It becomes more and more popular to use electric drives using rechargeable batteries as a replacement of traditional gas engines in vehicles and tools, or as a new assistive feature in e-bikes. Due to the high cost of batteries, industry and users demand better understanding of proper usage pattern of these batteries in terms of discharging/charging cycles in order to extend batteries’ life-time. In the ongoing research project PedElEc we work towards a better understanding of the ageing processes of e-bike batteries by observing groups of users applying different usage pattern. By doing so, we learn about long-term consequences of different usage pattern and compare them with regard to battery capacity and performance. In the end, we hope to be able to give valid recommendations on how to handle batteries in e-bikes with regard to discharging-charging cycles, acceptable storage of batteries, and preferable load.

Abstract. In the developing world artisanal fishermen use kerosene lanterns for night fishing. Solar powered fishing lights became an ecologic and economic alternative to the kerosene lanterns due to the development of high efficiency LED light sources and low price solar cells. In the last years several solar fishing light systems were developed. The choice of the battery technology influences the reliability and the operating cost of the fishing light, because the battery has the lowest lifetime of all components of the fishing light.In this paper we describe the results of a battery simulation over 5 years time: The battery is daily charged by a solar module and discharged by night fishing. The meteorological irradiation data of Tanzania are used. Different battery technologies (Lead Acid, Lithium-Ion, Lithium-IronPhosphate) are tried out.The results of the simulation are the battery lifetime, cost and waste mass per year dependent on the battery technology. The study shows, that the Lithium-Iron-Phosphate technology is the best choice in terms of these factors and to the advantage of the poverty-stricken fishermen at the Victoria Lake in Tanzania and the environment.