Fully Insulated Dual Output DC-DC Converter Battery Charging System with Single Dynamo Input at the Electric Vehicle

Battery charging and regulation for the electrical system of electric cars or fuel cars are of great importance for the efficient operation and comfort of the vehicles. In this study, a DC-DC boost converter system that can charge two batteries isolated from each other with the same dynamo for a car is presented. With this system, it is possible to charge two different batteries at their nominal voltages at the same time by increasing the voltage of the system at the low voltage inputs that will occur. First, the circuit model and mathematical expansions that give the operating logic of the circuit are given. Then, the designed circuit model is operated between the modulation indexes of 0.2-0.5 and two different batteries are fed at their nominal voltages in isolation from each other. After the simulation studies, the current and voltage values of the circuit elements and the charging parameters of the battery are measured and the system application is carried out. According to the obtained results, although the charging circuit receives low voltage from the alternator, the two batteries can be charged to the requested level with the proposed system. © 2025, Strojarski Facultet. All rights reserved.