Battery backup for telecom: how to integrate design, selection and maintenance

This paper explains how to reach reliable 48 V supply for telecom powering by taking step-by-step decisions. It shows the integration of design, purchase and maintenance for battery backup. The decision criteria are listed and explained. Applying these rules lead to zero-failure due to technical breakdowns since 2001. Next steps are described: 1. The two 48 V DC powering schemes explained are: single and A+B. 2. Design rules for backup application: type, installation-prescriptions and autonomy-calculation. 3. Decision criteria for purchase: technical quality, experience, warranty and installation-service. 4. Pro & Cons on different types of batteries: VRLA AGM, VRLA OPzV, GroE, and OPzS. 5. 48 V DC system-management through a self developed database on 1300 sites. 6. Standard test procedures depending on technical configuration. 7. Maintenance of all VRLA batteries with 1 yearly impedance measurement and evaluation in a self developed database. Definition of reference value and replacement criteria. 8. Data on 5-years of measurements (85.000) on over 22.000 VRLA jars (more than 693.000 Ah 48 VDC).