Yesterday evening when I got home I decided to do things a little more methodically. I noted that the battery icon was showing battery fully charged. I then opened the phone and unplugged the battery. On re-installation and power up icon now showed about half. I loaded Battery Solo Widget. BSW showed 52%. I put it on the OEM charger (#ETA0U80JBE) which is 5.0V at 1.0A. By the time I was about to go to bed the phone had reached 100% according to BSW. I repeated the battery removal procedure and it still showed 100%. I dimmed the display and went to bed. This morning after six hours sleep for me and the phone BSW still showed 100%. I repeated the battery removal procedure. BSW now showed 74%. WTF! Zero usage but a 26% drop in battery charge. I recharged it to 100% before leaving the house. Now at work two hours later it shows 98%. I am going to monitor charge till lunch time then repeat the battery removal procedure. Then likewise for the afternoon. I will report again this evening.