Are Rechargeable Batteries Really Cost Effective?

At my house, we use a lot of AA batteries. I did a count recently and found that there are 36 AA batteries in use around our home. Some of these are replaced frequently, like those in the Wii remotes and in my son’s self-propelled school bus toy — others are replaced rarely (less than annually), like the ones in the wall clocks. My estimate is that in an average month, we replace 10 AA batteries.

Picture: wetc1/Shutterstock

Because of our heavy battery usage–120 AAs on average in a year–we were interested in finding an alternative to this expense, and we found that an investment in good rechargeable batteries up front will save significant money over the long run. Let’s walk through this step by step. In order to do a fair cost comparison, I’m going to use prices from Amazon.com — a bargain shopper will be able to find better prices on specific items, but by using the same source, we can do a fair and valid price comparison.

Annual Cost of Non-Rechargeable AA Batteries

Since in a given year we burn through 120 AA batteries in our house, we obviously buy them in bulk in the largest packages we can. We’ve also tried many, many different brands of AA batteries and we’ve found that for our use, we almost always get the best bang for the buck from e2 Titanium batteries. They don’t have the longest life among the ones we’ve tried, but my wife and I have both observed that they have a very long life for the dollar.

So what do these batteries cost? You can get a 12-pack of e2 Titanium batteries on Amazon.com for $7.77. Since we use 120 per year, these batteries cost us $77.70 per year.

Startup Cost of Rechargeable AA Batteries

In order to effectively use rechargeables for our AA battery usage, we need to replace all 32 batteries with rechargeables, with four batteries to spare so that we can swap in fresh ones immediately and then put the empty ones on the charger. We’ll also need to invest in a charger.

After researching rechargeables, I found that almost every source recommended using eneloop rechargeable batteries because they don’t become weaker after many recharges and, more importantly, they hold their charge very well while just sitting there. I’m also investing in a quality battery charger that will last forever. Since I want these batteries to be a seamless replacement for our old AAs, I’m willing to buy the best.

As a result, I selected GE/SANYO eneloop AA batteries, which are available for $11.20 for a set of four on Amazon. Since I need 36 batteries, this is a startup cost of $100.80 for the batteries.

For the charger, I followed recommendations and selected a La Crosse BC-900, which not only charges batteries, but actually completely discharges them before beginning a charge, extending the number of recharges that you can get out of a battery significantly. Unfortunately, there’s another big cost here — $47.94. Thus, the startup cost for our rechargeable battery use is $148.74. I recognise that I could cut some corners here and reduce the cost by buying other rechargeables or a lower-end charger, but the goal is to make the transition from disposable AAs as seamless as possible.

Maintenance Cost of Rechargeable AA Batteries

I put the charger on my handy Kill-A-Watt to see how much electricity is actually used in a recharge — and I was surprised. The battery recharger ate up 0.02 kilowatt-hours per AA battery recharged. Since I would be recharging 120 AA batteries in a given year, the recharger would eat up 2.4 kilowatt-hours per year. With electricity costing $0.10 per kilowatt hour these days, that means the charging cost per year for the rechargeables is $0.24.

Comparing the Two

Let’s look at this year by year.

In the first year, we would spend $77.70 on non-rechargeables. Simultaneously, we’d spend $148.74 on startup costs for our rechargeable batteries, plus $0.24 for recharging, giving a total cost of $148.98 for the rechargeables. Ouch — after one year, the non-rechargeables are way ahead, being $71.28 cheaper.

In the second year, though, the rechargeables get their revenge. The non-rechargeables cost $77.70 again, giving us a total cost over the two years of $155.40. The rechargeables just add another $0.24 onto the pile, making for a total cost over the two years of $149.22. Thus, after two years, the rechargeables are $6.18 cheaper, even after that huge initial investment. Each year after that, the cost investment in the rechargeables is $0.24, while the non-rechargeables cost $77.70 — an annual savings of $77.44. For us over the long haul, the rechargeables are clearly a good investment over the long term.

Let’s look at it another way. In the examples I used above, the rechargeable batteries cost $2.80 each and the non-rechargeables cost $0.65 each. Beyond that, there was also the startup cost of the charger itself — I used a very high-end charger in the example. The best way to spread out that cost fairly is to divide the cost of the charger by the number of rechargeable batteries you purchase.

So, for that $47.94 charger above, my cost per battery for my 36 batteries was $1.33, giving me a total cost per battery of $4.13 per battery. At that rate, I have to charge up those batteries 7 times to match the cost of the disposable batteries. For me, that will take just about two years on average (some will be charged more often, some less, but that’s the average) — after that, this will turn into a great investment.

What’s Better For Me?

Let’s look at the numbers in general.

The more AAs you use in your home in total, the higher your rechargeable startup cost will be. This is because you’ll need to buy more high-quality rechargeables to rotate into the mix as the old ones wear out. You might want to just get rechargeables for the items you use often in order to reduce this number, but it’s really worthwhile to just get rechargeables into all of the places in your home where you use AAs.

On the other hand, the more batteries you use up each month, the quicker the startup cost will be recouped and you’ll be profiting from the investment. If you have a lot of heavy-use items that go through batteries like a child goes through candy on Halloween night, then this number is rather high and it’s worthwhile to dive into rechargeables.

The best way to determine if this is worthwhile for you is to keep track of how many AA batteries you replace over a long period — say, six months — and how many AA batteries you have in your home. The easiest way to count batteries is to buy a giant jumbo pack of the AAs and write the date of purchase on the back, then note the day you use up the last of the batteries — this will give you a good idea of how many AAs you use in an average month.

Here’s a thumbnail calculation: divide the number of batteries you waste in a given year by the number of batteries total in your home (plus a few for backup purposes). For us, that would be 120 divided by 36, or 3.3. That’s how many times you’ll recharge (or replace) an average battery in a year, and the higher it is, the more you’ll get out of a battery charger. My suggestion is that if your number is over two, look seriously at getting high quality rechargeables into rotation. If it’s more than four, you should definitely get good rechargeables in rotation.

I’m personally convinced that any household that has even a single device that uses a high quantity of batteries should look seriously into rechargeables. It takes some time to overcome that initial investment, but after that the savings is quite nice — it’s basically batteries for free.

Are Rechargeable Batteries Really Cost Effective? [The Simple Dollar]

Trent Hamm is a personal finance writer at TheSimpleDollar.com. After pulling himself out of his own financial crisis, he founded the site in late 2006 to help others through financially difficult situations; today the site has become a finance, insurance and retirement resource.


Comments

    If you want high quality but cost effective batteries go to a battery wholesale place......Australia's biggest is www.master-instruments.com.au

    and with the WA Xbox club im in if you see a certain guy he gives you even more discount :D

    Ohh I got Sanyo eneloops XX black series dirt cheap.....best AA rechargeables on the market

    Hmm. He reached the right conclusion at the end, but I think this story could have been presented a little better.

    I've collected 38 eneloop AA's and 8 AAA's with two eneloop chargers (each takes 4 batteries at a time) over the past 2.5 years at a total cost of $74-75. The AUD was stronger with the batteries were from overseas markets, maybe they're not the best chargers but Sanyo aren't going to sell you total junk, and recharging would still push it over $78/year... but this start-up cost seems needlessly high.

    Then take into account that eneloops advertise 1500+ charges while he only needs to charge each battery 7 times to justify the expense... the price becomes almost negligible assuming you can afford to buy the non-rechargeable/rechargeable batteries all at once anyway.

    The biggest inconvenience is that by having just enough batteries 'n they're all in use, you have to wait 2-14 hours (depending on chargers) before you can use them again, but that's not mentioned at all.

    Last edited 29/07/13 8:02 pm

      The article mentions that he has 32 batteries in use at any one time and has purchased 36 batteries giving a surplus of 4 batteries that will be charged and ready to swap out.

      Agree with the higher than average start up costs. It's not hard to find decent deals.

      Sanyo won't sell you total junk, but their chargers are not fantastic either. The problem with basic chargers is that you run the risk of overcharging. That will damage the battery, reducing its lifespan and capacity.

      An intelligent charger, like the La Crosse or Maha Powerex chargers, will never overcharge the battery, and can also recondition batteries, restoring some lost capacity. Plus, the intelligent chargers can charge batteries individually, rather than having to charge 2 or 4 at a time. This means they can tailor the charge to the individual battery, doing a much better job than others that have to charge 2 batteries in series. Also has the added advantage of being able to recharge batteries in devices that use an odd amount, like the Wii balance board (uses 3 AA batteries).

      If you're going to go to the expense of buying Eneloop batteries, I'd get a decent charger. The La Crosse BC-700 is pretty cheap, and does a great job. I think you can buy it from Amazon for $40-50, shipped.

    pro tip, get a solar powered garden light with a switch and some spare batteries. this way if any battery dies i always have charged ones waiting for me, and i even use the light every night

    I've used rechargeable for years. I currently use eneloop. But it's not just about the cost. It's about the millions of batteries disposed of, usually in landfill.

    Last edited 29/07/13 9:41 pm

      Exactly what I was going to say. I also recently realised how many toothbrushes people must throw in the bin and how much landfill it would take. Also they're dense plastic that isnt going to degrade that easily. If everyone in the Melbourne metro area use 4 brushes a year, then 4.25m people * 4 = 17m * 25 grams (average amount of plastic in a toothbrush) = 425,000Kg of plastic per year. I'm far from a hippy, but dayum.

        4 brushes a year?! I don't think I've bought 4 in my life!

    I have bought some energizer rechargeable before and the biggest issue is the charger is 4 batteries in 2 channels so 2 need to be charged at once. So I need to make sure they are kept in pairs and my daughters toys all seem to come with a requirement of 3.
    The link provided to Amazon says not available but I looked at the BC1000 instead from La Crosse and it has 4 channels and looks like a good charger. So that and some Sanyo batteries in AA and AAA I should be good. I may need to get some more of the adapters to go up to the larger sizes.

    Use rechargeable batteries, end of story.

    One factor you forgot about are the tons and tons of batteries being dumped into landfill
    around the world, they release gasses and can leak into ground water.
    So they are an environmental problem that Australia doesn't worry about.

    European super markets all have recycling stations for your cans, glass, plastic, carton and batteries.

    Always used rechargeable batteries they last a good 6+ years and are worth it.

    Good article but for people who's batteries are about to die this really needs a TL;DR.

    I have 2 18650's (big rechargeable batteries) and I get a solid day's use out of one and have the other as the spare. I throw one on to charge at night and the other, spare, goes into the device that is then used for the 24 hour period.

    I've had these particular, IMR, batteries for around 2 years now. Getting charged (and discharged) every second day for each. Would have cost a fortune if these were not rechargeable..

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