The first character from the left is a letter. It represents a month of the year. A represents January; B denotes February; C signifies March, and so on. The second number from the left denotes the year the battery was sent from the plant. 4 corresponds to 2004, 5 corresponds to 2005, 6 corresponds to 2006, 7 corresponds to 2007, 8 corresponds to 2008, 9 corresponds to 2009, 0 corresponds to 2010, 1 corresponds to 2011, 2 corresponds to 2012, and so forth.