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iPhone 15 Battery Drops After Shutdown or Overnight – Quick Fix

Stop battery drain while idle with proven fixes

Symptoms

  • Battery drops 5–20% overnight
  • Battery drains while idle
  • Phone loses charge after shutdown
  • Battery falls even in Low Power Mode
  • Issue started after iOS 26 update

Common Causes

  • Background tasks running overnight
  • iOS 26 battery calibration bugs
  • Location services active in background
  • Apps refreshing overnight
  • Weak signal draining battery
  • Corrupted battery statistics

Quick Fixes

1. Restart the Device

Resets battery reporting and background processes.

2. Turn On Airplane Mode Overnight

Stops cellular and Wi-Fi drain.

3. Disable Background App Refresh

Settings → General → Background App Refresh → Off.

4. Turn Off Location Services for Most Apps

Settings → Privacy → Location Services → Set most apps to "While Using."

5. Update All Apps

App Store → Profile → Update All.

Advanced Solutions

1. Reset All Settings

Fixes corrupted battery and network preferences.

2. Update to Latest iOS

Later iOS 26 builds fix idle drain issues.

3. Check Battery Usage

Settings → Battery → Battery Usage by App. Identify apps draining power overnight.

4. Switch to LTE Instead of 5G

Weak 5G signal drains battery overnight.

FAQ

Why does my iPhone drain overnight?

Background tasks, weak signal, and location services are common causes.

Is overnight drain normal?

1–3% is normal. 10–20% indicates an issue.

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