Where to find your battery percentage and health information

Your iPhone shows your current battery percentage in the top-right corner of the screen (on older models with a home button, it appears in the status bar). That number tells you how much charge is left right now. To see deeper information about your battery's condition over time, go to Settings > Battery > Battery Health & Charging. This screen shows your battery's maximum capacity — the percentage of charge it can hold compared to when it was new.

Maximum capacity naturally declines as your battery ages. A battery at 80% capacity still works, but it drains faster than it did originally. Apple considers a battery degraded when it drops below 80%, though the phone continues to function normally. You can check this number whenever you want; it does not change from day to day unless your battery has genuinely aged.

Key Takeaways

  • Your current battery percentage appears in the top-right corner of your screen; the Battery Health screen shows how much capacity your battery has lost over time.
  • Maximum capacity naturally declines with age and use, and Apple considers 80% capacity the threshold where a battery is considered degraded.
  • The Battery Health screen also displays your phone's peak performance capability and whether it is running at full speed or throttled to protect an aging battery.
  • You can enable Low Power Mode manually or set it to turn on automatically when your battery drops to 20% or lower.
  • If your battery capacity has dropped significantly in a short time, a hardware problem may be present and a repair may be needed.

Understanding peak performance capacity

Below the maximum capacity number, you will see a section labeled Peak Performance Capability. This tells you whether your phone is running at full speed or whether iOS has slowed it down to protect an aging battery. If your battery is in good condition, it will say "Your battery is currently supporting normal peak performance." If the battery is very degraded, iOS may throttle the processor to prevent unexpected shutdowns.

Throttling happens automatically when a battery cannot deliver the power the processor demands. It is not a setting you turn on or off — it is a protection mechanism. If you see a message that your phone is running at reduced performance, it usually means your battery needs replacement. You can still use the phone normally, but demanding apps may run slower.

How to read the charging information

The Battery Health screen also shows Charging information. This section displays whether your phone is currently charging and what type of charger is connected (wired, wireless, or MagSafe). It also shows the current charge level and estimated time until fully charged.

Below that, you may see a note about Optimized Battery Charging. When this feature is on, your iPhone learns your charging habits and slows down charging to 80% overnight, then finishes the last 20% closer to when you wake up. This reduces the time your battery spends at 100% charge, which slows degradation. You can turn this feature on or off in the same Battery Health screen.

Checking battery usage by app

To see which apps are draining your battery fastest, go to Settings > Battery and scroll down to Battery Usage by App. This list shows the percentage of your total battery drain that each app has used in the last 24 hours or the last 10 days — you can switch between the two views at the top of the screen.

Apps at the top of the list are using the most power. If an app you rarely use is draining significant battery, you can uninstall it or check its settings to see if background activity is enabled. Some apps allow you to turn off background refresh or location access, which reduces their battery drain.

Using Low Power Mode to extend battery life

When your battery is running low, Low Power Mode reduces power consumption by limiting background activity, lowering screen brightness, and slowing some processor functions. You can turn it on manually by going to Settings > Battery > Low Power Mode, or you can set it to turn on automatically when your battery reaches 20% or lower.

Low Power Mode does not harm your battery or phone — it straightforward makes your charge last longer. Most people notice the difference mainly in how long the phone stays on before needing a charge. You can turn it off at any time, and it automatically turns off when you charge your phone to 80% or higher.

What to do if your battery capacity dropped suddenly

Battery capacity normally drops slowly over months and years of use. If you check your battery health and see that the maximum capacity has fallen 10% or more in just a few weeks, a hardware problem may be present. This can happen if the battery itself is defective, if the phone has been exposed to extreme heat, or if there is an internal connection issue.

In this case, you should visit an Apple Store or authorized repair center and show them the Battery Health screen. They can run diagnostics to determine whether the battery needs replacement or whether another component is failing. Battery replacement is a standard repair and is covered under AppleCare+ if you have it; otherwise, there is a cost depending on your model.

Frequently Asked Questions

Is it bad if my battery capacity is at 85%?

No. Battery capacity naturally declines with use, and 85% is still in the normal range for a phone that is a year or two old. Most people do not notice a difference in daily use until capacity drops below 70%. You can continue using your phone normally.

Does Low Power Mode damage my battery?

No. Low Power Mode straightforward reduces how much power your phone uses while it is on. It does not affect the battery itself or cause it to degrade faster. You can use it whenever you want without concern.

Why does my battery percentage jump from 20% to 0% suddenly?

This usually happens when battery capacity is very low (below 50%) and the battery cannot deliver power steadily. The phone may show an inaccurate percentage because the battery's internal resistance is high. Charging the phone fully and letting it drain completely once can recalibrate the display, though if the problem persists, the battery may need replacement.

Can I see my battery health on an older iPhone?

The Battery Health & Charging screen is available on iPhone 6 and later running iOS 11.3 or newer. If you have an older model or an older iOS version, you can still see your current battery percentage, but the detailed health information is not available. You can check what iOS version you have in Settings > General > About.