[NOhara24]

This is unsettling to me...as I have the same battery you do. Assuming you're still running it the same way you were when you had the stock battery (Connections and screen brightness wise) Try running the battery all the way down, and then charge it back to 100%. And then don't charge it every night. Mine will typically last me 2 days with moderate use. Did you charge it for 8 hours out of the box like they told you to?