are limited, cost money, and require a run to the store to get them. So you better not waste them! You need to make them last!

    Rechargeables change the whole equation quite a bit. Sure, rechargeables go kaput after a while, and so do chargers. But the lifetime is generally quite long. Also, the cost of electricity to recharge them is negligible. So when you have rechargeables, you don’t think of them as a ‘scarce resource’. You no longer have to worry about wasting batteries. You can splurge when you use them. In the end, this means you will probably actually use your gadgets significantly more if you have rechargeables vs disposables.

    In the end, this not only means you will get more use out of gadgets. It also means that your rechargeable batteries become alot more cost effective (when you consider the cost of disposables at this increased use level). It also means you don’t have to yell at your kids for playing around with the flashlight and draining the batteries!

  58. 86

    Roberto says

    >But a set of eight good rechargeable AA batteries (five for the mouse and keyboard plus three spares) would set me back roughly $24. Add in the cost of the charger (a good one can run upwards of $40) and you can see that the payback period on the rechargeable batteries becomes a real issue.
    At my local supermarket I bought a Panasonic charger with 4 Panasonic “Evolta” AA NiMH for 12€ ($15.79). 4 AA or AAA Evoltas are 9€ ($11.84). That is under $28 for both.
    Are you buying gold plated batteries or what? And wich definition of good are you using for the charger? The priciest one you can find?

  59. 87

    Mark says

    One factor that you didn’t mention in your article is the problem of leaking alkalines (aka alkaleaks!) You only have to have a single alkaline leak and destroy a valuable device to completely destroy any savings that you initially made by using alkalines. Unfortunately alkalines are prone to leaking without warning, so unless you’re constantly checking your devices, there’s a good chance that you’ll find a low drain device already damaged when you go to replace the batteries. I consider using rechargeable batteries an insurance policy against this type of problem.

    As others have mentioned, Eneloops (and other low self discharge NiMH batteries) are an ideal replacement for alkalines in most devices. Although NiMH is rated for 1.2V and alkaline is rated for 1.5V, the numbers aren’t directly comparable. 1.2V is the mid point voltage that NiMH batteries deliver under load whereas alkalines only deliver around 1.5V when they’re new and not under load. Under even a relatively low drain Alkalines quickly lose their voltage and fall below the level provided by NiMH. Any device that can’t run off rechargeables is not going to be able to use the full capacity of an alkaline and is IMHO faulty by design.

    When it comes to deciding to purchase extra rechargeables for moderate to lower drain devices such as your keyboard or mouse, the cost of the charger should no longer be a consideration if you’ve already purchased it along with rechargeables for your high drain devices.

    When it comes to chargers, your evaluation of them is actually incorrect. Cheap chargers are generally dumb timer based slow chargers. Quality chargers will generally charge in 1 to 2 hours and will monitor each cell individually so that each cell is fully charged and none are overcharged. Slow timer based chargers always put a fixed amount of charge into each cell regardless of their state of charge, so if you’re wanting to top off half discharged cells, you’re effectively overcharging them with a timer based charger. Normally, the charge rate is low enough that it’s not a major problem, but it’s still not good for the cells over the long term.

    15 minute chargers are another story altogether – they really do heat up the cells and cook them. With quality cells, you’ll likely still get over 100 cycles with them, but you’re better off with a 1 to 2 hour charger and keep spares already charged and waiting. If you really want to be a miser and not pay for the cost of spares, you could buy a few alkalines to use temporarily while your rechargeables are being recharged.

    Although chargers can fail just like any other piece of electronics gear, they’re generally pretty reliable, so I don’t think that should be too much of a consideration in the grand scheme of things.

    I can assure you that if you purchase Eneloops, you won’t have any problems with them failing before they’ve paid for themselves in things like your keyboard and mouse. I have over 100 of them and in the 6 years since I started purchasing them, I haven’t had a single failure. Most of them are still performing like new. The few that I have which have been heavily used with literally hundreds of recharges each are still running with around 75% of their original capacity and are still quite useable.

    In summary: For households with only low drain devices, I agree with your assessment that sticking with alkalines generally makes sense from a financial point of view – as long as you’re not taking into consideration the problem of them leaking.

    For households which have devices that regularly go through alkalines, it definitely makes sense to invest in rechargeables. Once the charger has been purchased, I think it then makes sense to at least seriously consider rechargeables for lower drain devices as well to avoid the risk of alkalines leaking.

    • 88

      BC says

      I’ve never seen a quality NiMH (made by Sanyo or Panasonic) cell leak. I have had alkalines leak, and many ruined the devices. The worst offenders were the cheap alkalines that came with LED flashlights and Ikea batteries when they were supplied by Varta.

      The only rechargeable battery I remember leaking was one of the old Ray-O-Vac rechargeable alkalines. It died in their charger, so I called up their number and they sent me a set of batteries and a new multi-position charger (one that took up to D-cells) even though I told them it was just the charger that took AA/AAA cells.

  60. 89

    Hi(: says

    thanks for explaining to me, i am actually doing a science fair project on this, and you really helped me with your graph and explanations and stuff.

  61. 90

    Erik Nilsson says

    Your article would be more persuasive if you included at least a tiny bit of math to support your argument.

    Of course, if you’d included any math at all, you would have had to reverse your conclusions, because you’re completely, utterly wrong.

    The best rechargeable (NiMH) AA batteries money can buy cost about $3 each, or less than twice what a typical non-rechargeable (alkaline) AA battery costs. But that rechargeable battery can be used 1800 times before it wears out. Sure, your kids will lose it first, but that’s the point: you just bought the battery equivalent of a screwdriver: it’s a tool, not a consumable, and a cheap tool at that.

    As you note, in a low-current application like a wall clock, the NiMH lasts about as long as the alkaline. Well, that used to be true. Actually, in very low current applications like wall thermostats, ultra low self-discharge NiMH batteries can last 2 or 3 years between charges, while alkaline batteries usually last about a year. So, the advantage still goes to the best NiMH batteries now.

    But in a high-current application, the NiMH delivers much more power. Cameras and camera flashes, obviously, but also flashlights and almost all toys with a motor.

    Plus, if you leave them forgotten in a device long enough, alkalines eventually leak. NiMH batteries don’t leak. I mean they just don’t, in my experience. Even when dropped out of a moving vehicle, run over picked up and used when they should have been recycled, they stop working but they don’t leak.

    Add up all the cost of all the batteries you’ve ever brought against all the things they’ve ruined by leaking in them. If you’d been using NiMH batteries, that damage would not have happened. On that basis alone, NiMH batteries are free compared to alkaline.

    Add to that the longer life between charge/replacement, and the far lower cost per use, and it’s just laughable that there are any but a few specialized applications where alkaline batteries should even be considered. Smoke detectors are specifically designed to work with alkalines and not NiMH batteries, so you shouldn’t use NiMH batteries in smoke detectors, But Lithium batteries cost only twice as much as alkalines, last about 7 times as long, and work better anyway. So even there, alkaline batteries are obsolete.

    As for the cost of battery chargers, battery chargers are cheap and last a very long time. You assert that the capital costs of battery chargers are relevant without any data. I don’t really feel obligated to refute a baseless assertion, but a high-end charger costs no more than $30 and should last at least 10 years. If you are going to own rechargeable batteries for any application at all, then you need to have a charger of some kind. But it doesn’t take a formal accounting background to see that $30 every ten years is not an important expenditure in a house that goes through a typical number of batteries.

    If you wanted to do a back-of-the-envelope calc, try this: say you buy a 20-pack of AA batteries every other month from Walmart for $25. (Just checked the price online.) That’s $150 a year or $1500 over 10 years. If you need to have 30 AA batteries in use or available for use at time time (a very generous assumption) what are your costs using, say Eneloops?

    Batteries: ($3 x 30) $90
    Charger: $30

    Savings = $1500 – $120 = $1380. Yes, there a TVM, but it’s irrelevant because with alkalines you spend more than the $120 in the first year, so you can pick almost any cost of funds you want and NiMH is still way better.

  62. 91

    Dehatter says

    It dose not take logic at all. It takes math.
    Get your alkalines on sale at .25 each. I get my eneloops for 2.50 each. My new eneloops last 90% on average as an alkaline. My 5 year old eneloops last about 75%. My eneloops are rated for an 1800 charge life. Lets even derate that by 45% for fun and use 1000x. 1000 charges at a lowered life of 60% equals 600 akalines. 600 x .25 = $150 minimum I save for each eneloop I buy. Lets even buy a new charger for each eneloop battery I buy, and I still save at LEAST $133 PER battery. I was going through 50 AA per month with 6 kids, and have not bought an alkaline since. Not one single eneloop has failed to date, with another 5 years expected. Actual amount saved based on the 48 eneloops I purchased 5 years ago is $5600, with another $5600 min expected (as I have only charged an average 200 of my rated 1800 times). You go buy your 4000 alkalines and throw them all away. I will still be chugging away with my 48 ten year old eneloops. -shrug-

  63. 92

    Shawn says

    Isn’t your whole article anecdotal? Using personal examples you knock others for bringing up?

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