Reddit reviews PowerBear Samsung Galaxy Note 4 [Extended Series] - 7500mAh Extended Battery with Bare Black Back Lid Cover - Compatible with SM-N910, N910T (T-Mobile), N910P (Sprint), N910A (AT&T) & N910V (Verizon) - 2.5x More Power

This one I have the same complaints at the bottom about the back cover but thats because I dropped it more than a few times.

Marketing and availability was poor. They didn't push for them like the carriers do.

US buyers are still stuck in the "oh, monthly? Cheaper!" mindset.

I've bought two S4 devices specifically for the "Play" ROM. They are still great devices today, especially outfitted with a flip case and extended battery.

I ended up going with this one from Amazon: https://www.amazon.com/gp/product/B00OQLMJR6/ref=oh_aui_detailpage_o05_s00?ie=UTF8&psc=1

I chose this one because it was Prime eligible, and appeared to be one of the few legitimate "new in retail box" batteries for sale on there. I was really skeptical about buying one of the dirt cheap batteries that claimed to be official, like: https://www.amazon.com/Samsung-Galaxy-Standard-Battery-3220mAh/dp/B00WBH9QQE/ - I made that mistake with a phone in the past and it was not a great experience.

I've been using it regularly for about 3.5 weeks now and it works great. I'm considering getting another as a spare since I plan to have my Note for a long time.

If you don't care whether or not the battery is OEM, I've heard good things about PowerBear: https://www.amazon.com/PowerBear-Battery-Samsung-T-Mobile-Warranty/dp/B01FF1XJX8/ - someone linked to the 7,500mAh version in this thread: https://www.amazon.com/PowerBear-Samsung-Extended-Battery-Protective/dp/9652676764

Good luck!