Originally Posted by
ToSRQ
This is similar to "turn off all electronic devices before takeoff"
Not exactly. It is "recommended" to not charge to full. It is more like "Even when the seat belt is off, it is recommended that you still fasten your seatbelt." BTW, unless you are charging the phone at by the gate or in the lounge, it is not possible to have your phone at 100% during takeoff. When I am sitting by the gate, 80% of the people are looking at their phones or listening to music from their phones.