You might be able to locate the OnePlus 13 even when it’s powered off

Google’s Find My Device service may have some issues, but it’s still a great tool to find your lost Android phone. It’s free, available out of the box, and has both an Android and a web client. However, it can only locate most phones when they’re powered on, as power is needed for phones to either triangulate their own location or broadcast beacons that other nearby devices can pick up on. Some phones are able to be located via Find My Device even when they’re powered off or out of battery, though, and it’s possible the OnePlus 13 may be among those devices.

The reason most Android phones aren’t able to be located via Find My Device when they’re powered off is because they stop supplying power to their Bluetooth chips when they shut down. The Bluetooth chip needs power so it can broadcast beacons to nearby devices. These beacons identify the device that’s broadcasting, which is what allows nearby hardware to tell Google approximately where your particular device is located. I’m oversimplifying how Find My Device works, of course, and I’m also leaving out some details like how it uses aggregation and encryption for better security and privacy. But I hope this helps you understand why most Android phones can’t be located when they’re powered off or out of battery.