Mobiles & gadgets

iPhone Battery Health: What the Percentage Means and When to Replace

Find Battery Health on your iPhone, learn what Maximum Capacity and the Peak Performance messages mean, and decide whether a battery replacement is due.

By EpiFive Editorial TeamReviewed/updated 6 min readHow we check articles
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Open Settings, tap Battery, then Battery Health to see Maximum Capacity, which compares your battery with how it was when new. Apple designs iPhone 14 and earlier models to keep 80 percent of their original capacity after 500 complete charge cycles, and iPhone 15 models after 1,000 cycles, under ideal conditions. Consider a replacement when the screen says your battery's health is significantly degraded, or when the phone no longer lasts through your day.

Who this is for

This is for iPhone owners who see a percentage in Battery Health and are unsure whether it is good or bad. You will finish knowing what each number and message means, what Apple recommends, and how to decide between replacing the battery and living with it. The details below come from Apple's support page on iPhone battery and performance.

Find Battery Health

  1. Open Settings.
  2. Tap Battery.
  3. Tap Battery Health.

The screen shows Maximum Capacity as a percentage, and a status line about Peak Performance Capability. Some iPhone models show additional items on this screen, so what you see can differ by model and iOS version.

What Maximum Capacity means

Apple says Maximum Capacity measures the battery's capacity compared with when it was new. A lower capacity means fewer hours of use between charges. Apple also notes that a new iPhone may show slightly under 100 percent, depending on how long it spent between manufacture and activation, so 99 percent on a recent phone is not a fault.

The 80 percent benchmark

Apple states these design targets, assuming ideal conditions:

iPhone modelsCapacity kept after
iPhone 14 models and earlier80 percent after 500 complete charge cycles
iPhone 15 models80 percent after 1,000 complete charge cycles

A complete charge cycle means using an amount of battery equal to 100 percent of capacity, which may be spread over several partial charges. Apple adds that actual capacity depends on how the phone is used and charged, so real results vary.

How to read your number

  • Above 90 percent: the battery is in good shape and little needs doing.
  • Between 80 and 90 percent: normal ageing, and you may notice shorter days.
  • Below 80 percent: past the benchmark Apple uses; replacement becomes worth considering, especially if the phone dies early in the day.

These bands are a practical reading of Apple's 80 percent benchmark, not Apple's own categories. Apple's own trigger for service is the degraded message described next.

Peak Performance Capability messages

Apple's page lists these messages under Peak Performance Capability.

MessageWhat it means
Your battery is currently supporting normal peak performanceNothing to do
Performance management appliedThe phone had an unexpected shutdown, so performance management was turned on. The phone shows the message that performance management has been applied to help prevent this from happening again
Performance management turned offYou have manually disabled the protections. If another unexpected shutdown occurs, they are applied again
Your battery's health is significantly degradedApple says this is not a safety issue, but you may notice more battery and performance problems. An Apple Authorised Service Provider can replace the battery
Unable to verify this iPhone has a genuine Apple batteryApplies to iPhone XS, XS Max, XR and later; iPhone X and earlier show an Important Battery Message instead. The health data may be inaccurate

Apple's page lists no iPhone 16 or later rating, so for newer models check Apple's current battery page for their capacity target.

Decide: replace or keep

Reasons to replace

  • Battery Health says it is significantly degraded
  • Maximum Capacity is well below 80 percent and the phone does not last the day
  • The phone shuts down unexpectedly and the performance management message appears
  • You rely on the phone for work and cannot risk it dying

Reasons to wait

  • Maximum Capacity is above 80 percent and you are comfortable with runtime
  • The phone is about to be replaced anyway
  • The drain is recent and may come from an app or setting rather than the battery

Before replacing, check Settings, Battery for the list of apps by usage. A single misbehaving app can drain the battery quickly even when the battery itself is healthy.

Get the battery replaced

Apple says that an Apple Authorised Service Provider can replace the battery when health is significantly degraded. Apple's one-year warranty (two years in Turkiye) covers a defective battery. Outside warranty, Apple offers a battery service for a charge, but the page does not state the price, so check Apple's service options for your region on the date you plan the repair.

Before you hand over the phone

  1. Back up the iPhone to iCloud or to a computer.
  2. Follow any preparation steps the service provider gives you.
  3. Note any data you cannot afford to lose, because a service visit can involve a reset.

Choosing a repair provider

Use Apple or an Apple Authorised Service Provider. Apple says that when the phone cannot verify a genuine Apple battery, the battery health figures may be inaccurate. Apple's page does not discuss third-party repair directly.

Habits that reduce wear

Apple's page notes that actual capacity depends on how the phone is used and charged. Without inventing numbers, the sensible habits are to avoid leaving the phone in hot places such as a parked car, to avoid charging it under a pillow or in a thick case that traps heat, and to keep iOS updated because updates can include battery management changes. Apple also advises keeping the iPhone about half charged for long-term storage.

What the percentage does not tell you

Maximum Capacity is one number. It says how much charge the battery can hold compared with when it was new, but it does not say how long your day will last, because that also depends on screen use, signal strength and the apps you run. Treat the percentage and the Peak Performance Capability message together: a phone at 85 percent with the normal message and good runtime needs nothing, while a phone with the degraded message needs service whatever the number says. Apple also says the health figures may be inaccurate when the phone cannot verify a genuine Apple battery, so read the screen as a guide and not as a precise measurement. Apple adds that actual capacity depends on how the phone is used and charged, which is why two phones of the same age can show different numbers.

Troubleshooting

Battery Health is missing

Make sure you are on a supported iPhone and that iOS is updated. Restart the phone and check again.

The percentage dropped suddenly

Check again after a few days of normal use. If the percentage keeps falling fast, book a service assessment.

The phone shuts down unexpectedly

Apple's page says the performance management message appears after an unexpected shutdown caused by insufficient peak power. If you see it, or the degraded message, arrange a battery service.

If your iPhone is also running out of space, see how to free up space on Android and iPhone.

Checklist

  • Open Settings, Battery, Battery Health and note the percentage and message
  • Compare with Apple's 80 percent benchmark for your model
  • Check app battery usage before blaming the battery
  • Back up before service
  • Use Apple or an Apple Authorised Service Provider
  • Confirm the price for your region before you agree to the repair

References

Questions people ask

Where do I find Battery Health on my iPhone?

Open Settings, tap Battery, then tap Battery Health. You will see Maximum Capacity as a percentage and a message about Peak Performance Capability.

What does Maximum Capacity mean?

Apple says it measures battery capacity relative to when the battery was new. A lower figure means fewer hours of use between charges. A new iPhone may show slightly under 100 percent depending on how long it was between manufacture and activation.

At what percentage should I replace my iPhone battery?

Apple designs iPhone 14 and earlier batteries to keep 80 percent of original capacity after 500 complete charge cycles, and iPhone 15 models after 1,000 cycles, under ideal conditions. Apple recommends service when Battery Health says the battery is significantly degraded.

What does Unable to verify this iPhone has a genuine Apple battery mean?

Apple says this message applies to iPhone XS and later and that the battery health data may be inaccurate. It appears when the phone cannot verify the battery as a genuine Apple part.

iPhoneiOSBattery HealthApple
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