Assisting converter based integrated battery management system for low power applications

This paper introduces a new battery management system for portable electronics applications based on the flyback converter. This new architecture integrates the voltage step-up and balancing functions inside a single converter. The step-up function is obtained using an assisting concept, where the flyback output is placed at the top of the battery pack and is therefore only processing a portion of the output power. As a result, high power processing efficiency and small converter volume are achieved. The operation of the system is regulated by a digital controller that provides voltage regulation and charge balancing of the battery cells at the same time. Experimental results obtained with 8-to-12V, 20W, 250 KHz prototype demonstrate a peak efficiency of 93.4% and show that the assisting flyback requires about 9 times smaller output capacitor than the conventional boost while maintaining approximately the same inductor volume.