Small-capacity VRLA battery with high temperature endurance and long lifetime

This paper describes a small-capacity, long-life valve-regulated lead-acid (VRLA) battery. The VRLA battery has the ability to endure high-temperature conditions, so it is suitable as a back-up power source for telecommunications systems outdoors as well as within office buildings. The nominal voltage of the developed VRLA battery is 12 V, and the 20 hr discharge rate capacity is from 15 AH to 65 AH. Its lifetime is more than 13 years at a floating charge voltage of 2.275 V/cell and at an average temperature of 25/spl deg/C. Thermal runaway does not occur at an ambient temperature of 75/spl deg/C or lower with a constant voltage charge. The developed VRLA battery can be used in high-temperature conditions outdoors.