EV Battery Balanced Charging using Series-Parallel Charging Architecture

In this study, we describe a battery balancing charge technology using the combined method of serial charging and selective supplementary charging to resolve the unbalanced charge problem common among battery cells for electric vehicles. In this method, the major charging is performed using serial charging while the balancing is carried out with supplementary charging. The serial component is large and heavy while the supplementary component is smaller and lighter. As an upgrade to the combined balancing, we propose a new method in which the supplementary component is replaced with a small charger which charges poorly-charged cells selectively via a time-sharing strategy. The core parts of the proposed system include a sensor array to detect the individual battery cell voltage, a duty rate control incorporating IGBTs , and a battery management system. This thesis describes experimental results which show the expected functions and performance of the proposed cell balancing architecture.