An improved PV battery charger for low cost low power stand alone low power systems

Single dwelling solar lighting systems fulfill the much-needed gaps in rural applications in less developed geographies. Many of these systems are designed to meet challenging cost objectives, but fail to consider the reliability and availability aspects. In this paper, a simple modification to the battery charging circuit for these applications is proposed that will increase the battery life and availability and also reduce the total cost of ownership significantly. The proposed circuit uses a linear regulator with smart control algorithm to provide temperature compensation, constant voltage charging and battery overcharging protection. Efficiency of the system is also optimized.