How to Check Your iPhone Battery Health (and What the Numbers Mean)
Battery Health is a built-in screen most people never open. Here is how to find it, what Maximum Capacity really measures, and when a number is worth acting on.
Your iPhone keeps a record of how much charge its battery can still hold compared with when it was new. It is a useful number, but it is also one of the most misunderstood figures on the device.
Where to find it
Open Settings, then Battery, then Battery Health and Charging. On most models this shows two things: Maximum Capacity as a percentage, and a line about Peak Performance Capability.
Maximum Capacity compares the battery today against a brand new one of the same type. 100% means it is still holding everything it was designed to hold. A lower number means it holds proportionally less charge, so each full charge lasts a shorter time.
What is normal
Batteries wear as they cycle, and every battery chemistry behaves this way. Losing a few percent over the first year of regular use is typical. A steeper drop is worth paying attention to, especially if it comes with sudden shutdowns or the phone feeling warm while idle.
The Peak Performance line is the more practical one. If the system reports that the battery has degraded enough that performance management may be applied, that is a real signal, not a cosmetic one.
When to act
- Sudden shutdowns while the meter still shows charge.
- Charging that stops and restarts on its own.
- Noticeably shorter daily runtime for the same habits.
- The phone getting hot during ordinary use.
If you see several of those, the battery is the place to look first. If you mostly want more runtime from the phone you already have, adding a battery case is a less invasive option than replacing the battery, and it is reversible.
