Patent ID: 7995920

Claim:
A system, comprising: an optical line terminal (OLT) located remotely from customer premises, said OLT included in a fiber optic communication system which permits communication via a telephone in a normal mode of operation; an optical network terminal (ONT) located at said customer premises in communication over a fiber optic cable with said (OLT); a DC power supply located at said customer premises for supplying DC electrical power to said ONT; a rechargeable battery backup unit (BBU) located at said customer premises and rechargeable by said power supply, said BBU being operatively coupled to said ONT to supply substitute DC electrical power to said ONT if and when normal electric power to said system fails; and a battery output sensor and controller located at said customer premises for monitoring output level of said battery, said sensor and controller including means for automatically signaling said ONT to go into a sleep mode to conserve power when said normal electric power fails and said output level is reduced to a first level.