They’re inflated number for real-world use, but years ago I did a pointless experiment with some friends where we posted a Motorola Android phone to each other to ‘map’ the postal network. The phone was packaged up with everything that could be turn off, only GPRS data enabled and took GPS reading once a minute (or every five minutes when stationary) and posted them to a web server. Even after two weeks it had well over 50% of its battery left.