The invention relates to an arrangement and a method for determining power consumption of battery powered mobile devices. According to the invention, a battery operated devices running at least one specific software application. A power measuring device is connected to a battery charging port of the battery operated device and to a computer for measuring electrical power consumed by the battery operated device over a predefined period of time. The power measuring device is communicating power consumption information to the computer, which is adapted to run a software capable of measuring the power consumed by said at least one specific software application, by deducting an idle mode power consumption from the total power drawn by the battery operated device.
