iPhone battery health: how to check it, what the numbers mean and when to replace the battery

To check iPhone battery health, open Settings, tap Battery, then tap Battery Health (on iPhone 15 and later) or Battery Health & Charging (on iPhone 14 and earlier). The main number, Maximum Capacity, shows how much charge the battery holds compared with when it was new.

Last updated November 2, 2026

The short version

Battery health is available on iPhone 6 and later, under Settings > Battery. iPhone 15 and later with iOS 17.4 or later also show the cycle count, manufacture date and first use date.
Apple says batteries in iPhone 14 and earlier are designed to keep 80 percent of their original capacity at 500 complete charge cycles, and iPhone 15 and later at 1,000 cycles, under ideal conditions.
If the battery is badly worn, the Battery Health screen says so and suggests a replacement. Apple says the message doesn't mean there's a safety issue.
Avoid heat. Apple warns that ambient temperatures above 95°F (35°C) can permanently reduce battery capacity.
iPhone 15 and later let you set a charge limit between 80 percent and 100 percent to reduce wear.

How to check iPhone battery health

Battery health is available on iPhone 6 and later. The menu name depends on your model.

iPhone 15 and later:

Open the Settings app.
Tap Battery.
Tap Battery Health.

With iOS 17.4 or later, this screen shows the battery health, maximum capacity, cycle count, when the battery was manufactured and when it was first used. It also tells you if Apple recommends a replacement. The iPhone Duo has 2 batteries, and Apple says it shows separate details for each one.

iPhone 14 and earlier:

Open the Settings app.
Tap Battery.
Tap Battery Health & Charging.

These models show maximum capacity and peak performance capability, but not the cycle count.

The main Battery screen is different. It shows battery usage: which apps used the most power today and over the past week, and when the phone was last fully charged. That tells you about battery life. Battery Health tells you about the battery itself.

What iPhone battery health means

Apple draws a line between 2 terms. Battery life is how long your iPhone runs before it needs a charge. Battery lifespan is how long the battery lasts before it needs replacing. Battery health is about lifespan.

Every iPhone uses a lithium-ion battery, and Apple calls all rechargeable batteries consumables. As they age chemically, they hold less charge and can deliver less instant power. Apple says a battery's chemical age is more than the time since it was made. It depends on the number of charge cycles, temperature history and charging patterns.

The Battery Health screen reports this in 2 ways:

Maximum Capacity is the battery's capacity compared with when it was new. A lower number can mean fewer hours of use between charges. Apple notes that a brand-new iPhone can show slightly less than 100 percent, depending on how long it sat between being made and being activated.
Peak Performance Capability tells you whether the battery can still supply the bursts of power the phone's electronics need. As a battery ages, its impedance can rise, which makes its voltage drop further under load. If it drops too far, the iPhone shuts down to protect its components.

What the Battery Health messages mean

Apple lists these messages for the Battery Health screen:

Message	What it means
Your battery is currently supporting normal peak performance.	The battery can meet normal power demands. No performance management is applied.
Performance management has been applied to help prevent this from happening again.	The iPhone had an unexpected shutdown because the battery couldn't deliver enough peak power, so iOS now limits peak performance. You can tap Disable, but Apple says you can't turn it back on yourself. It comes back automatically after another unexpected shutdown.
Your battery's health is significantly degraded.	Apple says an Apple Authorized Service Provider can replace the battery to restore full performance and capacity. Apple says the message doesn't indicate a safety issue, but you might notice more battery and performance problems.
Unable to verify this iPhone has a genuine Apple battery.	Applies to iPhone XS, XS Max, XR and later. The health information on the screen might not be accurate.

The performance management toggle in that table applies to iPhone 6 through iPhone XR. On iPhone 11 and later, Apple says a built-in system manages performance automatically and is always on. Apple adds that aging can still cause slower app launches, lower frame rates, dimmer screens or lower speaker volume on those models.

Cycle count: what's normal

A charge cycle isn't the same as plugging in once. Apple counts 1 cycle each time you use an amount of charge equal to 100 percent of the battery's capacity, not necessarily all from 1 charge. Apple's example: use 75 percent on 1 day and 25 percent the next, and the 2 days add up to 1 cycle. Apple says a complete cycle is normalized between 80 percent and 100 percent of original capacity, to allow for the battery's capacity shrinking over time.

Apple's design targets, under ideal conditions:

Model	Designed to keep	After
iPhone 14 models and earlier	80 percent of original capacity	500 complete charge cycles
iPhone 15 models and later	80 percent of original capacity	1,000 complete charge cycles

Apple says the exact percentage on any phone depends on how it's used and charged. That means 2 iPhones with the same cycle count won't necessarily show the same maximum capacity.

When to replace your iPhone battery

Apple's Battery Health screen tells you when a replacement is worth considering. The signs to look for are:

Battery Health shows the "significantly degraded" message or recommends a replacement.
Performance management has been applied after unexpected shutdowns and the slowdown bothers you. Apple says replacing the battery can help.
The battery no longer gets you through the day.

Coverage matters for cost. Apple's 1-year limited warranty covers a defective battery, but Apple says it doesn't cover batteries that wear down from normal use. With AppleCare, Apple says it replaces the battery at no extra charge if its capacity drops below 80 percent. Apple shows an estimated out-of-warranty price for your model on its battery service page.

Apple says you can take the iPhone to an Apple Store or an Apple Authorized Service Provider, or mail it to an Apple Repair Center. Shops in Apple's Independent Repair Provider program also have access to genuine Apple parts, and Apple offers Self Service Repair for some models in certain countries. Apple warns that a non-genuine replacement battery may be poorly made, used, damaged or the wrong battery for your model, and that its health readings might not be accurate.

To see whether a battery has already been replaced, open Settings, tap General, then tap About. On iPhone XR, XS and later, Apple says you'll see Genuine next to Battery if the repair used genuine Apple parts, and Unknown if the part can't be verified. On iPhone 15 and later using iOS 18, Used means the genuine battery came from another iPhone. This is worth checking before you buy a secondhand phone.

How to keep iPhone battery health high

Apple says these steps help extend battery lifespan:

Avoid heat. Apple says iPhones work best at ambient temperatures of 32°F to 95°F (0°C to 35°C), with 62°F to 72°F (16°C to 22°C) as the ideal range. Above 95°F (35°C), Apple says battery capacity can be permanently damaged, and charging in that heat damages it further. Don't charge or leave your iPhone in direct sun for long periods.
Take off certain cases when charging. If the iPhone gets hot while it charges in a case, Apple suggests removing the case first.
Leave Optimized Battery Charging on. It's on by default. It learns your routine and holds the charge at 80 percent when it expects the phone to stay plugged in for a long time, and aims to have it fully charged by the time you unplug. Apple says it needs at least 14 days and at least 9 charges of 5 hours or more in the same place before it starts working.
Set a charge limit on iPhone 15 and later. Go to Settings > Battery > Charging and pick a limit from 80 percent to 100 percent in 5 percent steps. Optimized Battery Charging is available only when the limit is 100 percent. Apple says the iPhone will still charge to 100 percent occasionally so its battery percentage stays accurate.
Store it half charged. For long-term storage, Apple recommends charging to around 50 percent, turning the iPhone off and keeping it somewhere cool and dry, below 90°F (32°C). Storing it fully drained can leave the battery unable to hold a charge, and storing it full can cost capacity.
Keep iOS updated. Apple lists updating to the latest software as its first battery tip. Our guide on how to update iPhone covers the steps.

Cold works differently. Apple says battery life drops in very cold conditions but returns to normal once the battery warms up. Apple also says unexpected shutdowns are more likely in the cold, at a low charge or with an aged battery.

Frequently asked questions

Is 80 percent iPhone battery health good?

It's the level Apple designs its batteries to keep at the end of the rated cycles, under ideal conditions: 500 for iPhone 14 and earlier, 1,000 for iPhone 15 and later. With AppleCare, Apple says it replaces the battery if capacity drops below 80 percent. Apple also notes that lower capacity can mean fewer hours of use between charges.

Is iPhone battery health accurate?

Apple says genuine Apple batteries are designed to work with iOS to report charge levels and battery health. If the screen says it can't verify a genuine Apple battery, Apple says the figures might not be accurate. Apple also released a recalibration in iOS 14.5 for iPhone 11, 11 Pro and 11 Pro Max to fix inaccurate battery health estimates on some of those phones.

Why does iPhone battery health drop so fast?

Apple says chemical age depends on charge cycles, temperature history and charging patterns. Heavy daily use adds cycles faster, and time spent hot, especially while charging, causes permanent capacity loss. Charge limits and Optimized Battery Charging reduce the time the battery spends fully charged.

Can iPhone battery health go back up?

Not on its own. Apple says maximum capacity falls as the battery chemically ages, and the fix it points to for a worn battery is a replacement, which it says restores full performance and capacity.

Why is iPhone battery health not showing?

Battery health is available on iPhone 6 and later. On iPhone X and earlier, Apple says you might see "Important Battery Message. This iPhone is unable to determine battery health." instead, which points to a battery that can't be verified. Cycle count and manufacture date appear only on iPhone 15 and later with iOS 17.4 or later.