LINK to Apple: https://support.apple.com/en-us/HT210512
With iOS 13 and later, Optimized Battery Charging is designed to reduce the wear on your battery and improve its lifespan by reducing the time your iPhone spends fully charged. When the feature is enabled, your iPhone will delay charging past 80% in certain situations. Your iPhone uses on-device machine learning to learn your daily charging routine so that Optimized Battery Charging activates only when your iPhone predicts it will be connected to a charger for an extended period of time. The algorithm aims to ensure that your iPhone is still fully charged when unplugged.
When Optimized Battery Charging is active, a notification on the Lock Screen says when your iPhone will be fully charged. If you need to have your iPhone fully charged sooner, touch and hold the notification and then tap Charge Now.
Optimized Battery Charging is on by default when you set up your iPhone.
If you want to change your charging option:
- With iPhone 14 models and earlier, go to Settings > Battery > Battery Health & Charging and turn off Optimized Battery Charging.
- With iPhone 15 models, to choose between Optimized Battery Charging, 80% Limit, and None, go to Settings > Battery > Battery Health & Charging > Charging Optimization and choose an option.
Turning off charging optimizations can increase wear on your battery and reduce its lifespan.
About 80% Limit with iPhone 15 models
With iPhone 15 models, you can choose between Optimized Battery Charging, 80% Limit, and None.
When you choose 80% Limit, your iPhone will charge up to about 80 percent and then stop charging. If the battery charge level gets down to 75 percent, charging will resume until your battery charge level reaches about 80 percent again.
With 80% Limit enabled, your iPhone will occasionally charge to 100 percent to maintain accurate battery state-of-charge estimates.