Energy efficient design for portable storages on battery powered computers

This thesis focuses on energy efficiency design for different storage characteristics, e. g. between an internal-storage drive of a laptop computer and a portable-storage device. It studies the characteristics of battery packs and their lifetime by observing multiple systems. Furthermore, battery discharge models have been analyzed based on system utilization in terms of CPU utilization, frequency, and voltage considering CMOS power consumption basis and using regression method analysis. The accuracy of the model is dependent on regression coefficients, the measurement techniques due to instability of battery discharge rate and capacity, and the profile workloads. The proposed models are flexible to be applied to different systems with the available or unavailable value of the present rate provided by the smart battery. They can be used to estimate the remaining battery lifetime by giving the system utilization information. By developing time series models like moving average techniques, they can be used to estimate the battery lifetime together with the present rate given by the smart battery.