Use of LiFePO4 Batteries in Stand-Alone Solar System

In this paper the use of lithium iron phosphate (LiFePO4) batteries for stand-alone photovoltaic (PV) applications is discussed. The advantages of these batteries are that they are environment-friendly, provide high safety, show long cycle life and hence relatively low lifetime costs. Different characteristics of batteries from various manufacturers have been studied in several battery testing experiments. Among the investigated properties are the relations of capacity, state of charge (SOC) and end-of-charge voltage as well as different charge-discharge durations. Differences between the capacities specified by manufacturers and the ones actually reached in experiments are reported. The tests show that LiFePO4 batteries are an ideal choice for stand-alone PV systems due to their high efficiencies and long cycle life, provided that they are operated with a charge control algorithm specifically targeted for long charge durations as they are typical in solar PV applications. (C) 2012 Published by Elsevier Ltd. Selection and/or peer-review under responsibility of APVIA.