Battery Names

Stupid Question ™
Jan. 14, 1999
By John Ruch
© 1999

Q: Why are there AAA, AA, C and D batteries, but no A or B batteries? And what about 9-volts?
—Pete Johantgen


A: “If your reader is looking for intelligence in the system, there is none,” says Eveready’s Terry Telzrow, who’s spent the past 15 years chairing committees that want a better way of naming batteries.

The letter system appears to originate in the two types of early radio batteries: A (low-voltage) and B (high-voltage). The first attempt to standardize various manufacturers’ battery names came during World War I, and standards were published in 1919 by the Department of Commerce. What exactly those standards were, I haven’t been able to determine.

In any case, the letter system was universal by the 1940s, and maintained by the American National Standards Institute (ANSI). The letters indicate the size, in height and width, of the battery. For example, “AA” means “50.5mm x 14.5mm.”

The letters originally began with A and progressed upward in size. But in the 1950s, electronic equipment miniaturized, and suddenly AA, AAA and AAAA battery sizes were required. Current ANSI specs list sizes from AAAA through G, plus J, N, O and R.

Some sizes, like A, have fallen out of use. (B is still used for bicycle lights in the UK.) Others, like F and G, are always linked together in multi-cell packages for electric fences, lanterns, etc. and are never seen individually by consumers.

The N is actually smaller than AAAA—it’s called N because it was the first mercury battery, and N is the International Electrotechnical Committee symbol for that metal. The J was designed and named by Kodak specifically for its cameras.

Another problem is that new batteries often must be designed to fit inside new products. As a result, there are now about 300 sizes of battery on the market—12 times the available letters. So there are batteries known as “sub-Cs” and “two-thirds As.”

(Nobody knows why the 9-volt, which appeared in the ’40s to fit transistor radios—isn’t lettered. But its different shape, configuration and voltage probably made it recognizable enough on its own.)

The letter system is obviously insane and is in fact used only in the US and only for common household batteries. Manufacturers, other countries and ANSI itself use true (though very complicated) nomenclatures that usually indicate a battery’s chemistry, shape and dimensions.

But they don’t all use the same nomenclature. So, depending on where you are and who you’re talking to, the good old AA battery could be an E91, MN1500, 815, KAA, AM3, 15A, LR6 or SUM1.

Even if a universal system was adopted, battery manufacturers worry that American consumers would be confused without the memorable letters A, C and D. (Duracell is even promoting the use of the letters in Europe.)

But Telzrow said consumers are the ones who’d benefit the most from a simplified system. “I stood in the airport in Frankfurt, Germany watching an American trying to buy a ‘AA’ battery,” he said, knowing she really needed an LR6. “They weren’t our brand, or I would’ve helped her buy one.”