I bought 2 of these off amazon and have zero complaints. They work great.
Those Anker batteries only lasted a year. They started expanding such that I couldn't close the back, and lasting only half a day. I bought a Samsung OEM battery and it has been working fine. https://www.amazon.com/dp/B00IN9HI2I/
I bought this one and it works great.
After a year of use, I replaced my battery and nearly doubled my battery life. This one cost me $10.00 and arrived in about a week.