2004 update long-term study - VRLA battery life at BellSouth remote terminal sites

A joint team formed by BellSouth Telecommunications Inc, GS Battery (USA), and Japan Storage Battery (JSB), initiated a long-term battery performance study in 2001 using JSB's PWL series valve regulated lead acid (VRLA) battery. Data was collected and analyzed in order to understand the impact of actual telecom outside plant (OSP) conditions on VRLA batteries. The study began in March 2001 and continues to present. Initial findings were presented at INTELEC 2002 in Montreal. This paper will update those findings and provide the status of the study. JSB's long life VRLA batteries are installed at 10 BellSouth Remote Terminal sites in Georgia, Louisiana, and Florida. Data are collected at each RT site via a 4-channel data logger. The team selected these sites as representative of worst case in terms of high ambient temperature, solar loading, and effects of legacy power systems. Data recorded included: 1. Internal cabinet temperature. 2. Battery surface temperature. 3. DC string current. 4. DC string voltage. The initial findings presented at INTELEC 2002 remain valid: The battery replacement period for JSB's long life VRLA batteries may be extended by an additional 1-2 years. As validation, test batteries were removed from selected sites for residual capacity measurement, and for analysis of degradation to the active materials. The data continues to support the conclusion that the current BellSouth battery replacement interval may be extended, thus reducing battery replacement costs.