What is Optimized Battery Charging on iPhone? (And the 80% limit)
Keeping a battery at 100% for hours wears it out faster. Optimized Battery Charging avoids that by learning your routine.
How it works
Lithium-ion batteries age faster when they sit at 100% for hours. Your iPhone learns when you usually charge and unplug, for example overnight, and holds at 80% for most of that time. It only works with a routine; charging at random times charges straight to full.
The fix
Turn it on or off, or set a limit
- 1
Open Settings › Battery › Charging (Battery Health & Charging on older iOS).
- 2
Turn Optimized Battery Charging on or off.
- 3
On iPhone 15 and later, choose a Charge Limit between 80% and 100% if you prefer a fixed cap.
Frequently asked questions
Should I leave Optimized Battery Charging on?
Yes, for most people. It only delays the last 20% when your iPhone predicts it will be plugged in for a long time, like overnight.
Is the 80% Charge Limit better?
It reduces wear a little more, but you always have less battery available. It suits people who rarely use more than 80% in a day.
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