I love my HTC One, it’s so beautifully designed and the battery last long as I expected. However, something went wrong with the battery 3 months later after I happened to install an app. The battery started to drain fast like I charged it full before I went to sleep, the phone was power off as it’s out of capacity when I woke up the next morning. I had to charge 3 times a day even I removed the app the next day. Things got better after I asked on Reddit, someone told me to calibrate the battery. Then I searched on Google about how to calibrate Android phones. Now my phone is back to work again. My “repair” experience is that always ask and Google on powerful internet if you have no ideas.