Phone CleanerWhat Optimized Battery Charging does
Apple designed these charging features to reduce the time the battery stays fully charged. With Optimized Battery Charging, iPhone learns your daily routine on the device and, when it expects to stay on the charger for a long time, pauses at 80% and finishes just before you usually unplug. If you unplug at 7 a.m., it may hold at 80% overnight and reach 100% shortly before then.
It needs a routine. It works where you spend the most time, such as home and work, and needs at least 14 days to learn your habits and at least 9 charges of 5 hours or more in a place. When you travel or charge at odd times, iPhone charges to 100% without pausing.
How to turn on Optimized Battery Charging
- Open Settings and tap Battery.
- On iPhone 15 or later, tap Charging. On iPhone 14 or earlier, tap Battery Health & Charging.
- Turn on Optimized Battery Charging. On iPhone 15 or later, it is offered when the Charge Limit is 100%.
Optimized Battery Charging uses your location to learn where you charge, and Apple says none of that is sent to Apple. If it never starts, check that Location Services is on in Settings › Privacy & Security, and under Location Services › System Services, that System Customization and Significant Locations are on.
Charge Limit: stop at 80% (iPhone 15 and later)
On iPhone 15 and later, Settings › Battery › Charging lets you set a Charge Limit between 80% and 100%, in steps of 5%. iPhone then stops charging at that level, whatever your routine, which suits an iPhone that charges often or stays plugged in for long periods. iPhone may also suggest a limit based on how you charge. iPhone 14 and earlier have no Charge Limit.
Now and then it still charges to 100%, so the battery percentage stays accurate. To charge to full once, tap Charge to 100% in Settings › Battery; in Charging, Allow Until Tomorrow lifts the limit until 6:00 a.m.
What percentage should you charge your iPhone to?
There is no need to wait for 0% or to unplug at a set number. Apple says partial charging throughout the day won't harm the battery. iPhone charges fast to about 80%, then slows down to reduce stress and heat. Optimized Battery Charging, or a Charge Limit, helps the battery last longer still.
If you charge overnight, Optimized Battery Charging already holds the battery at 80% for most of the night. If your iPhone 15 or later is often plugged in for hours at a time, an 80% Charge Limit keeps it from sitting full. To store an iPhone for a long time, leave it about half charged.
Heat matters more than the number
Apple advises charging between 0° and 35° C (32° to 95° F), out of direct sun, and taking off the case if the iPhone gets hot while charging. When it is too warm, iOS slows or pauses charging and the Lock Screen may say Charging On Hold until it cools.
Not the same as Optimize iPhone Storage
Optimized Battery Charging is about the battery. Optimize iPhone Storage is a different setting, in iCloud Photos, that keeps space-saving versions of your photos on the iPhone and the originals in iCloud. One has no effect on the other. The storage setting is in Settings › your name › iCloud › Photos.
