Abstract :
By simulating real working conditions of household photovoltaic system, the effects of overcharging on lifetime of
valve-regulated lead-acid (VRLA) battery in solar home systems have been investigated; and the influences of three
kinds of charge regulator strategies on state of charge and lifetime of VRLA battery have also been studied by experiments.
A quantitative analysis of the VRLA battery behaviour under different charge regulator strategies was carried
out. It is found that the temperature compensation of the end-of-charge voltage is necessary for VRLA battery, particularly
in hot climates. The linear temperature compensation for the end-of-charge voltage keeps VRLA battery
the best state of charge compared with other charge regulator strategies. Based on our results, the design engineers
can choose a cost-effective regulator according to the details of photovoltaic system and local climate, and can estimate
working state of VRLA battery installed in a system correctly, so as to extend VRLA battery lifetime in solar home
systems. The clarification of the performance difference of VRLA battery under different regulators may be an important
issue for determining life-cycle costs and servicing requirements.
2005 Elsevier Ltd. All rights reserved.
