An access-and-permissions audit can support battery-drain troubleshooting, but it should follow the evidence. First identify which apps or system activities used power during the problem window. Then review those apps' location, camera, microphone, nearby-device, notification, background, and network access and keep only what their current function requires. A permission grant by itself is not proof that it caused battery drain.
Start with the battery record
Capture the device model, operating-system version, battery health, test period, starting and ending charge, screen time, signal conditions, and major tasks. On iPhone, Battery settings can show usage by app and system activity, including background activity, onscreen use, notifications, and low-signal periods (Apple's battery-usage guide). Use that evidence to build a short list of apps worth auditing instead of changing every permission on the device.
Compare at least two similar periods. If an app appears only once during an unusual workload, note the context before treating it as a suspect. Also allow time for temporary post-update work to settle. The audit should explain observed activity, not force a preferred conclusion about the update, the app, or the battery.
Review permissions by app and by capability
For each app on the short list, write down its purpose and which features you actually use. Review permissions from the app view, then cross-check sensitive capabilities such as location, microphone, camera, nearby devices, contacts, photos, and notifications from the system's permission manager. Android Help documents both review paths and notes that available choices can include allowing access while the app is in use, asking every time, or not allowing access (Android permission guidance). Exact labels vary by device and operating-system version.
Check background activity, background refresh, unrestricted battery use, always-on location, and notification volume as separate controls where the platform exposes them. They are not interchangeable with permissions. For example, an app may need location while navigation is visible but not continuous background access. Record the current setting before changing it so the effect can be tested and reversed.
Apply minimum necessary access
Reduce access only when the app's current function does not justify it. Prefer a narrower choice such as while-in-use or approximate location when that still supports the feature. Do not remove a permission required for safety, accessibility, device administration, medical monitoring, navigation, or another important function without understanding the consequence. If the app lacks a workable reduced-access mode, decide whether the feature is worth the access rather than repeatedly toggling controls.
Test causation one change at a time
Change one permission or background setting, repeat the same workload and time window, and compare battery activity. Record whether the app still works and whether the measured drain changes. If several settings change together, the result cannot identify which one mattered. Restore the setting if battery use is unchanged and the restriction harms a needed function.
Close the audit with evidence
The final record should list the apps reviewed, activity that justified review, permissions before and after, business or personal need, test conditions, and result. If excessive use continues, update the app, review developer support information, or contact the device maker with timestamps and screenshots. The honest outcome may be that permissions were appropriate and battery drain came from screen time, weak signal, update processing, or battery condition instead.