Originally Posted by rickair7777

Some devices have been shown to continue to track location with a dead battery.

That's possible because Li batteries will be severely damaged if their charge state actually reaches zero, so they have onboard battery management. When the system tells you the battery is done and shuts down, it actually is still reserving some charge for minimal housekeeping and battery life preservation. Unless you let it it sit for weeks or maybe months, there's still stuff happening on the motherboard.

As to why a device would be designed to retain geo loc as a priority in that condition, I don't know. Maybe it can be done with very little power usage, since it's passive, receive only and requires no transmission from the device.