Eneloop battery codes and numbers, what do they stand for?

Eneloop numbers:

The numbers 1, 2, 3 and 4, used in the product codes on all eneloops, as in HR-3UTG /BK-3MCCE /BK-4HCD are simply stating the size of the battery. These numbers are used on all batteries in Japan.

  • 1 stands for: D
  • 2 stands for: C
  • 3 stands for: AA
  • 4 stands for: AAA

単三 : Tan-San (san means three) which is the 3rd size. We call these AA batteries.

単四 : Tan-Yon (yon means four) which is the 4th size. We call these AAA batteries.

Take note that some foreigners get confused while shopping for batteries in Japan because of a mixup between size 3 = AA and size 4 = AAA. 

BK-3MCC code

Panasonic eneloop coding worldwide.

Made in Japan vs Made in China 

When you look closely to the overview page, you can see that from 2013 Panasonic started coding their batteries differently specifying the market region.

I will take the AA verions as an example.

BK-3MCC (produced in Japan)= no additional letter, Japan market only
BK-3MCCA (produced in Japan) = North American market and China
BK-3MCCE (produced in Japan)= European market/Russian market
BK-3MCCE* (produced in China)= South American market, Southeast Asian market, Australian market/New Zealand market.

If you are living in one of the above mentioned markets, you can see where your Panasonic eneloop batteries are sourced from. When you live in the US and you buy from an authorized seller you wouldn`t get any Chinese cells.
But when you live in Australia you can only buy Japanese cells when they are imported from other markets, and not through the authorized Panasonic dealers.

If you really want to make sure

  1. Check the package. On the back of each package it shows if they are made in China or Japan.
  2. Check the batteries. On each battery the country or production is printed.
  3. Check the claimed ratings. From 2015 all Japan made standard eneloops have a claimed 70% charge after 10 years.
    At the same time, from 2015, Chinese made standard cells have a 70% after 5 years.
  4. There are NO eneloop PRO batteries produced in China as of 2017, so all PRO eneloops are made in Japan.

* Note that the BK-3MCCE code is the same in different regions, even though one is sourced from China, and the other is from Japan. Independent tests suggest that Eneloops produced in China are inferior to Eneloops produced in Japan. See the Test page.  As stated above, when Eneloops with an E at the end of the code are purchased in Europe or Russia from authorized resellers, they will be sourced from Japan.

Reading the manufacturing date:

Panasonic uses codes to see when a battery has been produced. This started when Sanyo still produced the eneloop battery.
Every original eneloop battery has a production date, embossed on the side of each battery, just above the battery jacket seam. You can easily decipher it.
(If your eneloops have no code embossed on the side, or the code is printed, yours are likely counterfeits.)

The production code doesn`t have any color so you have to check where the seam is, and look up close.

Take a look at the pictures battery. It`s made in Japan.

The battery has the following code: 16-08 xx

The first 2 numbers indicate the year: 16=2016

The next 2 numbers indicate the month: 08=August

So this battery is a 4th generation Panasonic eneloop battery produced in August 2016, in Japan.

Manufacturing date