Where to find your iPhone battery information
Your iPhone stores battery information in the Settings app, and you can reach it in about 30 seconds. Open Settings, tap Battery, then tap Battery Health & Charging. You will see two numbers: your current battery capacity as a percentage, and the peak performance capability.
The battery capacity percentage tells you how much charge your battery can hold compared to when it was new. A new iPhone shows 100%. Over time, this number drops — that is normal. The peak performance capability tells you whether your phone is running at full speed or if iOS has slowed it down to protect an aging battery.
Key Takeaways
- Battery Health & Charging is in Settings > Battery > Battery Health & Charging, and shows your current capacity as a percentage of the original.
- Capacity below 80% means your battery is aging normally; below 50% means you may notice shorter battery life between charges.
- Peak Performance Capability tells you if iOS has slowed your phone's processor to protect a weak battery.
- You can also see which apps used the most battery power in the past 24 hours or 10 days from the Battery menu.
Understanding the capacity percentage
The capacity number is the most useful piece of information on this screen. It measures how much electrical charge your battery can store right now, as a percentage of what it could store when the phone was brand new. A battery at 85% capacity still works fine for most people — it just means the battery has aged and will not hold a charge quite as long as it did on day one.
Apple considers a battery degraded when it drops below 80% capacity. At that point, you may start to notice that your phone does not last as long between charges. If your capacity is below 50%, the battery is significantly worn and you will likely see noticeably shorter battery life. At any point, you can take your iPhone to an Apple Store or an Apple Authorized Service Provider to have the battery replaced.
What peak performance capability means
Peak Performance Capability describes whether your phone is running at its normal speed. If it says "Your battery is in good condition" or "Peak Performance Capability is normal," your phone is operating at full speed. If it says something else — for example, "This iPhone has experienced an unexpected shutdown" — iOS has slowed down your processor to prevent the phone from shutting off unexpectedly when the battery is weak.
This slowdown is a protection feature, not a punishment. When a battery is old or damaged, it cannot deliver power smoothly under heavy load, which can cause the phone to shut down suddenly. iOS detects this and reduces processor speed to keep the phone running. You can turn off this slowdown in Settings > Battery > Battery Health & Charging, but doing so may cause unexpected shutdowns if your battery is weak.
Checking which apps drain your battery fastest
The Battery menu also shows you which apps used the most power. Go to Settings > Battery, and you will see a list of apps with a percentage next to each one. This percentage tells you what share of your total battery use that app consumed in the past 24 hours. Tap "Last 10 Days" at the top to see the same information over a longer period.
If one app is using an unusually high percentage — say, 40% or more — that app may have a problem or may be running in the background when you are not using it. You can force an app to close by swiping up from the bottom of the screen (or swiping down from the top right on newer iPhones) and swiping up on the app. You can also turn off background app refresh for specific apps in Settings > General > Background App Refresh.
When to consider replacing your battery
You do not need to replace your battery the moment it drops below 80%. Many people use iPhones with 70% or 60% capacity without problems. The question is whether the battery life you are getting matches what you need. If your phone lasts all day with normal use, there is no urgent reason to replace it. If you are charging it twice a day or it shuts down before the evening, a replacement makes sense.
Battery replacement costs vary by iPhone model. As of 2024, Apple charges between $69 and $99 for an out-of-warranty battery replacement, depending on your model. If your iPhone is still under warranty or covered by AppleCare+, the replacement may be covered at no cost. You can check your coverage in Settings > General > About, then look for the warranty section, or visit Apple's support page and enter your serial number.
Low Power Mode and battery settings
If your battery capacity is low but you are not ready to replace it, Low Power Mode can extend the time between charges. Turn it on in Settings > Battery > Low Power Mode, or swipe down from the top right and tap the battery icon. Low Power Mode reduces background activity, limits frame rates, and slows down some features — your phone will feel slightly less responsive, but the battery will last longer.
You can also manage charging in Settings > Battery > Battery Health & Charging. Optimized Battery Charging is on by default and learns your charging patterns, then slows down charging to 80% overnight to reduce battery aging. You can turn this off if you need your phone fully charged by a certain time, but leaving it on will help your battery last longer overall.
Frequently Asked Questions
Is 80% battery capacity bad?
No. Eighty percent is considered the threshold where battery aging becomes noticeable, but most people do not experience problems until capacity drops to 70% or lower. If your phone still lasts a full day, there is no reason to replace the battery just because it hit 80%.
Why is my battery capacity dropping so fast?
Batteries naturally degrade over time and charge cycles. If your capacity dropped 10% in a few months, that is normal aging. If it dropped 10% in a few weeks, a specific app may be draining it excessively, or the battery itself may be defective. Check which apps are using the most power and consider a replacement if the drop continues.
Can I replace my iPhone battery myself?
Apple does not sell batteries to consumers for self-replacement on most models. You can take your phone to an Apple Store, an Apple Authorized Service Provider, or certain third-party repair shops. Self-replacement risks damaging the phone and voids your warranty.
Does Low Power Mode damage my battery?
No. Low Power Mode simply reduces what your phone is doing, so the battery drains more slowly. It does not harm the battery itself. You can use it whenever you want without worry.
What does "unexpected shutdown" mean in Battery Health?
It means your phone shut down suddenly at some point, even though the battery was not completely empty. This usually happens when a weak battery cannot deliver enough power under heavy load. iOS detected this and slowed your processor to prevent future shutdowns.