Your iPhone isn't fully lost even when it loses power, but you must act quickly and ensure Find My is set up properly. The Find My network — a crowdsourced Bluetooth system — must be enabled separately from the core Find My feature to locate your device when offline, in Power Reserve mode, or turned off. Go to Settings > [your name] > Find My > Find My iPhone and enable both Find My iPhone and Find My network. Also turn on Send Last Location, which sends the device's position to Apple when the battery reaches a critically low level. Location Services and Bluetooth must be active, and the iPhone must have sent its location within the last seven days.

To prevent thieves from disabling tracking, disable Control Center access from the lock screen via Settings > Face ID & Passcode > Allow Access When Locked. This stops them from enabling airplane mode, though they can still power off the device.

On iPhone 11 or later (excluding SE and "e" models) with an ultra-wideband chip running iOS 15, a manually powered-off phone with battery remains findable for about 24 hours. Once the battery hits zero, compatible devices on iOS 15.2+ enter Power Reserve mode for roughly five hours, broadcasting a low-energy signal. After that, tracking is no longer possible.