What does a battery date code sticker indicating D6 mean?

A battery date code sticker with the designation D6 typically signifies that the battery was shipped from the factory in April 2006. The format used here often indicates a combination of letters and numbers where the letter corresponds to the month and the number represents the year. In this case, "D" denotes April (as it is the fourth month), and "6" refers to the year 2006. Understanding this convention is crucial for determining the battery's age and ensuring that it is appropriate for use, as it helps in assessing the freshness and reliability of the battery.