Today’s Wonder of the Day was inspired by Constance. Constance Wonders, “why do batteries come in different sizes and shape” Thanks for WONDERing with us, Constance!

Picture it: You and a friend are having a sleepover. You’ve built your fort out of pillows and blankets. Now, it’s time to raid the refrigerator. It’s really dark, though. You need a flashlight to navigate the dangerous path to the kitchen.

Luckily, you thought ahead. There’s a flashlight stashed in your pillowcase. With the device in hand, you creep out of the fort and slide the switch to the “on” position. But nothing happens. You’re still stuck in the dark!

You’ve just been struck by that age-old problem: dead batteries. Without those little packets of stored energy, your flashlight is nothing more than a paperweight. You’ll have to make it to the kitchen in the dark, since that’s where the spare batteries are stored.

That’s where your dilemma really gets confusing. What type of batteries do you need? That depends on your flashlight. It could take any one of several types of batteries. Does it use big “D” cells? Or perhaps it runs on smaller “AA” or “AAA” batteries? And what’s the big deal with all these letters on batteries, anyway?

A trip to the battery section of your local store will reveal a large selection of different sizes. Some of the most common types of batteries you’ll find there are “AA,” “AAA,” “C,” and “D.” A look around your home may reveal many other types of batteries, too.

All sorts of electronics, from watches to smartphones, have batteries. There’s also the automobile battery in cars and the one in the lawn mower. Some of these are tiny lithium-ion batteries that are smaller than most buttons! All in all, there are hundreds of different types of batteries.

Why do batteries come in so many sizes? And how did they get their names? Let’s take a quick look at the history of these little packages of stored energy.

As far back as 1749, Benjamin Franklin used the term “battery.” The word described the set of linked capacitors he used to conduct (pun totally intended!) his experiments with electricity. It wasn’t until the late 1800s and early 1900s, though, that batteries became popular as a power source.

How do batteries work? They turn stored chemical energy into electrical energy. And given their wide range of uses, it’s no surprise that many different sizes and types needed to be developed. Larger objects need more power. That meant larger, more powerful batteries had to be developed. As technology led to smaller and smaller versions of things, smaller, less powerful batteries were needed.

However, battery makers soon realized that some common standards would be needed. This would help avoid the need for developing a new battery for every idea that came along. In 1924, a group of people from the battery industry, along with several manufacturers and government agencies, met to make a standard system of battery sizes.

They decided to use the letters of the alphabet to designate a standard set of sizes. Thus, from the start, there were “A,” “B,” “C,” “D,” “E,” etc. batteries. This worked fine for a while, but eventually a need for even smaller batteries arose. After World War II, “AA” and “AAA” batteries were created for smaller applications.

Over time, some of the types of batteries simply died out, because they were no longer used in any products. For example, you won’t find any “B” batteries in most stores today. Some manufacturers may still make them for a very limited range of products. They did exist and were popular at one time, though!

That’s why your search for batteries could become quite complicated. We hope you find what you need while digging through the battery drawer! If not, it may be time for a trip to the store with an adult family member. They can help you learn more about the many types of batteries.

Standards: NGSS.PS3.D, CCRA.L.3, CCRA.L.6, CCRA.R.1, CCRA.R.2, CCRA.R.4, CCRA.R.10, CCRA.W.4, CCRA.SL.1

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