Phone CleanerWhat iPhone battery health means
Every rechargeable battery holds less charge as it chemically ages. Maximum Capacity measures what your battery can hold now, relative to when it was new: at 90%, a full charge lasts roughly nine tenths as long as it did on day one, with the same use.
Chemical age is more than time. It depends on the number of charge cycles and on how the battery was treated, heat above all. A new iPhone can show slightly under 100%, depending on how long it was between being made and being activated.
How to check battery health on iPhone
- Open Settings and tap Battery.
- On iPhone 15 or later, tap Battery Health. On iPhone 14 or earlier, tap Battery Health & Charging.
- Read Maximum Capacity. On iPhone 15 or later, the same screen also shows the cycle count, when the battery was manufactured and when it was first used.
Is 80% battery health good?
80% is the figure Apple designs for. Batteries in iPhone 14 and earlier are designed to keep 80% of their original capacity after 500 complete charge cycles, and those in iPhone 15 and later after 1,000, under ideal conditions. So an iPhone that has reached 80% after a few years of daily charging is ageing as expected.
A charge cycle is 100% of the battery's capacity used, even across several days: using 75% one day and 25% the next adds up to one cycle. Topping up during the day does not cost a cycle each time.
Peak Performance Capability
The Battery Health screen also has a section for Peak Performance Capability: the battery's ability to deliver bursts of power. When all is well it reads: “Your battery is currently supporting normal peak performance.”
If an aged battery could not deliver enough power and the iPhone shut down unexpectedly, iOS applies performance management to stop it happening again, and the section says so. You might notice longer app launch times or lower frame rates. You can turn it off there, but it comes back on if another unexpected shutdown happens.
When Apple recommends a new battery
If you see Service next to Battery Health, Apple suggests replacing the battery to restore full performance and capacity, and the Battery Health screen says: “Your battery's health is significantly degraded.” Apple says this is not a safety issue and you can keep using the battery, but battery life and performance will be more noticeably affected.
Apple says the battery should be serviced by Apple or an Apple Authorized Service Provider. If the screen says it is unable to verify a genuine Apple battery, the health figures shown may not be accurate.
How to slow battery ageing
- Keep the iPhone out of the heat. Apple advises against charging it or leaving it in hot places, including direct sun, for long periods.
- Leave Optimized Battery Charging on, or on iPhone 15 or later set a Charge Limit, so the battery spends less time full.
- If you store an iPhone for a long time, leave it about half charged.
