Symptoms
- Battery drops noticeably overnight or while the phone sits unused
- Screen-on time is low but total battery usage is high
- Battery percentage falls even in Airplane Mode occasionally
- Standby drain got worse after installing a new app
Likely causes
- CommonAn app waking up in the background repeatedlyPush notifications, background refresh, or location tracking can keep the phone active even while locked.
- CommonPoor cell signal causing constant reconnection attemptsIn low-signal areas the phone repeatedly searches for a network, which drains the battery even at rest.
- PossibleBackground App Refresh enabled broadlyMany apps refreshing content on a schedule adds up in standby drain.
- PossibleA pending iOS or app update running maintenance tasksPost-update indexing or optimization can temporarily raise standby drain.
- PossibleDegraded battery amplifying normal standby drainA weaker battery shows a larger percentage drop for the same actual power use.
What to do
- Go to Settings > Battery and check the breakdown of screen-on vs background usage per app.
- Identify any app with high background usage relative to how often you actually use it.
- Turn off Background App Refresh for apps that don't need to update while closed.
- Check signal strength in the areas you usually leave the phone; move to better coverage if possible.
- Turn on Low Power Mode to see if standby drain noticeably improves, which points to background activity.
- Update apps and iOS, since standby drain bugs are common after releases and often get patched.
- Restart the phone to clear any stuck background processes.
- If drain persists with no clear app cause, check Battery Health for reduced capacity.
When to call a pro
If standby drain remains severe after ruling out apps and signal, and battery health is low, a replacement is the most reliable fix.
Safety
Generally low risk
Generally low risk for a careful person. Stop if anything looks different from what this guide describes.