How to Check iPhone Battery Health (and What It Means)

Your iPhone's battery health lives in one place: Settings > Battery > Battery Health (called Battery Health & Charging on iPhone 14 and earlier), where a single "Maximum Capacity" percentage tells you how much charge your battery can still hold compared with when it was new. A newer iPhone typically reads close to 100%, and Apple considers a battery "normal" until it drops noticeably below that; once it falls under roughly 80%, you may see a "Service" notice, and if you have AppleCare+, Apple will replace the battery for free. Here's exactly how to check it, what each number means, and what to do once you know your result.

Where to Find Battery Health on Your iPhone

The exact screen name and location depend on which iPhone you own, but the path always starts in the same place:

• iPhone 15 and later (iOS 17.4 or later): Open Settings, tap Battery, then tap Battery Health.
• iPhone 11, 12, 13, or 14: Open Settings, tap Battery, then tap Battery Health & Charging.
• iPhone Duo (dual-battery models): Each cell gets its own cycle count and capacity figure listed on the same screen.

Apple documents the exact wording and layout for each generation in its own support article on iPhone battery and performance, which is worth bookmarking since the screen's name and the controls underneath it (Optimized Battery Charging, Charge Limit, Clean Energy Charging) have changed slightly with each major iOS release. On that screen you'll see your Maximum Capacity percentage and, depending on your model, a note about Peak Performance Capability.

If your iPhone doesn't charge reliably in the first place, it's worth ruling out a cable, port, or software issue before you read too much into the battery health number — this guide to why an iPhone won't charge and how to fix it walks through the usual culprits, since a bad cable can look a lot like a failing battery at first glance.

What "Maximum Capacity" Actually Measures

Maximum Capacity is a measurement of your battery's current ability to hold charge relative to when it was brand new. A reading of 100% means the battery still has essentially its full original design capacity; a reading of 85% means it can now hold about 85% of the charge it could when you first used your iPhone. Apple doesn't publish the exact algorithm, and the figure shifts gradually as the lithium-ion cell chemically ages — a normal, expected process for any lithium-ion battery, the same technology used in laptops and electric vehicles.

Because the number reflects the physical condition of the battery cell rather than anything stored in software, actions like erasing your iPhone or restoring it from a backup do not reset or change your Maximum Capacity reading. Only time, charge cycles, and heat exposure move that number — which is why a factory reset won't "fix" a degraded battery or make the percentage climb back up.

What a "Charge Cycle" Actually Counts

A charge cycle is completed every time you use an amount of battery power equal to 100% of capacity — whether that happens in one full charge from 0 to 100%, or added up across several partial top-ups (for example, two days of charging from 50% to 100%). Apple's own cycle count is normalized to the battery's current capacity, measured between 80% and 100% of the original capacity, and on dual-battery iPhones each cell tracks its own count separately.

Cycle count matters because it's the main variable behind Apple's own degradation targets. According to Apple, iPhone batteries are designed to retain 80% of their original capacity at a specific number of complete charge cycles under ideal conditions:

In practice, most people rack up roughly one cycle every one to three days depending on how heavily they use their phone, which is why visible battery wear usually doesn't show up until the second year of ownership.

Normal vs. Degraded: What the Percentage Actually Tells You

There's no single official cutoff where Apple labels a battery "degraded" versus "normal," but the Battery Health screen itself gives you the clearest signal. A battery in the high-90s to 100% range is behaving like new. Low-to-mid 90s is still considered normal wear for a phone that's a year or more old. Once the Maximum Capacity figure drops far enough that Apple's own software flags it, the screen will show a note that the battery's health is significantly degraded, often alongside a recommendation to have it serviced.

A related but separate indicator is Peak Performance Capability. This note appears if your iPhone has unexpectedly shut down because an aged battery couldn't deliver enough peak power, and iOS has applied limited, dynamic performance management to prevent further shutdowns. Seeing this message is a stronger signal to get the battery checked than the Maximum Capacity percentage alone, since it means the battery has already affected real-world performance rather than just aging on paper.

When Apple Replaces Your Battery Free vs. What You'll Pay

Whether a replacement costs anything comes down to what coverage is attached to your iPhone, not just the Maximum Capacity number by itself:

• Apple's one-year limited warranty covers a battery only if it's defective — it explicitly does not cover batteries that have simply worn down from normal use.
• AppleCare+ adds a specific battery-wear benefit on top of accidental-damage coverage: Apple will replace the battery at no extra charge once its capacity drops below 80% of original, for as long as the plan is active.
• Without AppleCare+ and outside the one-year warranty, a worn battery is treated as an out-of-warranty repair. Apple inspects the device first and gives you a final service fee before doing the work; a shipping fee may apply if you mail it in, and Apple Authorized Service Providers set and quote their own prices.

Apple also guarantees its own repairs and genuine replacement parts for 90 days, or for the rest of your original warranty term if that's longer. You can start a request, check current pricing for your exact model, or book an appointment at a Genius Bar or Apple Authorized Service Provider directly through Apple's iPhone battery service and repair page; mail-in service with a prepaid box is also available without an in-person visit, and you can track a repair afterward in the Apple Support app.

Tips to Slow Battery Wear

Apple publishes its own guidance on prolonging battery lifespan in a dedicated battery life and lifespan page, and the advice there focuses on two levers: reducing time spent at full charge, and avoiding heat, since both accelerate the chemical aging that lowers Maximum Capacity over time.

• Leave Optimized Battery Charging on. Available since iOS 13, it reduces the time your iPhone spends sitting at 100% by using on-device machine learning to delay the final part of a charge until closer to when you typically unplug, based on at least two weeks of learning your routine. Apple's own documentation on Charge Limit and Optimized Battery Charging warns that turning this feature off "can increase wear on your battery and reduce its lifespan."
• Use Charge Limit if your iPhone supports it. On iPhone 15 and later, Settings > Battery > Charging lets you cap charging anywhere from 80% to 100% in 5% steps, which further limits time spent at full charge; iOS will still top up to 100% occasionally to keep its capacity estimate accurate.
• Take the case off if your iPhone gets hot while charging. Some cases trap heat, and excess heat during charging can affect long-term capacity.
• Avoid extreme ambient temperatures. Apple's ideal operating range is roughly 62°–72°F (16°–22°C); it recommends avoiding temperatures above 95°F (35°C) and not charging a device that's already hot.
• Keep iOS up to date. Software updates can include energy-efficiency improvements that reduce overall battery demand, on top of any security fixes.
• Storing an iPhone long-term? Charge it to around 50%, power it off, and keep it somewhere cool and dry below 90°F (32°C) — never store it fully charged or fully drained for months at a time, and give it about 20 minutes of charging before first use if it's been stored longer than six months.

None of these tips will raise a Maximum Capacity number that's already dropped — degradation is one-directional — but together they slow how quickly a healthy battery ages in the first place, which is the only lever you actually control day to day.

How This Differs from Checking Battery Health on Android

iPhone has one consistent, built-in Battery Health screen across every supported model, maintained by Apple and showing the same Maximum Capacity and Peak Performance Capability concepts regardless of carrier. Android doesn't work the same way: because Android is licensed to many manufacturers, there's no single universal "Battery Health" menu that looks the same on every device. Pixel and Samsung Galaxy phones each expose battery-wear information differently, and on some Android phones you need a carrier or manufacturer app rather than a stock Settings menu entry at all. If you're comparing a Pixel or Galaxy phone against an iPhone, this breakdown of how to check battery health on Android, Pixel, and Samsung Galaxy phones covers where each manufacturer hides the equivalent setting.

A Few Things That Trip People Up

"My battery health looks fine, but my phone still feels sluggish or dies fast." Maximum Capacity isn't the only thing driving battery life. Background app activity, a poor cellular or Wi-Fi signal, an outdated iOS version, or simply having too many apps refreshing in the background can all make a phone feel like it has a battery problem when the battery itself is fine. It's worth working through the basics before assuming the cell is at fault.

"I erased my iPhone and the percentage didn't change." That's expected. Maximum Capacity tracks the physical battery's chemical age and charge-cycle history, not anything stored in your data or settings, so Erase All Content and Settings or a fresh restore doesn't recalculate or reset it.

"Is it worth replacing the battery or just getting a new iPhone?" That depends on the rest of the phone's condition and how the out-of-warranty service fee compares with the cost of upgrading, since Apple doesn't publish a single flat price — it quotes one after inspecting your specific model and region. If you do decide to move to a new iPhone instead of servicing the old one, Apple's own migration tools make the switch straightforward; see this walkthrough on transferring data to a new iPhone with iCloud, Quick Start, or from Android for the setup steps.

What to Do Next

Open Settings > Battery and tap into Battery Health (or Battery Health & Charging on older models) to see where you actually stand. If Maximum Capacity is in the high 90s, there's nothing to do — keep Optimized Battery Charging on and move on with your day. If it's noticeably lower, or you see a Peak Performance Capability or "Service" note, check whether AppleCare+ is active on the device; if the capacity is under 80% and your plan is still valid, a replacement costs nothing. If you're out of coverage, get an inspection-based quote through Apple's support site or an Apple Authorized Service Provider before deciding whether to repair or replace the phone, and in the meantime, dial in the charging habits above to keep the number from sliding further.

Written byNadia Osei

Nadia Osei covers mobile and consumer gadgets for Pandromeda: smartphones, tablets, smartwatches, earbuds and smart-home devices. She tracks launches, software updates and pricing across Apple, Google, Samsung and the rest, and builds comparisons from the manufacturers' published specifications.

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