By the Smili Phone team
Every iPhone battery is a consumable. Apple rates iPhone 14 and earlier models for about 500 full charge cycles before capacity drops to 80 percent, and iPhone 15 and later for about 1,000. After a couple of years of daily charging, some decline is completely normal. The trick is knowing when "normal aging" has become "this battery is done." Here's how to check, using your iPhone's own built-in tools.
Check Battery Health in Settings
Open Settings → Battery → Battery Health & Charging. The number that matters is Maximum Capacity: it's your battery's current capacity compared to when it was new.
- 95–100%: healthy, nothing to worry about.
- Mid-80s: noticeably weaker. You'll feel it on long days.
- Below 80%: Apple considers the battery worn. This is replacement territory.
If you see a "Service" message instead of a percentage, your iPhone has already decided: the battery's health is significantly degraded and Apple recommends replacing it.
Check the cycle count (iPhone 15 and later)
On iPhone 15 models and newer, go to Settings → General → About and look for Cycle Count. One cycle means one full 0-to-100 percent discharge, spread across however many partial charges it took. If you're deep into the hundreds, the capacity number above is no surprise.
Symptoms that confirm it
The numbers tell the story, but your daily experience confirms it. A dying iPhone battery typically:
- Drains much faster than it used to, with the same usage
- Shuts off while still showing 20 or 30 percent
- Shows "Peak Performance Capability" with performance management applied in Battery Health, meaning your iPhone is throttling itself to avoid shutdowns
- Only stays on while plugged in
- Runs warm during light use
If two or three of these sound familiar and your maximum capacity is in the 80s or lower, it's the battery, not your imagination.
Replace the battery or replace the phone?
If the iPhone otherwise works fine, a battery replacement is the obvious move. It's one of the fastest repairs we do, far cheaper than a new iPhone, and a fresh battery often makes a two-year-old phone feel new again, especially if throttling was slowing it down. A new phone starts making sense when the model is very old, the screen is cracked too, or you were already thinking of upgrading.
Not sure which camp you're in? Get a free diagnosis: mention coupon code SMILIDIAG at our Escondido shop. We'll test the battery, show you the health numbers, and give you an honest recommendation before you spend anything.
Related: 5 signs your phone battery needs replacing · repair or replace your phone?
