Their external power supplies — typically, little black cubes with two teeth (the plugs)-- «suck» electricity, according to the Lawrence Berkeley National Laboratory, which has measured standby power in hundreds of devices.
It measures 148.8 x75.8 x8.15 mm and is powered by a 3,000 mAh battery which the company claims can deliver up to 16 hours of talk time and 507 hours of standby time.