Design and optimization of supercapacitor hybrid architecture for power supply-connected batteries lifetime enhancement

Abstract

AC power adapters for battery-operated systems, such as smartphones and notebook computers, not only supply run-time power to operate the devices but also charge the built-in batteries. The capacity of the adapter is optimized for the average power demand rather than the maximum power demand to reduce the size and weight of the adapter. Such a reduced capacity adapter may cause the battery to age even when the device is operated with the power adapter while under higher power demand, which is different from the expectation of most users. A recent study proposed a supercapacitor assist architecture to reduce the battery aging when the battery is powered by the adapter. However, the previous work only shows the potential of the architecture. In this work, we propose a design methodology to find the optimal setup for the supercapacitor hybrid architecture considering supercapacitor array structure and power conversion efficiency. The results show that a supercapacitor having 17.5 mF capacity and 20 V withstand voltage is enough to supply the deficient energy of a reduced capacity power adapter.