Electronic timepiece battery monitoring circuit

摘要

A battery monitoring circuit wherein the voltage discharge characteristic of a battery is utilized to facilitate detection of the impending failure of a battery is provided. The electronic timepiece includes a display device for displaying time in response to timekeeping signals applied thereto and is further adapted to indicate a voltage level representative of impending failure of a battery in response to an indication signal applied thereto. The battery is adapted to deliver at least two characteristic voltage levels, the first voltage level corresponding to a first plateau of discharge, and the second voltage level corresponding to a last plateau of discharge being sustained essentially at the second voltage level for a predetermined interval of time. A battery detection circuit detects the second voltage and in response thereto produces an indication signal, and timekeeping circuitry is provided for producing timekeeping signals in response to being energized at both characteristic voltage levels of the battery.