The most common batteries you encounter are AA, AAA, C and D. Why are there no B size batteries?
This Is Why You Never See B Batteries
It’s hard to forget the classifications of the most common batteries. Unless you need a 9-volt for your smoke alarm or those round, flat ones for your key fob, batteries often use the letters A, C and D. Why are there no B size batteries? Did they ever make them? The answers are surprisingly layered, touching on history, design standards and shifting consumer needs.
Reader’s Digest explores the history of everyday household batteries, and why you never see B batteries anymore. Ahead, learn why B batteries once had a place in early electronics, but eventually fell out of favor.
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Did they ever make B batteries?
They did!
But before we get to what happened to them, here’s a quick history: The first portable dry cell batteries were invented in the late 1800s, but by World War I it became apparent that there needed to be a way to standardize sizes and performance criteria. Battery manufacturers, government agencies and the War Industries Board developed criteria and presented their recommendations to the National Bureau of Standards (today’s National Institute of Standards and Technology, or NIST).
In 1924, a uniform size classification system based on ascending letters of the alphabet was introduced, with A being the smallest—and yes, B batteries were included. The largest battery, called a No. 6, was grandfathered into the classification system due to its popularity at the time. The criteria was officially published in 1928, and expanded in 1934. Smaller AA and AAA batteries had been in use since the early 1900s, but not standardized until World War II and later.
Why are there no B size batteries now?
So what happened in the nearly 100 years since B batteries were standardized by NIST’s predecessor? Basically, they just stopped being needed. And when you understand what they were used for, it will all make sense.
According to the American National Standards Institute (ANSI), B batteries were primarily used in vacuum tubes, which were electrical components in radios and early TVs. As radios became portable, B batteries were used as a compact power source for the vacuum tube. (The much larger TVs used power from a wall outlet.)
By the 1950s, transistors started replacing vacuum tubes and B batteries became less common. Soon, transistor radios started using 9-volt batteries, which are still sometimes called “transistor batteries” by hobbyists. Technology tends to skew smaller as time goes by, especially in personal electronics, so the need for a mid-size battery like B just doesn’t exist anymore.
Today, unless you’re buying them on eBay or at a garage sale or vintage electronics store, you won’t find B batteries anywhere. According to an ANSI standards committee report from 2002, the B battery has “disappeared altogether.”
Sources:
- ANSI: “American National Standards Institute Accredited Standards Committee C18 on Portable Cells and Batteries”
- Mental Floss: “Why Aren’t There B Batteries?”
- Ultralife: “
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