I've tried shutting off my iPhone 6 AFTER plugging it in to charge, and it will turn back on. How can I make sure it stays off while charging so that it charges more quickly?
- Plug the phone in to power
- Then turn it off
If your charger is overloaded, faulty or your cable has issues, there could be an interruption of charge and the device will start up then. There's no way to prevent this necessary feature - it's a fail safe to turn on the device after replacing the battery or other system events that could cause the power to be low.
Just put it in airplane mode, it will achieve the same desired result.