Development of High-rate Discharge Stationary VRLA Battery

Abstract

NTT Facilities, Inc. has developed high-rate discharge stationary VRLA batteries (2 V, 200 Ah and 2 V, 300 Ah) for UPSs and data center backups. The battery capacities are 1.35-6.4 times greater at a discharge current of 1-3 CA compared with a conventional battery due to improved plates and poles. We reduced the masses of the batteries by 26% and the volumes by 47% for heavy-current discharges in a short time (10 minutes). In this way, the batteries were miniaturized, and the installation spaces were reduced. Moreover, the results of a life test showed that the lifetimes of the batteries can be extrapolated to more than 10 years at an ambient temperature of 25 degC and discharge currents of 2-3 CA. A vibration test showed that the batteries have earthquake-proof performance at an acceleration of 1.2 G