Electronic wrist watch - using battery providing lower voltage triggering liq. crystal indicator when battery is exhausted

摘要

In at least one of the electrodes in the battery is a small amt. of an additional, dischargeable active material (a) so that at the end of the discharge of the battery the voltage drops from one leve (V1) to a lower level (V2). The watch is also fitted with a liq. crystal indicator device which lights up or is extinguished when the lower voltage (V2) is reached. The pref. watch uses a battery contg. a negative lithium electrode (1), and a positive chromium dioxide electrode contg. an addn. (a) of 2-15%, esp. 5-10% of CFx. The liq. crystal device (b) indicates the end of the useful life of the battery.