Menu
What You Need Before You Start
Checking your iPhone battery health requires no additional tools or apps. The feature is built into iOS. You only need:
- An iPhone running a recent version of iOS.
- The device’s passcode, if you have not recently unlocked it.
- A few minutes to navigate the Settings app.
The battery health reading you will see is an estimate provided by the device’s internal management system. It is not a laboratory measurement, but it is the most reliable indicator available to the average user.
How to Check iPhone Battery Health
-
Unlock your iPhone and open the Settings app.
-
Scroll down and tap Battery.
-
Tap Battery Health & Charging.
On this screen, you will see the Maximum Capacity percentage. This number represents your battery’s current charge capacity relative to when it was new. A new iPhone battery starts at 100%. As the battery chemically ages, this percentage decreases.
-
Below the percentage, note the Peak Performance Capability message. This tells you whether the battery can support normal peak performance.
- Your battery is currently supporting normal peak performance. This is the ideal status. The battery can deliver the necessary power without unexpected shutdowns.
- This iPhone has unexpectedly shut down because the battery was unable to deliver the necessary peak power. This indicates a performance management feature has been applied to prevent further shutdowns. The device may reduce performance in some situations.
- Your battery’s health is significantly degraded. This appears when the battery’s chemistry has deteriorated to a point where it is not safe or reliable.
- Unable to verify this iPhone has a genuine Apple battery. This message appears if the device cannot confirm the battery was installed by an Apple Authorized Service Provider. Performance and health reporting may be affected.
-
Review the Charging Optimization settings on the same page. While not a health check itself, this section shows you your current charging behavior settings (Optimized Battery Charging, 80% Limit, or None). Using these features can help slow the battery’s aging process over time.
Understanding the Maximum Capacity Reading
The Maximum Capacity percentage is a useful guide, but it is important to understand its limitations.
- It is an estimate. The number is calculated by the battery’s internal management system and can fluctuate slightly.
- It does not predict exact runtime. Two iPhones with 89% capacity can show different real-world battery life depending on apps, settings, and usage habits.
- A drop below 80% is significant. Apple considers a battery to be consumed when it has reached 80% of its original capacity. If your iPhone is within the AppleCare+ service period, Apple will service the battery at no charge once it falls below 80% capacity.
- The reading may be unavailable. If you have a battery warning, a high temperature message, or if the device has recently been shipped or used in extreme conditions, the capacity reading may be temporarily unavailable.
When to Replace Your Battery
There is no single number that forces a battery replacement. Consider replacing the battery if:
- The Maximum Capacity is below 80%.
- You see the “Significantly degraded” warning.
- Your iPhone unexpectedly shuts down under normal load.
- You notice a significant decrease in screen-on time compared to when the device was new.
- Apps take noticeably longer to launch or animations appear sluggish, especially when the Peak Performance Capability message indicates performance management is active.
- You plan to keep the device for another year or longer.
Alternative Methods and Third-Party Tools
The built-in Battery Health section is the only method Apple officially supports for checking battery health without specialized hardware.
- Third-party apps: Many apps claim to read battery information, but on modern iPhones, iOS restricts what third-party apps can access. Most third-party battery apps can only read data that the system already reports, meaning they rarely provide information beyond what you see in Settings. Some may require a computer connection or a setup process that is not straightforward.
- Mac or PC: You can connect your iPhone to a computer and use a desktop application like CoconutBattery (on a Mac) or iMazing (on Mac and Windows) to view more detailed battery statistics, including cycle count and design capacity. These tools can be more useful than the iPhone’s built-in display for long-term battery tracking.
Common Problems
The Battery Health section is missing or greyed out. This can happen if the device is very cold or very hot, or if it cannot communicate properly with the battery. Move the device to a room-temperature environment and wait a few minutes. If the section remains unavailable, a hardware issue may be present.
The percentage does not change. Battery capacity does not decrease in a straight line. It may stay at a certain percentage for weeks or months and then drop a point or two. This is normal.
The percentage suddenly dropped. A single large drop (for example, from 94% to 90%) can occur after a full charge cycle that recalibrates the estimate. It is not necessarily a sign of a defective battery, but if you notice a sudden drop accompanied by poor battery life or shutdowns, the battery may need service.
The Peak Performance Capability message changes. The performance management system can turn on or off automatically based on a single unexpected shutdown event. If you see the message about an unexpected shutdown, and you have not had any shutdowns recently, the system may have logged an event from a previous occurrence.
Conclusion
Checking your iPhone battery health is a simple, built-in process accessible through the Settings app. The Maximum Capacity percentage and Peak Performance Capability message are the key indicators to monitor. When capacity falls below 80% or the device begins to experience unexpected shutdowns, a battery replacement is the most practical solution.
Frequently Asked Questions
Should I always let my iPhone battery drain to 0% before charging?
No. Lithium-ion batteries used in iPhones do not benefit from deep discharges. Frequent partial charges are better for long-term battery health.
Does fast charging damage the battery?
Fast charging generates more heat, which can accelerate battery aging. Using Optimized Battery Charging can help, but regular fast charging may lead to slightly faster capacity loss compared to standard charging.
How long does an iPhone battery typically last?
Battery lifespan varies significantly with usage and environment. Most iPhone batteries are designed to retain up to 80% of their original capacity for 500 complete charge cycles. Heavy users or those who frequently charge in hot conditions may need a replacement sooner.
Can I replace the battery myself?
It is technically possible, but it requires specialized tools and careful procedure. Apple strongly recommends using an Apple Store or Apple Authorized Service Provider. If an unauthorized replacement is performed, the device may show a warning message about an unrecognized battery, and some health reporting features may be disabled.
