What Are Battery Date Codes?

Battery date codes typically are found on the tops of batteries, usually in one corner, and can only be seen when looking straight down at the tops of batteries. The first two digits in the date code are the most important. These are the digits that indicate both the month and year when the battery was shipped. The first digit is the month, indicated by a letter (A is January, B is February, and so on) and the second digit is the year (1 is 2011, 2 is 2012, and so on).