What Happens If I Charge My Phone Overnight. As a result it degrades the capacity much sooner. If your phone is plugged in the screen is locked and the phone is connected to WiFi it will back up every night assuming you have iCloud back up enabled and be fully charged and ready to go in the morning.

But leaving your phone in the charger overnight even when its fully charged wont do much to change how frequently its battery runs through cycles. Are advising me to not charge my phone overnight. The amount of charge going into your device shouldnt be an issue as most are smart enough to stop taking a charge.
Charging Your iPhone Overnight Shortens Its Battery Life.
By charging your phone overnight youre increasing the amount of time it spends with the charger. This means they gradually lose their ability to hold a charge. But leaving your phone in the charger overnight even when its fully charged wont do much to change how frequently its battery runs through cycles. Though I do turn quick charge off as its pretty pointless for overnight charges.
