This is accomplished on iPhone 11 and newer devices by using Power Reserve Mode, which can extend some of the iPhone’s functionality even if the device is completely depleted.
If your iPhone is linked to an Apple account with Find My connected, you can locate it for up to 24 hours after it’s turned off or for five hours in power reserve mode. If the battery charge drops to an extremely low level, the iPhone’s last location is automatically sent to Apple as a last resort. With this, Apple gives users more time to find their devices in case they have been forgotten or stolen, or if they simply need to quickly use Express Mode and get home using public transportation.
The technology behind Find My
When your iPhone drains to zero and turns off, iOS reserves a fraction of the battery to perform certain functions. Although you can’t turn on the screen and use the phone normally, the low power state turns your iPhone into something like an AirTag. This goes back to the iPhone 11’s unique Ultra Wideband chip, which provides precise location via Bluetooth Low Energy (BLE) technology.
With BLE, every time an Apple device passes near your iPhone, it pings the general location, while the Ultra Wideband chip’s spatial awareness technology provides more precise location tracking. This technology is widely supported across Apple products, starting with the iPhone 11, but you can check this list for the full extent of availability.
If you have one of these iPhones, make sure your device is connected to the Find My app. In iPhone settings, tap your name, then Find My. There, you will need to log in if necessary and then enable Find My iPhone. This ensures that your iPhone is paired with Apple’s Find My network. After that, you can open the Find My app and check that your phone is visible under the Devices tab.
