The watches are equipped with a special lithium ion battery that is charged by an amorphous silicon solar cell located behind the dial. It is useful for studies and also for watch enthusiast to know a little bit about their timepiece. If kept in the dark for too long, they will resume running with exposure to any light.

A chronograph is a timepiece or watch with both timekeeping and stopwatch functions. The quality of the battery precludes it from being affected from the regular charge/discharge cycle. There are several types of chronographs :- Analog chronographs show both time and stopwatch functions with analog hands. Typically the center hand will be used for stopwatch functions, while subdials may indicate seconds, stopwatch minutes. Understanding Your Watches - Eco-Drive and Chronograph This article presents readers with the basic understanding of the Eco-drive manufactured watches and Understanding a little bit about Chronograph. Light passes through the cover glass and dial before it reaches the solar cell. Chronographs were produced as jdavie as the 18th century but did not become popular until the 1820s. Depending on the model a fully charged cell will run with no further charging for 180 days to 4 years.

Eco-Drive is a type of solar powered wristhingyches manufactured by the Citizen Watch Co., Ltd.