Myth: Charging Your iPhone Overnight Will Ruin Its Battery

Overnight charging used to be a bigger concern back when battery management was less sophisticated — we’re talking about the days of the nickel-cadmium batteries that no smartphone has ever used. While the lithium-ion batteries used in all modern electronics have their issues, overcharging isn’t one of them.

The real problem is wear on the battery that will shorten its life, but today’s iPhones are built to handle your daily charging habits, with features designed to reduce battery wear and tear when you plug in your iPhone for long periods of time.

The real enemies of your device’s battery health are heat caused by ambient temperatures or prolonged use while your iPhone is charging, not simply being connected to power while you sleep. Overnight charging is perfectly harmless as long as you’re using a decent charger.

However, there are some settings worth checking if you want to keep your battery as healthy as possible. Go to Settings > Battery > Charging, and ensure Optimized Battery Charging is enabled. With this setting on, your iPhone will learn your usage habits to avoid charging above 80% until you’re ready to take it off the charger. If you have an iPhone 15 or newer, you can also use the Charge Limit setting to stop charging entirely at 80-95% to reduce the amount of time your iPhone stays at the more stressful 100% level.