3 min read

What Cast Iron Pans and Batteries Have in Common

Do you know how to charge your electronics? When I was a teenager, the standard advice was to never leave your computer (or phone) plugged in for extended periods of time. Articles were plastered all over the web telling people to stop leaving phones and computers charging all the time (that means you, Mom!). Much better to have the battery mostly drained, then charge it back up again.

But then, things changed. Battery technology and charge monitoring technology got more sophisticated, at least in many devices. So now, you can leave your electronics plugged in with no ill effects.

Or maybe it’s still bad for your batteries? Honestly, I’m not so sure myself. There are multiple generations of advice articles, still on the internet, arguing against or in favor of leaving electronics plugged in. And there are different battery technologies that can impact this basic advice. You have to check the article publication date (which, in some cases, may not be accurate) to see whether this advice should apply.

The upshot is that a lot of people are confused about what they should do. And they are confused largely because battery technology is complicated. The slew of articles advising people about charging focus on the correct behavior (letting batteries drain or not; leaving electronics plugged in most of the time or not), rather than on the conceptual details of battery technology that lead to the correct behavior for preserving battery life. I’m not suggesting that everyone become amateur batter engineers. But the problem of continuing a behavior that is no longer relevant because the underlying circumstances have changed occurs because we are largely ignorant of those underlying circumstances.

How about taking care of cast iron pans? My brother was the first in the family to go ga-ga over cast iron, about 20 years ago, and he told me you should never use soap on the pan because it would take off the seasoning. Several years later, we learned this was a common myth. Scrubbing with soap will not take the layer of oil seasoned on the pan. The thing is, this wasn’t always a myth.

In the old days, when many people used cast iron pans, soap was often made with lye – a chemical that could corrode the seasoning on your cast iron pan. I don’t know how many people at that time knew that it was the lye (and not the soap itself) that was the important ingredient, but for generations afterwards, parents would teach their children that you shouldn’t use soap when washing cast iron, even when soap-makers stopped using lye. Like with battery charging, the underlying context changed, negating the benefits of the behavior. And, because the advice was at the behavioral level (and not the conceptual one), people continue to believe that using soap will ruin a cast iron pan.

But there’s a more important way that these cases are similar. I have written elsewhere how business interests or political lobbying or media misrepresentations or lack of scientific literacy lead to the poor use of scientific knowledge and the spread of misinformation. But there is not a big bad battery lobby intent on having everyone ruin their batteries, like the oil and gas companies have been intent on combating efforts to mitigate climate change. There were no cast iron cronies expertly manipulating public opinion so that everyone could mistreat their cast iron pans, like how cigarette companies expertly cast doubt on the evidence that smoking causes cancer.

Au contraire. Advice on proper battery care is often provided in instructions with the batteries or the electronics. It’s also readily available on the internet for specific products. Companies who sell cast iron pans try their darnedest to teach people how to use them properly. The spread of misinformation is a normal feature of human societies, even in the absence of opposition research, disinformation campaigns, media hyperbole, and “bad actors”.


If you want to read more about oil companies and cigarette companies misleading the public on science, check out:

Oreskes, N., & Conway, E. M. (2011). Merchants of doubt: How a handful of scientists obscured the truth on issues from tobacco smoke to global warming. Bloomsbury Publishing USA.