Wednesday, July 24, 2013

Are your 18650 Li-ion Batteries Fake?

 TaoBao has some hints here.  I've copied the pictures below and translated the Chinese text. ht: ahvttvsn.

Note the 2D Bar Code.  I think the white text identifies the manufacturer.

Looks good on the outside, but look more carefully.

The outside code is super-thin and elastic.
 Take off the covering and look on the inside.
 Quality of body and cap is matched perfectly.  It is not done by a counterfeiter.

Bare ("naked") cell diagram.
 Counterfeit vs. Genuine.

Counterfeit is only plated on top and has dull body.
Genuine is consistently shiny.

Note the reflection on fake and real.
There's more information on the vendor's page.  There's a chart showing the lousy power output of the fakes.


  1. This comment has been removed by a blog administrator.

  2. Interesting - the real one looks exactly like the cells seen inside a disassembled Tesla Model S 85kWh battery (there is a video of it on YouTube, and numerous pictures on either Tesla Motors' official forum or

    The cell shown here is marked NCR18650B. There is a newer version of this battery on the market now, called the NCR18650G, which bumps capacity to 3600mAh. It's super hard to find, almost noone has it in stock.
    Around the same time the NCR18650G started appearing on the market, Tesla Motors introduced a 90kWh battery option.

    (85000 Wh / 3.4 Ah) * 3.6 Ah is exactly 90000 Wh.
    So, it seems, Tesla is using NCR18650Bs in their 85kWh batteries, and NCR18650Gs in the newer 90kWh ones.