Just to provide a couple other options if you don't want to mess around with ebay sellers and whether they're genuine or not:
AC's own ShopAndroid:
Samsung 3220mAh Standard Battery for Galaxy Note 4 - Android Batteries - ShopAndroid
These appear to be genuine Samsung (bought in bulk) but they don't come with the plastic carry case. I bought 2 from them a few months ago and so far they're working great.
Another option yet is Verizon:
Samsung Standard Battery for Samsung Galaxy Note 4 - Verizon Wireless
Picked up 2 of these as insurance when I wasn't sure if the ones from ShopAndroid were genuine or not. These do come with the plastic carry case.
P.S. - I originally had 2 on order directly from Samsung, but canceled after a month waiting (at which point they had gone on back order).