Authenticity of "Brand Name" batteries

[A..dam]

How to ensure that the premium one pays for the top brand battery (Panasonic, Samsung, etc.) results in delivery of a real stuff?

Recently, I have received an electronic item (not battery) from China via a reputable on-line retailer and it was fake.
Actual item was identical to original but, fortunately, I have spotted a couple of grammatical errors on otherwise a very well done packaging.

 

[Nobuo]

I think to check authenticity there are 3 basic things:

First, use an analyzer charger and do a pair of complete cycles, checking cell temperatures.

Second: Weight the cell. The differences between weight of same cells are extremely low 0.1g maximum or less. As I found on my measurements.

Third: Checking printed info could you made you realize the are fake data, doing a quick research.

 

[spinningmagnets]

There are a shockingingly high percentage of counterfeit 18650's on the market. The most frequently found are the Sony VTC4 and VTC5. It doesn't mean you got a horribly bad cell (1C, 1.6A, at 1600-mAh), you might have purchased a very good fake that is a $4 cell in a perfectly counterfeited $6 cell wrapper. After the Fukushima disaster, there were millions of legitimate VTC cells in warehouses across the globe (most slated to go into Makita cordless tool battery packs, among others). However, Sony moved their VTC cell manufacturing to the Philippines and China (insert sarcastic observation here).

To be clear, if you buy a Makita battery pack, and it is one that has Sony-labeled cells inside it...they are genuine. It is the loose cells that are sold individually to vape and flashlight customers that are highly suspect. They can even be found with all the proper shipping certificates guaranteeing authenticity. The only true test is to get a sample, and run a few cycles on them, then...test capacity. Then put them on a controlled amp-draw that meets the factory spec and see if they get hot. The full capacity is tested at 2A drain, and if it is factory-rated as a 20A cell, it should barely be warm in your hand at a continuous 20A.

Some fakes even have a very tiny button-cell inside a legitimate 18650 shell (charger is a Soshine SC-S7):

 

[A..dam]

The testing of batteries is time consuming, requires extra equipment AND might not provide ANY proof of authenticity.
A fake might have similar capacities, weight, voltage etc., but fail/decline in performance after small # of cycles.

Hence a call: list reputable vendors (and their products) which were never caught cheating...

 

[dogman dan]

As always, EM3ev. But you were asking about loose cells I'm sure.

Reputable places to buy those?

 

[A..dam]

I am looking for high quality 36 V pack which will not involve taking second mortgage...

As for loose 18650 I was very satisfied with Orbtronics
http://www.orbtronic.com/18650-battery

 

[ebent]

That is a hard equation. High quality and low price. My answer for high quality is All Cell from Chicago. If it matters on freight to get it from Canada Grin technologies sells them. But it is not cheap. I rationalize cost is one time for a long time. If I take risks I may win or I could finally get it right on the second or third try and be money and time behind. I take risks but not on batteries...