Hence it requires a signal / sound to put it off. In short, your battery gets a break when it's plugged in, whereas induction charging constantly uses, and therefore constantly stresses, it. Each little tick of the battery's capacity is another percent counted against the charging cycle, and another bit of wear and tear the battery has to deal with. As data streams to and from a device, the screen turns on to broadcast alerts, or music is played, and the battery is continually topped off by the charger. Induction charging, on the other hand, doesn't give the battery a break. When plugged into AC power an iPhone battery is getting a rest: It's being powered by the cable, and all the battery has to do is charge and wait for the cable to be removed. It all has to do with how a smartphone charges. There is a problem with the induction charging or the power source. There is no notification or beep or sound enabling settings when the phone is fully charged, regardless of the iOS version.
