Implementation of a regenerative pulse charger using hybrid buck-boost converter

This paper presents a battery charger using the Reflex™ method. The Reflex™ method provides very high pulse current to charge the battery to reduce the charging time. In addition, this method generates negative pulse discharging current, which can relax the reaction of electrolyte and extend the life of batteries. However, the Reflex™ method generally uses a current limiting resistor, which causes loss of energy and makes the charger bulky. The paper presents a novel circuit topology for Reflex™ method. This circuit topology is composed of a two-stage converter, in which the first stage is a half-bridge converter providing a voltage source and the second stage is a bi-directional buck-boost converter. During the positive pulse charging mode operations, the buck converter supplies energy to charge the battery. During the negative pulse discharging mode operations, the boost converter transfer the energy released by the battery to a capacitor, avoiding the consumption of it. Thus, the charging time of the battery can be reduced and the efficiency of the Reflex™ charging system can be improved.