Common vessel monoblock design for sealed nickel-cadmium batteries

Abstract

A new common vessel monoblock (CVM) design has been developed for large sealed NiCd batteries. The battery is managed as one sealed monoblock unit rather than a number of individual NiCd cells. The CVM combines flooded battery cells and a CdH 2 cell (regulator) for consuming hydrogen, oxygen or both. The cells share a common gas space and the regulator is in gaseous communication with battery cells and maintained under constant voltage. A ‘smart-charged’ monitors the battery pressure, battery current, and regulator current and temperature. This battery system automatically supports the individual cell's water balance by means of water vapor transport in the common gas space. On-charge heat is produced only in the regulator and not at all in the battery cells. This condition coupled with the flooded electrolyte individual cell design and sealed battery concept, alleviates many problems associated with large sealed cell battery designs. The maintenance-free, fully automated control and fast charge capability makes the CVM battery an attractive solution for industrial and electric vehicle (EV) applications. In this paper, the design and operating principles of the CVM and test data on 100 Ah 12 V module will be discussed.