2 November 2021
JIS (Japanese Industrial Standards) defines [Recommended usage period] as “a period in which the battery operates normally if it is started to be used within that period and satisfies the performance such as the duration specified in JIS”. The recommended expiration date is 2 digits per month-year (09-2022 for September 2022), and is displayed on the battery itself or on the package of small batteries such as button batteries.
The [Recommended usage period] is not set in JIS and is to be agreed by each battery manufacturer.
Maxell’s alkaline batteries “Voltage”, AAA to AAA, have a recommended usage period of 10 years, and the battery body displays the 2-digit month-year number 10 years after manufacture.