Microprocessor-controlled new class of optimal battery chargers for photovoltaic applications

A simple, fast and reliable technique for charging batteries by solar arrays is proposed. The operating point of a battery is carefully forced near the maximum power point of solar cells under all environmental (e.g., insolation, temperature, degradation) conditions. Optimal operation of solar arrays is achieved using the Voltage-Based Maximum Power Point Tracking (VMPPT) technique and the charger operating point is continuously adjusted by changing the charging current. An optimal solar battery charger is designed, simulated and constructed. Experimental and theoretical results are presented and analyzed. The main advantages of the proposed solar battery charger as compared with conventional ones are shorter charge time and lower cost.