Dick Ovrid sent this useful info for figuring out the date of your Sanyo batteries. You may have to remove the shrinkwrap from your pack to get to the code on the individual cells... First Character is the year Y=1994 Z=1995 A=1996 B=1997 C=1998 D=1999 E=2000 F=2001 G=2002 H=2003, etc. The Second Character is the month of the year: A=Jan B=Feb C=March D=April E=May F=June G=July H=Aug I=Sept J=Oct K=Nov L=Dec