The battery I received didn't t fit well, had to use a screwdriver to pry it in its place, the bottom of the battery kept sliding upwards, so the back cover of the phone doesn't close.
While using the battery, after the charge of the battery goes below about 55%, it will suddenly drain very quickly, causing the phone to switch off without even a low-battery warning.
Then, when the battery is completely empty, it won't charge again. The phone displays an exclamation mark, indicating something is wrong.
EDIT: My complaint was handled very well by MiniInTheBox, so I changed my one-star review to 2.5 (rounded up to 3) for the effort.