Extending the reliability of DC power in a telecommunications network

To maintain continuity of service of any telecommunications network it is necessary to provide some form of back-up power to cater for uncertainty of the public utility supply. The growing use of smaller and more remote sites associated with cellular networks and optical fibre networks really demands a compact dependable source of DC power, with minimal maintenance costs, capable of extending the back-up cover afforded by small battery installations. Engine alternator sets particularly when infrequently used and lightly loaded, often do not provide the desired level of reliability. One option that has been developed to meet this need is the aluminium-air fuel cell. Applications ranging from a few hundred watts supply required for cellular transceiver stations to a study for a 20 kW system for a major network operation are described