Selecting batteries for uninterruptible power supply systems

The authors emphasize the importance of examining battery performance at the uninterruptible power supply (UPS) design points rather than relying on the battery nameplate rating which is obtained at much lower discharge rates than those of interest to UPS designers. The authors examine some specific aspects of the electrical performance needed for UPS batteries. Batteries designed specifically for high-rate UPS applications offer a 60% improvement in volumetric energy density over comparable traditional batteries. In addition to enhanced performance, batteries designed specifically for UPS applications also possess other operational advantages that permit creative UPS design and make systems more attractive to their users. The authors address three major areas of concern for distributed UPS systems: (1) compatibility with existing racking and cabinetry, (2) compatibility with the surrounding environment (especially important for office applications), and (3) reduction or elimination of routine maintenance