Lead-Acid Battery: Reserve Batteries for Bell System Use: Design of the NewCell

For more than 100 years, lead-acid batteries have dominated the field of practical rechargeable batteries. In its modern form, the leadacid battery is derived from Faure 1 and Sellon2 who introduced the concept of a conducting lattice-like grid to provide electrical contact and mechanical containment of the particulate pastes of the positive and negative electroactive species. Despite a century of evolution which has seen this battery system optimized for automotive starting, lighting and ignition (SLI) service and become the primary industrial battery system for both stationary (communication) and traction (forklift truck, etc.) usage, modern cell designs differ only slightly from Faure's original proposals. In contrast to the deep-cycle service of industrial truck batteries, and the high-rate discharges typical of batteries for SLI usage, batteries for telephone service are continuously trickle-charged, or "floated" under conditions designed to maintain them in a full state of charge, ready for instantaneous use, should commercial power fail. Discharges are infrequent and at relatively low rates. Bell System requirements emphasize long life and high reliability in the unique float charge usemode and strive to avoid the economic penalties of excessive maintenance. 1253