Energy consumption

Mobile devices have a limited battery size, and they are not connected to a permanent power supply as with a standard computer. Therefore, an efficient usage of the battery and energy is a vital factor of survival. If you are continuously performing operations that drain the battery or require continuous access to the device hardware it will affect the user experience, and it might lead to rejection of the application.

Good energy management requires an excellent understanding of how the energy is used, and which operations can drain the battery very quickly. There are tools and benchmark frameworks to find out the energy bottlenecks and sections in the software where the energy consumption is higher than expected.

Mobile consumer-electronics devices, especially phones, are powered from batteries that are limited in size, and therefore, capacity. This implies that managing energy well is paramount in such devices. Good energy management requires a good understanding of where and how the energy is used. To this end we present a detailed analysis of the power consumption of a recent mobile phone, the Openmoko Neo Freerunner. We measure not only overall system power, but the exact breakdown of power consumption by the device's main hardware components. We present this power breakdown for micro-benchmarks as well as for a number of realistic usage scenarios. These results are validated by the overall power measurements of two other devices: the HTC Dream and Google Nexus One.