Batteries are considered a complex technology, but their performance and capacity eventually decline in time. Even iPhone batteries will start to show signs of this as it gets older.
Once the 500 total charges mark is surpassed, it may start to drain quickly or even begin to shut down unexpectedly. With the battery health feature now available in iPhones, users can finally have "more visibility into the health of their iPhone's battery, so they can see for themselves if its condition is affecting performance".
Here are some steps on how you can check your battery health as laid out by Macworld:
- Go to Settings > Battery
- Tap on Battery Health
- You will see what the ‘maximum capacity’ of your battery is.
- Below that is an indication of the battery’s ‘Peak Performance Capacity’. If your iPhone battery is running well, you will see a message like the one below: