Batteries

Batteries and flashlights; flashlights and batteries. Saipan’s power grid woes make this topic timely.

When it comes to a weekend campout, even a lousy flashlight that you buy at the sari-sari store will probably get you by. But when power-out situations are chronic and not temporary, things become more demanding.

I’m not going to look at the whole gig today. Instead, I want to isolate just one small, and specific, part of the equation: the costs of battery power.

Specifically, the comparative costs of various sizes of alkaline batteries. I’m not talking about cost per battery. Any fool can see that at the checkout counter. No, I’m talking about the comparative costs, between battery sizes, of the electricity they hold. And I’m not addressing rechargeable batteries; that’s a great subject that deserves a stand-alone article someday.

But today is about the normal, everyday batteries you see in the store all the time.

As we will see, bigger batteries are a lot cheaper than smaller ones in terms of the juice they provide. This is just one part of the overall equation when it comes to buying and using battery-powered devices, but it’s still an important part. Well, it’s important to me, anyway, since I don’t like wasting money.

Anyway, here’s some data about battery juice from a website called AllAboutBatteries.com. This is based on “long life” (I don’t know the significance of that term) alkaline batteries. The bigger the number, the more juice the battery has:

• AAA-size: 1.41 Watt-hours.
• AA-size: 2.60 Watt-hours.
• C-size: 9.56 Watt-hours.
• D-size: 20.83 Watt-hours.

That’s quite a large range. If you crunch the numbers, you’ll see that a D-size battery holds about 15 times as much juice as the AAA-size does. Heck, the even the AA-size holds 84 percent more than the AAA-size.

As you’ll notice at the store, there are, of course, different formulations of batteries, of which alkaline, and the far cheaper carbon-zinc, are common. For any of the sizes mentioned above, carbon-zinc has only about 25 percent of the juice of the alkaline, so I’ve never seen the attraction of taking the low road here. Costs notwithstanding, I don’t want to change batteries at 3am when it’s time to find the bathroom but the flashlight won’t wake up.

Ah, costs. I’ve mentioned the raw amount of juice that the batteries provide. The next step is to consider battery prices so we can compare batteries between sizes. Battery costs are a big deal in my household. We do a lot of camping and traveling. We use a lot of batteries. Batteries are sufficiently expensive that they’re on our household “think ahead” list for shopping.

Battery costs vary widely by store, so, instead of playing that game, I’ll simply approach costs via a big-box retailer’s website. That retailer is Costco (remember them?); they sell a lot of batteries, so they are a good baseline for broad data. I’m not saying that Costco prices apply to Saipan, but it’s the comparative costs between battery sizes that I’m after. So I’ll just make some ratios here, and I’ll assume that they apply, more or less, to the world at large.

Using AAA-, AA-, and D-sized batteries from Duracell as a basis (I didn’t see data for the C-sized), this fact is easy to see: The bigger the battery, the cheaper the juice.

Here are the ratios, based on blending Costco battery costs with AllAboutBatteries.com Watt-hours information:

• AAA-size: 6.7 times D-size cost per Watt-hour.
• AA-size: 2.8 times D-size cost per Watt-hour.
• C-size: No data.
• D-size: 1.0 times D-size costs per Watt-hour. (Well, duh.)

That’s a dramatically wide range of costs between battery sizes, and this is amplified by the fact that the data at hand has an AAA-battery actually costing more than an AA-battery. Maybe the big-box, buy-in-volume situation skews things at this end of the market. But I won’t worry about it, since the magnitude of differences is so large that splitting hairs won’t change anything.

Anyway, we can see that the small profile of small batteries carries a hefty cost premium. Of course, in some cases, miniaturization is so important that it is worth the premium. For example, it’s pretty hard to imagine a remote control powered by D-sized batteries.

On the other hand, I think that a lot of equipment on the market doesn’t take into account the ultimate costs of the batteries that the user will have to bear. I keep this in mind when I’m shopping for battery-powered stuff, and that’s pretty much the entire point of today’s screed.