I bought this in May 2017, and at first it was fantastic; discharged about about 0.36%/hour when not in active use, which meant it lasted about a week between charges.  Unfortunately, over the past month, it has rapidly degraded; it discharged from 50% to 33% in 3.5 hours this afternoon.  That's even worse than the previous batteries that I've had for this phone... they just don't seem to last more than a year or two... very disappointing.