Rechargeable back-up battery system including a number of battery cells having float voltage exceeding maximum load voltage

摘要

A back-up battery system for a switching equipment load in a telephone central office wherein the back-up battery system includes one or more rechargeable batteries having cells floated at a given float voltage and of a number such that when the batteries are switched in circuit across the load, the voltage of the batteries exceeds a minimum load voltage for a preselected period, and further being of a number such that the float voltage of the batteries exceeds a maximum load voltage.