Reducing the cost of maintaining valve-regulated lead/acid batteries in telecommunications applications

British Telecommunications has utilized valve-regulated lead/acid (VRLA) technology for 10 years and has considerable experience of varying product performance. A discussion is given of battery applications in telecommunications and includes experiences of typical failure modes such as group-bar corrosion and premature capacity loss, together with the detrimental effects of high temperature on service life. Specific maintenance requirements are also reviewed with particular attention to costs and reliability. Data are presented on the effectiveness of new methods of testing large numbers of VRLA batteries and, in particular, the reliability of conductance testing. An explanation is given of the role of conductance measurements, discharge testing and manufacturersʹ laboratory analysis in contributing to an effective maintenance programme. Specific requirements for the management of a battery-replacement programme are also included. Finally, BT user experience is described and solutions are provided to reduce the cost of VRLA maintenance while improving reliability.