How to Check Battery Health on iPhone
Your iPhone battery doesn't last forever — and knowing exactly where it stands can help you decide whether to adjust your habits, change a setting, or consider a replacement. Apple gives you built-in tools to check this, and understanding what the numbers actually mean makes a real difference in how you interpret them.
What iPhone Battery Health Actually Measures
iPhone batteries use lithium-ion chemistry, which degrades with every charge cycle. A charge cycle is counted when you've used an amount equal to 100% of battery capacity — not necessarily one full charge from 0 to 100%. Charging from 50% to 100% twice counts as one cycle.
Apple measures battery health as Maximum Capacity — a percentage that compares your battery's current maximum charge against its original design capacity. A brand-new iPhone starts at 100%. Over time, that number drops.
Apple considers a battery in peak condition if it holds 80% or more of its original capacity. Below that threshold, most iPhones will display a recommendation for service.
How to Find Battery Health in Settings
This is the most straightforward method, available on all iPhones running iOS 11.3 or later:
- Open the Settings app
- Tap Battery
- Tap Battery Health & Charging
Here you'll see:
- Maximum Capacity — the percentage figure representing current battery health
- Peak Performance Capability — whether your battery supports normal peak performance or has been throttled to prevent unexpected shutdowns
- Optimized Battery Charging — a toggle that slows charging past 80% when your routine is predictable, which helps slow long-term degradation
If your battery has degraded significantly, this screen will show a message recommending service rather than just a number. 🔋
What the Percentage Numbers Mean in Practice
| Maximum Capacity | What It Generally Means |
|---|---|
| 100% – 95% | New or nearly new battery |
| 94% – 85% | Normal wear, good performance |
| 84% – 80% | Noticeable degradation, shorter usage between charges |
| Below 80% | Apple recommends service; throttling may be active |
These are general thresholds, not hard cutoffs. Real-world impact depends heavily on how you use your device. A battery at 82% in an iPhone used mostly for messaging may perform fine. The same reading on a device running navigation and video recording all day will feel significantly worse.
Checking Battery Health on Newer iPhones (iPhone 15 and Later)
Starting with iPhone 15, Apple updated the Battery Health screen to show capacity in milliampere-hours (mAh) alongside the percentage. This gives a more concrete figure — you can see the actual charge capacity remaining versus the original spec.
You'll also see cycle count on these models, which tells you how many complete charge cycles the battery has completed. This adds useful context: a battery at 88% with 150 cycles tells a different story than one at 88% with 600 cycles.
Using the Battery Section for Deeper Diagnostics
Beyond Maximum Capacity, the Battery section in Settings contains usage graphs that show:
- Battery level over the last 24 hours or 10 days
- Screen On vs. Screen Off usage
- Activity by app — which apps consumed the most battery in a given period
These graphs don't measure battery health directly, but they help you distinguish between a degraded battery and a healthy battery being drained by a specific app or background process. If your battery reads 91% capacity but one app is consuming an unusual share of power, that's a different problem than physical degradation.
Third-Party Apps and What They Can Actually Access
Third-party battery apps on iPhone are limited by iOS's sandboxing. They can read the same battery data exposed through Apple's APIs — capacity percentage, charge state, and sometimes cycle count on supported models — but they cannot access deeper diagnostics the way apps can on Android or macOS.
Some apps surface this data in a cleaner interface or add widgets, but they're reading the same source information as the Settings menu. If you've seen claims about apps that provide "deeper" iPhone battery analysis than Apple's own tools, treat those with skepticism. 🔍
Factors That Affect How Quickly Battery Health Drops
Understanding degradation helps you interpret your reading in context:
- Temperature exposure — Heat is the most damaging factor. Leaving your iPhone in a hot car repeatedly accelerates capacity loss more than charge cycles alone.
- Charging habits — Regularly charging to 100% and letting it sit plugged in generates heat that degrades cells. Optimized Battery Charging is designed to address this.
- Charge cycle count — Higher cycles mean more wear, but the relationship isn't perfectly linear. Usage patterns matter more than raw numbers.
- iOS version — Apple occasionally adjusts performance management behavior in software updates, which affects how the battery's state translates to real-world performance.
- Device age — Older iPhone models with older batteries may show the same percentage as a newer model but behave differently under demanding workloads.
When Battery Health Becomes a Decision Point
Knowing your Maximum Capacity percentage is only the starting point. Whether that number represents a problem — or something you can ignore — depends on your device's age, what tasks you use it for, how long you need it to last between charges, and your tolerance for carrying a charger.
A 78% battery in a two-year-old iPhone used primarily at a desk, near outlets, hits differently than the same reading in a phone that needs to last a full day away from power. The number is objective. What it means for your situation isn't.