Battery Health and Charge Limits on Mac, iPhone and iPad: What Apple Offers and How to Use It
How to look after your battery on Mac, iPhone and iPad: Optimised Battery Charging, Charge Limit and which models and settings Apple supports.
All modern Apple devices use lithium-ion batteries, and they all wear out slowly. Apple’s battery features aim to slow that wear, not stop it. This guide explains what each device offers, where to find the setting and when it is worth using.
Why batteries wear
A battery’s lifespan is related to its chemical age. That depends on more than how old the battery is. Temperature history and charging pattern are two of the factors. As a lithium-ion battery ages chemically, it holds less charge, so you get less battery life and lower peak performance.
An iPad battery warms as it charges, and prolonged heat can shorten its lifespan. Reducing the time a device spends fully charged reduces the wear on its battery.
Two features to know
Optimised Battery Charging learns your daily routine and delays finishing a charge in certain situations, so the device spends less time full. Charge Limit lets you decide what counts as a full charge. A lower limit means less charge when you unplug, which is the trade-off.
On a Mac
Optimised Battery Charging has been on Macs since macOS Big Sur 11. Your Mac uses on-device learning to delay charging past 80 per cent when it expects to be plugged in for a long time, and aims to be fully charged when you usually unplug. When charging is on hold, the battery status menu shows “Charging On Hold”. If you need a full charge sooner, choose Charge to Full Now from that menu.
Charge Limit needs a Mac with Apple silicon and macOS Tahoe 26.4 or later, so it works on macOS 27 Golden Gate. Our macOS Golden Gate guide lists the Macs that can run it. Your Mac charges to within a few percentage points of the limit, then stops and shows “Charged to [%] Limit”. To set either feature:
- Choose Apple menu, then System Settings.
- Click Battery in the sidebar.
- Click the information button next to Charging, or next to Battery Health on some versions.
- Turn Optimised Battery Charging on or off, or set the Charge Limit.
With either feature, your Mac will occasionally charge to 100 per cent to keep its battery estimates accurate.
On an iPhone
On an iPhone 15 or later, open Settings, tap Battery, then tap Charging. You can choose a charge limit from 80 to 100 per cent in 5 per cent steps. When the limit is 100 per cent, Optimised Battery Charging is available. It is on by default when you set up an iPhone, and when it is active the Lock Screen tells you when your iPhone will be fully charged. Touch and hold that notification and tap Charge Now if you need it sooner.
On an iPhone 14 or earlier, open Settings, tap Battery, then tap Battery Health & Charging, and turn Optimised Battery Charging on or off. Turning off charging optimisations can increase wear on your battery.
With a charge limit set, your iPhone charges to within a few points of it, then stops. If the level drops more than 5 per cent while plugged in, charging resumes.
On an iPad
An iPad stops charging automatically when it is full, so it is safe to keep it connected overnight, and it reduces the charging current as the battery nears full. Charging resumes if the level drops below 95 per cent. On these models you can also choose an 80% Limit:
The 80% Limit is available on iPad Pro with M4 or later, iPad Air with M2 or later, iPad mini with A17 Pro, and iPad with A16.
Open Settings, tap Battery, then tap Battery Health to turn it on. With the limit on, your iPad charges to about 80 per cent, and starts again when it falls to about 75 per cent. It will occasionally charge to 100 per cent to keep its estimates accurate.
Which setting should you use?
If your MacBook or iPad lives on a desk and is plugged in most of the day, a charge limit is a sensible choice. If you rely on a full battery for travel, leave the limit at 100 per cent, or use Charge to Full Now or Charge Now when you need it. Optimised Battery Charging suits a regular routine, such as charging overnight.
If your battery seems to run out too fast
A charge limit can look like a battery problem, so check that first. Our guide to why a Mac battery drains quickly takes you through it. A slow Mac can also feel like a battery problem, so our guide to why your Mac is running so slowly is worth a look.
Need a hand?
If you would like help setting up your devices or checking a battery, see our Mac and Apple device setup and troubleshooting service, or contact Your Mac Tech.
