ABSTRACT
Small photovoltaic (pv) systems are normally autonomous systems and need batteries for energy storage. Up to now mainly lead-acid or nicd batteries are used. Within the described project a new type of battery, a lithium-metal battery was tested under solar operation conditions. For comparison other battery technologies (NiMH, lead-acid, RAM and Lilon) were tested too. Therefore special test regimes for parameter and cycling tests were developed. The results show that lithium-metal batteries have high efficiencies, a very good low temperature performance and high shelf life. However an optimised management system is necessary to achieve a high lifetime. The results of the battery tests were used to develop an optimized battery management system. Additionally the lithium-metal battery is optimized for solar operation. The optimized cells have a energy density of 158 Wh/kg. This parameter make them interesting for portable pv systems.
