In short, in order not to generate more pointless controversy, Apple itself (in this case the engineer Michael Tchao) has clarified how the system and load cycle of an iOS device works .
All iOS devices, from the first one launched to the market, mark 100% of the equipment recharge slightly before it is completed. This way the device will continue charging until it reaches 100% and here comes the interesting thing… the device will then stop charging the battery to use it for a few minutes and then return to the charge until it reaches 100% and starts the cycle again.
This behaviour is done to prevent overcharging of the battery and also to improve battery life. The question everyone asks is why no one has noticed it before.
Easy: in the battery of small devices such as the iPhone and until now (although to a lesser extent) the iPad 2, this phenomenon was difficult to detect , with the enormous increase in the battery of the iPad this detail is detected much more clearly.