Lithium Batteries Provide Standby Power for Volatile Memories

Long-life battery systems are discussed in this paper as a cost effective standby power source for data retention in volatile memory systems. Continuing development of these power sources has resulted in batteries to satisfy many of the memory backup needs in the rapidly expanding microprocessor and minicomputer applications field, especially with random access memories based on CMOS and other low current technologies. Desirable battery characteristics for memory backup applications such as low self-discharge, long operating life, high energy density and reliability are discussed, as well as battery design features for lithium-iodine and other lithium cells. A comparison of various commercially available lithium and secondary power sources is presented. Important factors in battery selection are listed such as capacity ratings, shelf life and battery leakage, as well as battery application guidelines.