Where to find Battery Health
Open Settings > Battery > Battery Health (on some versions, Battery Health & Charging). On iPhone 15 and newer you can also see the cycle count under Settings > General > About.
Maximum capacity
This is how much charge the battery holds compared to when it was new. Apple designs most iPhone batteries to keep about 80% after 500 full cycles, and iPhone 15 and newer models are rated for about 80% after 1,000 cycles. Once you drop below 80%, you'll usually notice the phone dying earlier in the day.
Peak performance capability
If a worn battery can't deliver enough power, the iPhone may shut down unexpectedly. iOS then turns on performance management, which slows the phone to prevent shutdowns. If you see a message about unexpected shutdowns here, a new battery usually restores full speed.
The "Service" message
"Service" or "Your battery's health is significantly degraded" means Apple recommends a replacement. The phone still works, but battery life and performance will keep getting worse.
Signs you need a new battery
- Maximum capacity is under 80%
- The phone shuts off with 20% or 30% left
- It gets warm during light use
- It only lasts a few hours away from a charger
- The screen or back is lifting, which may mean a swollen battery
Tips to make a battery last longer
Keep the phone out of the Houston heat, leave Optimized Battery Charging on, and avoid gaming while it's charging. Heat ages a battery faster than anything else.
About "genuine part" messages
On newer models, iOS may show a notice that the battery isn't a genuine Apple part after an independent replacement. The battery works normally; we'll explain this before we start so there are no surprises.
We do iPhone battery replacements while you wait in most cases. If your phone also has charging problems, see our charging port repair page.
Frequently Asked Questions
What battery health percentage is bad?
Below 80% is when Apple considers a battery worn and most people notice shorter battery life.
Does a new battery make an iPhone faster?
If performance management was active because of the old battery, yes.
How long does a battery replacement take?
Usually under an hour when the battery is in stock.
Is it safe to keep using a phone with a Service message?
Yes, unless the battery is swelling. Then stop charging it and bring it in.
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