Hello!
Can anyone tell me when the Samsung ICR18650 26FM below was manufactured?
Sorry, who can tell me how can I attach a picture?
Thanks a lot! 
Thanks a lot!
The question of samsung date codes has been asked a 100 times on this site ... no one seems to know for sure .
here's some info from Ubehebe's thread
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A mystery perhaps solved???
More searching turned this up from a product sheet for the samsung 15q 18650 on how to descipher the date code.
+++++++++++++++ begin samsung samsung date code description ++++++++++++++
Model and Date code Marking : there are three lines on the cell tube as follows.
Line 1 : INR18650-15Q —- Cell Model Name
Line 2 : SAMSUNG SDI —-Cell Maker
Line 3 : 096 —-Part number
■
Lot marking : There are two lines on the cell metal can as follows.
Line 1 : 1128 —- 1st digit: line number ( “1” means Line No. 1)
2nd~3rd digit: Model Name (“12” is INR18650-15Q)
4th digit: Year ( “8” is 2008)
Line 2 : 4E1C5 —- 1st digit: Month ( “4” is Apr. ; A is Oct., B is Nov., C is Dec)
2nd digit: Date (“E” is 15th day ; 1, 2 is 2… , 10 is A, 11 is B…)
3rd digit: Serial No. of winding
4th digit: Reel No ( “C” is C reel ; A is A reel, B is B reel, … F is Freel)
5th digit: Winding Machine No. ( “1” is No.1 winder)
+++++++++++++++ end samsung date code description ++++++++++++++
Source is:
http://www.batteryspace.com/prod-specs/6615.pdf
Some of my mystery date codes:
954
2C51
2C44
2C63
Some creative guesswork (using ONLY the first three numbers) would mean that 954 is 2009, May 4. Using the first three numbers makes some sense with the description as the fourth number is the reel number (?). Whatever the h a reel number is.
2C51 = 2012, Dec. 5
2C44 = 2012, Dec. 4
2c63 = 2012, Dec. 6
Hope this helps!
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BUT ............
later he says .. he was wrong >
Date code mystery solved!!!!
I positively 100% figured out the samsung date code mystery if anyone cares.
And I am a dummy. I looked in the wrong place!!!
When cleaning up another six cells today, I noticed that there areBARELY LEGIBLE numbers UNDERNEATH the wrapper, printed on the actual metal battery can. DUH!!! as you may remember, that’s exactly what the Samsung date code explanation says: “There are two lines ++ON THE CELL METAL CAN+++ as follows…” DUH!!! The caps are mine. It’s on THE CAN. NOT on the wrapper.
These are barely readable through the wrapper but they are definitelyTWO lines in the the exact format cited in the explanation, and they are now easily translated. Here are the two lines from one of today’s batteries:
G099
5O9D2
Okay, so the last number in the first line is the year. in this case 2009. That’s the important one. These batteries are from 2009, not the best date possible, but not the worst.
Second line:
First digit = 5 is the month, so May.
Second digit is “O” (not a zero, but the letter “O”), which is 25 (directions say “E=15, so count up from there: F=16; G=17, H=etc.).
So it’s May 25, 2009!!!
HOORAY!!! I figured it out.
the 3rd, 4th and 5th digits don’t really concern us. But they mean: 3rd digit (serial number of winding = 9); 4th (Reel Number = D); And 5th number is the winder machine used, number 2 in this case.
Man, you need a degree in cryptology to figure this out.
https://budgetlightforum.com/t/-/21007
****
but if i recall correctly even this last post of ubhebe's proved to be incorrect because a bunch of laptop packs dated 2010 on the outside of the pack had cells inside that we supposedly newer ...one of those kind of impossibilities ..So i go back to my original statement of ...Even samsung doesn't know
only god knows
YMMV
B
Thanks for the information.
But I am still confused about something and hope someone can help me.
Please see the picture below. Does any one find out any differences between the first and the second battery?
Is this information helpful?
_It’s very easy to recognize the date code early Samsung 18650 batteries. There’ re 3 lines on the battery body and the third line is the date code.The first digit = Year, the second digit = Month, and the third digit = Week.
However, from the year of 2010, Samsung changed its code rules. Moreover, Samsung lithium batteries are divided into SDI ( are manufactured in Korea) and SDIEM ( are manufactured in Malaysia). And the date code rules of SDI and SDIEM are different.
The battery below is from SDI, and on the second line, we can see “SDI”.
On the third line of the PVC, there’ re 4 digits.
1. The first digit = Version
2. The second digit = Year ( A = 2010, B = 2011, C = 2012, D = 2013, E = 2014, F = 2015).
3. The third digit = Month (1, 2, 3……9, A= 10, B = 11, C = 12).
4. The fourth digit may mean Day, not so sure. It seems that, 3 means the day of 03, 13, and 30 at the same time.
So can be figured out that it was manufactured in July, 2014.
The battery below is from SDIEM, and also has 4 digits.
- The first digit = Version
- The second digit = Year ( A = 2010, B = 2011, C = 2012, D = 2013, E = 2014, F = 2015).
- The third digit = Month ( O = 1, P = 2, Q = 3, R = 4, S = 5, T = 6, U = 7, V = 8, W = 9, X = 10, Y = 11, Z = 12).
- The fourth digit may mean Day, not so sure. It seems that, 3 means the day of 03, 13, and 30 at the same time._
The source is http://www.tomobattery.com/blog/samsung-18650-battery-manufacture-date-code/
I think this post is much more detailed.
That’s very helpful. Thanks.
Moved this post to here:
Recent research 
has shown that date code is on the can, line 1, digit 3 and 4, and, in the case of wrapper text line 3 has 4 digits, it is digit 2 and 3 here.
The format is YM so F2 is 2016, feb.
Follow the link in previous post and read post #12 there for an explanation.