I can't remember which post it was, but there was another thread that someone linked this battery and charger in, and I bought it at the start of this month, from the same sellers listed in the links in this OP. Took ~2 weeks to get here. Charger seems decent and works fine, has a red status light when battery is charging and turns blue when battery is fully charged. Battery can be inserted directly in the charger, or you can plug usb cable into the charger to charge the phone.
I bought 4 of the batteries. Upon inspection, I'm going to have to go with "very good knock-off", not genuine OEM, for the following reasons:
**On my battery that came with the phone, on the top of the battery (same edge that has the metal contacts) there is a short white strip that I can only assume is a water indicator strip. This is not present on the ebay batteries.
**The label itself on the battery is cut such that the gray label fits within the battery, with the dark gray casing of the battery forming a band along the top and bottom of the label. On the ebay batteries, the gray label extends all the way to the bottom of the battery.
**The stock battery has a 3D barcode located on the front-face of the label, in the lower right. The ebay batteries have no 3D barcode.
**The size of the font used for "SAMSUNG" and some of the other type on the front-face of the battery is slightly different between the two (ebay is smaller).
**The printed model/serial information on the bottom left of the front-face of the batteries on the ebay versions appear dark black and crisp, as if printed onto the label after the label was made, whereas on the stock battery the inking is matte in appearance as if printed during manufacture of the label as a single pass.
**On the back-face of the stock battery, toward the bottom center there is the CE logo left-of-center and two arrows circled around a 5 right-of-center. These two logo positions are swapped on the ebay battery.
**Stock battery is listed as "Made in China". Ebay battery is listed as "Made in Japan, Finished in China".
Other than the labeling differences, there is also a different molding pattern on the bottom edge of the battery housing itself. I don't have a precise enough scale, but I would also swear that the ebay battery feels just slightly lighter for some reason. Regardless, I charged the ebay batteries in the new charger, and they run the phone just fine. Just to be prudent, I will not charge them inside of the phone, but will keep them as a backup battery to swap in when I drain the stock battery, and recharge the stock battery in the phone at night. Despite differences noted above, performance for the products is more than adequate, and I would highly recommend them as being a great value for their cost.
Edit: Ahh,
Here is the first post I was referring to. I am too lazy to post pictures of the batteries, however. Maybe when it isn't 2:46am