Open Settings > Battery before deleting apps. Compare the daily chart, app and system activity, update insights, signal conditions, and the battery-health service message.
A fast drop is only diagnosable when it is compared with what the phone did. Open Settings > Battery and use Apple’s usage chart and insights before uninstalling apps or resetting the phone.
Check for temporary post-update work
After an iOS update or new-device setup, indexing, downloads, and restoration can continue in the background. Battery settings may show Ongoing iOS Update or Ongoing Device Setup. Keep the phone on reliable Wi-Fi and power when practical, then compare again after the work finishes instead of erasing it on the first day.
Read the usage details
Tap View All Battery Usage and select a day. The details can identify background activity, weak or absent cellular coverage, and notifications that repeatedly wake the phone. A high percentage is not automatically suspicious if you actively used that app for hours.
Address the measured cause: reduce unnecessary background location for the listed app, adjust excessive notifications, or use a strong Wi-Fi signal where available. Low Power Mode is useful when charge is limited, but it also reduces features such as background refresh and some visual effects.
Check battery health rather than guessing
In Battery settings, open the battery-health panel shown for your model. Rechargeable batteries age and may eventually need replacement. If iOS displays Service, follow the service guidance. Maximum-capacity percentage alone does not predict every person’s runtime because display brightness, radio signal, and workload differ.
Confirm the result
Compare two similar days, not a heavy travel day with an idle day. If the phone loses large amounts of charge while unused, remains hot at rest, shuts down unexpectedly, or the battery is swollen, stop relying on software tweaks and obtain Apple diagnostics. Save screenshots of the daily chart without exposing private notification content.
Primary sources
Interfaces and policies change. We recheck the steps above against these sources and show the verification date at the top of the guide.