Trial results, performance and economic benefits of lowered cell float potential in a working central office environment

The authors discuss results of room-temperature tests at lowered float potentials on cell and battery float characteristics. Also, they describe performance results and quantify improvements achieved in actual battery reserve time, resulting from the introduction of an additional cell into an existing -48 V DC telecommunication battery plant in a working telephone central office. Finally, they discuss the significant capacity (and hence economic) benefits resulting from the introduction of an additional cell into existing telephone battery strings (24 cells per string), without significant change in overall power plant float voltages. It is shown that battery life can be enhanced as much as 25% using low-float technology, and the capacity of a 24-cell battery string can be increased up to 25% by the addition of a 25th cell