How to check iPhone battery health (and what the number means)

iOS sums up your battery's condition in a single percentage. Here is where to find it, how to read it, and which signs matter more than the number.

Agha Ali Abbas23 September 20262 min read

Maximum Capacity compares how much charge your battery can hold today with how much it held when it was new. A phone showing 88% holds roughly 88% of its original charge, so a full battery simply runs out a little sooner than it used to.

Find your battery health

1
Open Settings.
2
Tap Battery.
3
Tap Battery Health & Charging.
On older versions of iOS this is called simply Battery Health.
4
Read Maximum Capacity.
Below it, Peak Performance Capability tells you whether iOS has started limiting performance to prevent sudden shutdowns.

What the percentage means

90% to 100%: as good as new. If battery life feels poor, the cause is usually an app or a setting, not the battery.
80% to 89%: normal wear for a phone in daily use. You may notice shorter days, especially in cold weather.
Below 80%: the battery is worn out. A replacement will make a clear difference, especially if the phone shuts down early.

How to slow down battery wear

Leave Optimized Battery Charging switched on. It learns your routine and holds the charge at 80% overnight, finishing just before you usually unplug.
On iPhone 15 and later you can set a charge limit (80% to 95%) under Settings › Battery › Charging. Staying below 100% most of the time reduces wear.
Avoid heat. Charging in direct sun, in a hot car or under a pillow ages the battery faster than anything else.
Use a certified cable and adapter. Cheap, uncertified chargers can deliver unstable power.

Messages you might see instead

If that did not work

“Service” or “Service Recommended”

The battery has worn far enough that Apple recommends replacing it. The phone keeps working until you do.

“Unknown Part” or “Important Battery Message”

iOS could not verify the battery as a genuine Apple part, usually after a third-party repair. The phone works normally, but the health figure may be hidden or inaccurate.

Frequently asked questions

Is 85% battery health bad?

No. Most iPhones fall below 90% within the first couple of years of daily use. What matters more is whether the phone still lasts the day and whether it ever shuts down unexpectedly.

Can battery health go back up?

Not really. The figure can move by a point or so as iOS recalibrates its estimate, but the battery's real capacity only goes down over time.

How many charge cycles does an iPhone battery last?

Apple designs iPhone 15 and later batteries to keep 80% of their original capacity at about 1,000 full charge cycles. Earlier models are rated for about 500 cycles.

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