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Review of the Citizen Eco-Drive Brycen Chronograph


Review of the Citizen Eco-Drive Brycen Chronograph

Watch collectors strongly favor mechanical timepieces. If you ask us why, we lovingly describe the craftmanship required to accurately measure time using dozens of tiny mechanical gears, a rotor, and—to power it all—a tightly coiled spring.

Yet, there is another reason. Every week, I pull a new watch from my collection and strap it around my wrist, and there is nothing more disheartening than picking through a selection of great-looking timepieces, desperately hunting for one with a working battery.

Quartz watches, however, do sell very well. They are light, accurate, inexpensive, and often include cool features that cannot be incorporated into their mechanical brethren.

Today, I am taking a close look at a quartz watch that, according to its manufacture, is designed to alleviate the need to replace its battery.


The Citizen Brycen Chronograph is truly an international watch. It was designed in Japan, manufactured in China, and is powered by a capacitor fabricated in Indonesia.

This timepiece weighs in at 75 grams. It is 13.6 millimeters thick and has a circumference of 42 millimeters. This black-faced analog watch features two light gray subdials and a tiny window that displays the day of the month.

The main hands of this timepiece note the hour and minutes and record elapsed seconds when the chronograph is activated. The upper subdial records elapsed minutes. The bottom subdial keeps track of the passing seconds.

Eco-Drive watches collect natural and artificial light and then convert it to the electrical energy required to recharge the timepiece’s power cell.

Close up of Citizen Eco-Drive watch.  Note that the curved crystal distorts color and detail when photographing

Close up of Citizen Eco-Drive watch. Note that the curved crystal distorts color and detail when photographing


  • Manufacturer: Citizen
  • Name: Brycen Chronograph
  • Model: CA7027-08E
  • Crystal type: Mineral
  • Clasp type: Buckle
  • Display type: Analog
  • Case material: Stainless steel
  • Case diameter: 42 millimeters
  • Case thickness: 13.6 millimeters
  • Band: Black leather
  • Band width: 21 millimeters
  • Dial color: Black with light gray subdials
  • Bezel material: Stainless steel
  • Bezel function: Stationary; Tachymeter
  • Features: Chronograph and day of month
  • Movement: Citizen B642N Eco-Drive
  • Power cell: Panasonic MT920
  • Water resistance: 100 meters (330 feet)
Crown is flanked by two pushbuttons intended to start, stop, and reset chronograph

Crown is flanked by two pushbuttons intended to start, stop, and reset chronograph

The Manufacturer

This company is trademarked by Citizen Tokei Kabushiki Kaisha of Japan.

Visual Appeal

The Brycen Chronograph is an attractive, if somewhat understated, timepiece. The upper dial is black, with silver studs marking each hour, and includes two circular cut-outs and a small window.

A pair of subdials and a date wheel are mounted to the lower level of this sandwich-style dial. I assume that the remainder of the lower dial consists of tiny solar cells.

The case is composed of stainless steel and topped off by a rather bulbous crystal.

While I like the overall design of this watch, I feel that the effect would have been more striking if the subdials had been colored white rather than gray.

The Eco-Drive System

First introduced by Citizen in 1996, Eco-Drive watches took advantage of several technological advances that resulted in smaller power cells and longer operating times.

Solar cells are mounted beneath a translucent dial. The light captured is then converted to energy and used to power the movement and charge its battery.

According to Citizen, a fully charged power cell store can store enough energy to keep the watch running for six months.

The Movement

This timepiece is equipped with an Eco-Drive B642M movement powered by a Panasonic MT920 rechargeable capacitor.

Power Source

The Citizen Brycen Chronograph requires either natural or artificial light which is collected by a set of solar cells hidden beneath its dial. This light is converted into energy which is used to both power and charge the watch.

It is equipped with a replaceable Panasonic MT920 rechargeable capacitor. The MT920 is a manganese/lithium/titanium cell with a nominal voltage of 1.5v and a capacity of 5.0 mAh.

The Strap

A good quality black leather strap with a stainless-steel buckle nicely matches the case of this chronometer.



The Citizen CA7027-08E features a chronometer and a day of the month function. It is water-resistant for up to 100 meters.

Overall Impression

This is a well-designed timepiece manufactured by a company with an enviable reputation for quality. It is accurate, includes a very effective chronometer, and is fitted with an Eco-Drive system that removes the need for battery replacement. The Citizen CA7027-08E is recommended.

This content is accurate and true to the best of the author’s knowledge and is not meant to substitute for formal and individualized advice from a qualified professional.

© 2021 Walter Shillington