Battery types being investigated for use to provide backup power for communications sites

Traditional large telephone companies have used flooded lead-acid batteries for backup in their main central office (CO) sites. In their outside plant (OSP) electronic equipment locations, they have primarily used VRLA batteries. In the last few years, NiCd and lithium-based batteries have made inroads into the OSP. Li-ion and NMH batteries are now being considered for use in the COs. This paper explores the reasons for looking at the more expensive (initial cost) alternatives, and what the future might hold for use of alternative technologies as well as existing technologies.