How to Set a Charge Limit on iPhone 18 Pro (iOS 27)

To set a charge limit on an iPhone 18 Pro or iPhone 18 Pro Max running iOS 27, open Settings > Battery > Charging and pick a limit between 80% and 100%, in 5% steps. The phone then stops charging close to that level. If you keep the limit at 100%, you can use Optimized Battery Charging instead, which can pause charging at 80% and finish closer to when you usually unplug.

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Before you start

Apple's Charge Limit support article gives these steps for iPhone 15 models and later, which includes the iPhone 18 Pro and iPhone 18 Pro Max. The steps below are for iOS 27. No app, backup or data reset is involved: it is a single setting.

How to set a charge limit on iPhone 18 Pro

Open the Settings app.
Tap Battery.
Tap Charging.
Choose a limit: 80%, 85%, 90%, 95% or 100%.

Apple says the iPhone charges "to within a few percentage points" of the limit and then stops. If the level falls by more than 5% while it is still plugged in, charging starts again and stops near the limit once more.

{tip}Not sure which number to pick? Tech Between The Lines suggests 85% if you usually finish the day with charge left over, and 100% with Optimized Battery Charging if you need all the runtime you can get.

How to charge to 100% just once

If you need a full battery for one day, you don't have to give up your limit. Apple's iOS 27 user guide lists two ways:

Go to Settings > Battery > Charging, choose 100%, then tap Allow Until Tomorrow. Your old limit returns at 6:00 a.m.
Go to Settings > Battery and tap Charge to 100% to fill up sooner than scheduled.

If you instead tap Set Limit to 100%, the limit stays at 100% until you change it again.

How to use Optimized Battery Charging instead

Optimized Battery Charging only appears when the limit is set to 100%. On iPhone 15 models and later, 100% with Optimized Battery Charging on is the default setup.

Go to Settings > Battery > Charging.
Select 100%.
Turn on Optimized Battery Charging.

The feature uses on-device learning of your daily charging routine and, in certain situations, delays charging past 80%. When it is active, a Lock Screen notification tells you when the phone will be full. If you need a full battery right away, touch and hold that notification, then tap Charge Now.

Charge limit or Optimized Battery Charging: which to choose

Setting	What it does	Best for
Charge limit 80% to 95%	Stops near the chosen level	Light users, phones left on chargers
100% + Optimized Battery Charging	May pause at 80%, based on your routine	Regular overnight charging routine
100%, optimization off	Charges straight to full	Days you need maximum runtime

You can't run both at once. A limit below 100% replaces Optimized Battery Charging.

{warning}Turning off charging optimizations entirely can increase battery wear and shorten its lifespan, according to Apple. If you switch to 100% without optimization for a trip, consider switching back afterwards.

If it doesn't work

The phone went to 100% anyway. This is expected. With a limit below 100%, the iPhone occasionally charges fully so its battery percentage estimate stays accurate.
It stops at 78% or 82% instead of 80%. Apple only promises the phone stops within a few points of your chosen limit.
Optimized Battery Charging is missing. It is only shown when the limit is set to 100%. Change the limit first.
Optimized Battery Charging never kicks in. Apple says it needs at least 14 days to learn your habits, plus at least 9 charges of 5 hours or more in one location.
You see a suggested limit. iOS can recommend a limit based on how you use the phone, for example 95%. It is only a suggestion. You can keep your own setting.
An iPhone 18 Pro Max stays at 80% after a repair or trade-in. This comes from Prepare to Ship, explained below.
You're setting this on an older iPhone. iPhone 14 models and earlier have no Charge Limit. They only offer Optimized Battery Charging, under Settings > Battery > Battery Health & Charging.

iPhone 18 Pro Max only: Prepare to Ship

The iPhone 18 Pro Max battery is over 20 watt-hours, a threshold that matters for shipping rules. Apple's Prepare to Ship page explains that new units leave the factory limited to under 20 Wh, and the limit is removed when you activate the phone. 9to5Mac covered the feature when it appeared with iOS 27.

If you send a Pro Max for repair, trade it in or return it, Prepare to Ship discharges the battery and caps charging at 80% for 14 days. After that period you can turn it off:

Open Settings and tap General.
Tap Transfer or Reset iPhone.
Tap Ready to Ship.
Tap Undo Shipping Preparation.

Then check Settings > Battery > Charging and set the limit you want. Apple says you don't need Prepare to Ship for travel, and the regular iPhone 18 Pro doesn't use it.

For how the iPhone 18 Pro's battery compares with a rival, see our iPhone 18 Pro vs Pixel 11 Pro battery life comparison. If you're still choosing between the big models, our iPhone 18 Pro Max vs Galaxy S26 Ultra comparison covers the differences.

FAQ

Does an 80% charge limit reduce battery life during the day?

Yes. You start each day with less charge, so you get less runtime before the next top-up. The trade-off is lower long-term wear, which is why Apple lets you choose anywhere from 80% to 100%.

Can I set a charge limit below 80% on iPhone 18 Pro?

No. In iOS 27 the lowest option in Settings > Battery > Charging is 80%. The only other cap is the temporary one Prepare to Ship applies to the iPhone 18 Pro Max for shipping.

Is a charge limit turned on by default?

No. A new iPhone 15 or later, including the iPhone 18 Pro, starts at a 100% limit with Optimized Battery Charging on. You have to choose a lower limit yourself.