Are B Batteries A Thing? Here's Why You've Likely Never Seen Them

If you've ever wondered why there are no B batteries, great thinking. Alphabetically, it's a glaring omission — the lineup jumps from AAs and AAAs straight to C and D, so B's absence does feel like a glitch in the system. The truth is, B batteries did exist. And in a way, they still do. 

The confusion comes from the fact that two different battery types have shared the "B" label. One type powered old-school vacuum tube radios, while the other was a size category designated by the American National Standards Institute (ANSI). Vacuum tube B batteries became obsolete when transistor radios took over. But ANSI-standard B batteries are still around, though you won't find them at your local supermarket next to the AA and AAA packs.

This mix-up has fueled a long-standing myth that B batteries vanished because vacuum tube radios did, but that's only half the story. When people ask why there's no B battery, they're usually thinking of the ANSI-standard version, which is a different thing altogether. So, let's set the record straight: Why aren't B batteries in popular use? What are they used for? And, while we're at it, why is the battery naming system such a mess?

The simple reason ANSI-standard B batteries aren't common today is that they just didn't catch on with consumers. Although B batteries have more capacity than the A series, both deliver the same 1.5V (depending on the battery brands you buy, at least). The B is much larger at 21.5 x 60mm, and electronic manufacturers favored more compact, versatile options like AA, AAA, 9V, and rechargeable lithium-ion cells. Over time, companies designed their devices around the batteries people actually bought, reinforcing the dominance of a select few sizes. Economics, eh?

But that doesn't mean B batteries disappeared entirely. They're still produced and pack a solid punch for their size (8,350mAh, if you're wondering). But don't expect to find them in your TV remote — they're mostly used in niche industrial applications like backup power systems, remote monitoring devices, and precision instruments that require a specific form factor and steady voltage.

Interestingly, A and F batteries still exist too, just not in the way most people expect. A batteries hide inside older laptop battery packs, and you've probably seen F batteries around without realizing it. They're those big rectangular 6V batteries used in lanterns and flashlights. Meanwhile, C and D batteries stayed relevant for power-hungry devices like flashlights and toys, while AA and AAA batteries became the go-to for smaller electronics. B batteries may have never made it into the mainstream lineup, but they're not extinct. They just lost the popularity contest.

Back in the day, battery names were more about function than size. In early radios, different batteries powered different parts of the circuit — A batteries kept filaments glowing, B batteries supplied plate voltage, and C batteries controlled bias voltage. Any battery that handled plate voltage was called a "B battery," regardless of its physical dimensions. At first, they cranked out a hefty 120V, but as vacuum tubes got more efficient, they shrank to 90V, 67.5V, 45V, and even 22.5V. All B batteries.

Then came ANSI. In the 1920s, it became obvious that battery development was a chaotic free-for-all. Different manufacturers used different sizes and labels, which led to absolute confusion — especially during World War I, when the military wasted time (and patience) trying to match the right batteries to the right equipment. To fix this, the U.S. War Industries Board pushed for standardization, and ANSI responded with a simple system: A for the smallest battery sizes, followed by B, C, and D as sizes increased.

But as batteries got smaller, ANSI ran out of letters. Instead of starting over, they doubled down — literally. That's how we ended up with AA, AAA, and even AAAA. And let's be real: standardization still isn't perfect. Just look at the existence of 9V batteries and rechargeable lithium-ion cells, neither of which fit neatly into the naming system. Battery names may never make perfect sense, but at least now we know where the missing B went.