How to identify Samsung 18650 battery manufacture date code?

There are 3 lines of printing on the Samsung 18650 battery cells.

The first line shows the chemistry(ICR or INR), model number and some times with the place of origin, such as INR18650-35E, ICR18650-26F M(M means made in Malaysia).

The second line shows the brand name(SAMSUNG) and factory(SDI means produced in Korea or other branches, SDIEM means produced by Samsung Energy Malaysia).

The last line shows the date code with 3 or 4 numbers or numbers + letters. Since 2010, most of date code are changing to 4 numbers or numbers + letters.

1. Date code with 3 numbers or numbers + letters, e.g. code: 813

The first number "8" = Year (2006=6; 2007=7; 2008=8; 2009=9, and so on...)

The second number "1" = Month (Made in Korea, JAN=1; FEB=2; ... SEP=9; OCT=A; NOV=B; DEC=C. Made in Malaysia, JAN=P; FEB=Q; March=R ... OCT=Y; NOV=Z; DEC=0)

The third number "3" = Week

Therefore, code: 813 means the battery made in 2016, the third week of January.

2. Date code with 4 numbers or numbers + letters, e.g. Samsung INR18650-25R code: 2F85

The first number "2" for Samsung internal identification

The second letter "F" = Year (2012=C; 2013=D; 2014=E; 2015=F, 2016=G, and so on...)

The third number "8" = Month (Made in Korea, JAN=1; FEB=2; ... SEP=9; OCT=A; NOV=B; DEC=C. Made in Malaysia, JAN=P; FEB=Q; March=R ... OCT=Y; NOV=Z; DEC=0)

The third number "5" = Week

Therefore, code: 2F85 means the battery made in 2015, the fifth week of August.