In Japan, battery sizes don't follow the battery size name conventions you might be used to if you come from an English speaking country.
Japan Battery Sizing System
In English speaking countries, the common batteries sizes start with the smallest common size named triple A or AAA and go up through the alphabet in a way that, if you didn't know it already, would make no sense.
The Japanese system ranks battery sizes by number rather than alphabet and starts with the biggest common battery size and go up in number as the size decreases, which also seems counter-intuitive but once you understand, makes a little more sense than the English speaking system.
Japan-English Battery Size Translations
|English Size||Japanese Size|
|Triple A or AAA||tan yon (たんよん) or 単4|
|Double A or AA||tan san (たんさん) or 単3|
|C||tan ni (たんに) or 単2|
|D||tan ichi (たんいち) or 単1|
|9-Volt (rectangular)||kyuu bui1 (きゅうヴィ) or 9V|
NOTE 1 - This is just the easiest way to say "V" with a Japanese accent and be understood.
To remember the sizes, just start with D-batteries (the biggest common type) as number 1 and count from there. If you need triple-A's, they are the the 4th smallest from D thus, "tan-4". (Remember, there's no B-size and no single A-size.)
How to Ask for a Battery Size in Japanese
So you're in the supermarket and you can't find the right battery size you need. Here's how to use the sizes above to ask.
Excuse yourself (to get attention), say the size, then the word for battery, then the question portion of the sentence asking if they have it. For example, asking for AA batteries:
- In kanji ~ 単3乾電池がありますか。
- In hiragana ~ たんさん かんでんち が ありますか。
- In romaji ~ tansan kandenchi ga arimasuka
For more Japanese to get you started on your path to speaking fluently, here's a list of some basic Japanese phrases for beginners.