Panasonic doesn't make protected cells, just the unprotected cells.
Re-sellers take the new unprotected Panasonic 18650 and add the protection to it, and re-wrap it with their own logo/label, etc.
18650 now a days, are normally made in mah ratings of 2600, 2900, 3100, and 3400, with some 3600 just coming out. (not widely available yet).
If you see an 18650 with the above ratings, its normal (Not real per se, but at least a normal nominal mah rating)
If you see anything HIGHER than that, or between those mah ratings (IE: 3000 mah) its a fake cell. (In the future of course, all of the above will change...but as of now...you can go by it)
If its an IMR 18650, the nominal mah ratings are again different...but IMR do not require protection at least, etc.
So its 100% OK to take the new Panasonic 18650 and add protection and/or a new private label to resell it as your brand cell.
Its only a problem for the consumer when an unscrupulous re-seller DOESN'T use a new cell, and/or uses a fake or recycled PCB, etc, lies about the specs, and sells the end result as a new 18650.
Selling you a used laptop cell as new means that its internal resistance is going to be higher, and, if you use a device that uses two or more in series for example, the cell with higher internal resistance is going to act as a resistance heater, and, then, bad things can happen.
It can internally short, causing similar bad things, even just in the device that uses ONE cell, or in your charger, etc.
If its a new cell, say a 2400 mah, but labeled higher, so you might think its OK to match with another of the same mah...you end up with flow INTO the lower mah cell, potentially reversing the current flow you wanted.
The least harmful, except to your wallet, is when you only use one cell per device, and its a new but over-rated cell...so the device simply doesn't run as long as you thought it should, or, at least as long as it should have....so you were ripped off, but, at least your house doesn't burn down, etc.
Again, the problem comes back to the dang LABEL.
They can label it anything they feel like. Literally. Anything goes. Say its a Panasonic, say its a Genuine Panasonic. Say its got 10,000 mah and 100 amp. Whatever you want. Make the label LOOK LIKE the real ones, or, if a competitor's is selling well, make it look like the competitor's cells....right down to your competitor's logo, etc.
Sometimes, they screw up, and there are mistranslations and typos...a potential clue as to their quality, BUT, even the real cells that are private labeled can too, so, its not a fool proof test either.
Finding a seller who does the QA/QC on THEIR suppliers, etc, is vital.
BTW - The CHARGERS can be counterfeit as well, etc. AND just as dangerous, with shorter cell life as the least of the issues.
