As we knew iOS 8 includes a number of new features, improvements, and changes. Find My iPhone (iPad,iPod) service has also received a new functionality, allowing users from iOS devices to enable a "Send Last Location" option, that will send to Apple iPhone's last known location when the battery drains to a critical level.
The current Find My iPhone in iOS 7 cannot determine the last location of a device when its battery is drained, just iCloud will display the last location for up to 24 hours.
If Find My iPhone can’t locate a device, the last known location is displayed for up to 24 hours. Select “Notify me when found” to get an email when it comes online.Now you can know iPhone's last known location if its battery is drained, that would done through Apple, when you enable the setting, you authorize Apple to store the last known location of your device. To get that information potentially you have to contact the company, after it is no longer available on iCloud.
Find My iPhone is known improvements in every new iOS version, in iOS 7 Find My iPhone has brought Activation Lock feature, which prevent anyone to reactivate your iPhone without your own Apple ID and password, the feature is enabled automatically when you turn Find My iPhone on. It has contributed well in reduction of iPhone's robberies in many major cities.