Remote data collection of VRLA batteries at BellSouth distributed power sites

An extensive battery field test program was initiated between BellSouth Telecommunications Inc. and Japan Storage Battery (JSB) to understand the actual conditions valve regulated lead-acid (VRLA) batteries are exposed to in severe remote terminal (RT) applications. JSB´s long-life VRLA battery types, PWL12V28 and PWL12V38, were installed into six remote terminal (RT) sites in Georgia and Florida along with four channel data loggers. These specific sites were selected to demonstrate worst-case conditions in terms of high ambient temperature and high solar loading. Inside and outside cabinet temperature, battery surface temperature, battery string DC current and float charge voltage was recorded every 10 seconds. The data was transmitted, via a modem, through the telephone lines to BellSouth Engineering facility in Atlanta, GA, and JSB Battery Development Center in Kyoto, Japan. Data collection began in June 2001 and continues to date. The data collection process has allowed the team to verify rectifier stability and accuracy, record ambient temperature, and record the frequency and duration of power failures at each site. This study was aimed at nonenvironmentally controlled RT enclosures. The temperature data has shown that the actual battery temperature is less than previously assumed under these conditions. Based on these findings, the team has concluded that there is a high probability that battery replacement interval may be extended from the current 4 to 5 years to more than 6 years in nonenvironmentally controlled enclosures.