How to tell if your eBay Sony np fw50 info lithium Battery is Fake 

What was the fake serial number they both had?

so the battery that came with my camera has a black sticker, and so does the fake one that i bought. The only problem is i switched them and now i don't know accurately which one is fake and which one is original...

Genuine is 1020mAh and those fakes are marked 1080mAh on the packaging.

you didn't notice the battery capacity printed is different from the original...

Do they have the same weight?

but sony original is made in japan and its 1080mah. so you cant say what 1080. i have slight different battery. got it with my camera. i do not have white sticker on battery, but black one. but still have japanese text on battery printed on it, it wasnt looked like fake one. holograms also differents. so i do not know how actually original looks like. i am in europe. shoult be original made in japan?

I am from Spain, and have an original kit a5100 battery that is exactly the same and same labels with black background that your "fakes batteries" for me, the fake looking battery is your "genuine" battery ;)

Just to add.. On the front of the packaging under the black square on the right that has a battery symbol and 79% written in a black box. The real battery will say: "Accurately calculates remaining power in %" The fake says: "In % accurately display the residual battery power". That's one thing that slipped by... The awkward Chinese to English translation gives it away..

I bought 4 and I am now returning them. I didn’t even open them.

Thank you, good job.

Tq so much