Battery Date Code Decoder for NiMH, Rayovac, Duracell, Eneloop, Energizer, EBL (AA/AAA)

Obtuse Penguin

Newly Enlightened
Joined
Aug 18, 2015
Messages
5
I was scouring the internet for Rayovac battery date codes for some NiMH batteries I have and the only list I could find was incomplete and ended in 2011. Rayovacs stamp was difficult to decode because their coding scheme seems to be random lettering in no order (except for the AEIOU and RAYOLITESHUM lol). I also have some Duracell NiMH made in Japan aka Duraloops and could not find precise information on them. I called both manufacturers and got a mostly complete list that I wanted to provide for anyone who is interested. My Rayovacs are from 2014 and Duraloops from 2015 and they are both running strong in 2022 after 100's of cycles. Side note and totally anecdotal but the Rayovacs honestly surprised me a bit considering they are made in China. Battery age is useful in determining application, cycles, usage, and general health of a battery, for example I use older or "tired" batteries with high cycle counts for low drain devices like remotes or a computer mouse. Hopefully this information can help someone.


Rayovac:

MDY-X month/day/year/country of origin (stamped/embossed)

Y=2007
P=2008
B=2009
G=2010
W=2011
F=2012
J=2013
A=2014
E=2015
I=2016
O=2017
U=2018
R=2019
T=2020
N=2021
X=2022
K=2024? (idk why she gave me this one but could be the accurate future code, forgot to ask 2023)

R=Jan
A=Feb
Y=Mar
O=Apr
L=May
I=Jun
T=Jul
E=Aug
S=Sep
H=Oct
U=Nov
M=Dec

Day:

A=1, B=2, C=3....... V=22.....Z=26......2=27,3=28,4=29,5=30,6=31

Country of origin:

O=USA
J=China
S=China
Y=China
R=Malaysia

Example Rayovac code:

SAV-S = September 22 2014 - China

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Duracell NiMH/Duraloop:

YDDDXXXXXX (stamped/embossed)

DDD format for 365 days

Y is Last digit of year so 2015=5, 2016=6, 2020=0, 2022=2

The last 6 XXXXXX are mfg code that the agent did not know

Example Duracell code:

50718676YF = 2015, 71st day, so March 12th 2015 based on Julian calendar

-------------------------------------------

Eneloop: (most people know this but I figured it wouldn't hurt to include it)

YY MM XX (stamped/embossed)

The XX is an alphanumeric mfg code, not sure what it means

Example Eneloop code:

22 - 03 YG = March 2022
15 - 10 RG = October 2015

--------------------------------------------

Energizer:

Could not find a ton of info on current date codes for NiMH Energizers

Appears to be MM-YY

Example Energizer Code:

CO 4-15 OMP = April 2015

-------------------------------------------

EBL:

No date code printed or stamped

All I know is they are made in China, seem to be "okayish" quality from my own and user reports.

-------------------------------------------

Information current as of 6/22/2022

Feel free to add any other brands to the decoder!
 
Last edited:

WC8KCY

Newly Enlightened
Joined
Nov 9, 2020
Messages
34
Thank you so much--I have several Rayovac cells and this is very helpful!
 

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