# How to Know Panasonic 18650 Battery Manufacture Date Code



## tomobattery (Aug 12, 2015)

New version of Panasonic 18650 Battery has 2 bars – a narrow bar and a wide bar. But the old version only has one narrow bar on the PVC. If you see a Panasonic 18650 battery has dot matrix on its top, it must be very old and be manufactured before 2009.





No matter new or old version, the same date code rule is followed.




You saw the 4 numbers(sometimes numbers+letters) on the bottom of the battery? They indicate the battery manufacture datecode.
_1. The first digit = year(0 = 2010, 1 = 2011, 2 = 2012, 3 = 2013, 4 = 2014, 5 = 2015, and so on)._
_ 2. The second digit = month(1 = Jan., 2 = Feb., 3 =Mar., 4 = Apr., 5 = May., 6 = Jun., 7 = Jul., 8 = Aug., 9 = Sept., 10 = X, 11 = Y, 12 = Z)._
_ 3. The third and the fourth together = day(01, 02, 03, 04….29, 30, 31).

_According to the rules, the battery above is made on 2013-01-26.

The source is from http://www.tomobattery.com/blog/how-to-know-panasonic-18650-battery-manufacture-date-code/


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## psychbeat (Aug 13, 2015)

Awesome- thanks for the info!


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## markr6 (Aug 13, 2015)

Nice and simple. I wish all manufacturers used the same format. I have all 2013 and 2014 NCR18650B cells. Wow, time sure flies by! Everything else is fairly new, either without codes or with wrappers covering the codes, so I take note.


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## kreisl (Aug 23, 2015)

Nothing knew because we always new it, Panasonic is (still) the leading LiIon battery manufacturer, followed by Samsung, and then LG:

Report: Panasonic largest li-ion battery cell producer, *06. August 2015*

Thanks Tomo for the informative info!


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## kreisl (Jan 2, 2016)

I was looking for this OP , i had confused it with batterybro blog , google search did it for me , it was tomo blog , i see. Both sites are easily confused.

So what about *Sanyo NCR18650GA* batteries? The stamp is clearly Sanyo, wrapper is red, so it is a Sanyo imho. However we know NCR's as Panasonic and i would decode the datecode as Panasonic date code : 5430 = 2015-04-30 . So not too old, not too shabby huh.

The manufacturer's datasheet looks good too.


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## gunnish (Aug 21, 2016)

But how are the ones from before 2009 denoted? Also, when did they change from one band to two?


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