Symptoms
- Battery still drains quickly with Low Power Mode enabled
- Low Power Mode turns itself off unexpectedly
- No noticeable improvement compared to normal mode
- Drain continues even with the screen off and Low Power Mode active
Likely causes
- CommonA misbehaving app bypassing normal power-saving limitsA stuck or buggy app can keep using CPU or network resources despite Low Power Mode's throttling.
- CommonBattery health degraded enough that even reduced load drains fastA worn battery has less total capacity, so even efficient use still empties it quickly.
- PossibleLow Power Mode automatically disabling once charged past 80%iOS turns Low Power Mode off automatically when the battery reaches 80%, which can make it seem like it 'stopped working.'
- PossibleCellular signal issues forcing high radio power use even in Low Power ModePoor signal drains battery regardless of power mode settings.
What to do
- Confirm Low Power Mode is still on, since it turns off automatically once battery reaches 80% after charging.
- Check Settings > Battery for any single app using unusually high battery despite Low Power Mode being active.
- Force-close and check for updates on any app showing high usage.
- Check Battery Health for reduced maximum capacity, which limits how much even power-saving can help.
- Check signal strength in your usual locations, since poor signal drains battery regardless of settings.
- Restart the phone to clear any stuck background process.
- Compare battery drain per hour with Low Power Mode on versus off over similar usage to judge the real effect.
- If battery health is low, treat Low Power Mode as a partial workaround rather than a full fix.
When to call a pro
If Low Power Mode gives little benefit and battery health is under 80%, a battery replacement will likely help far more than software tweaks.
Safety
Generally low risk
Generally low risk for a careful person. Stop if anything looks different from what this guide describes.