A Beginners Guide to Seiko Solar Watches


Seiko Astron GPS

Since the late 1970’s and early 1980’s solar powered watches have been providing consumers with an alternative to quartz, automatic, and manual watch movements. While early models were slightly gimmicky and sold as a niche watch to children and tech nerds, today’s solar watches are offered in a variety of styles that provide a quality that rivals or surpasses traditional watches.

Solar power watches are a bit of a misnomer, as they can be powered by any type of light including both artificial and solar.

Typically the watch dial will be opaque or will have microperforations that will allow light to be absorbed by a solar panel behind the crystal. The Photovoltaic cells then convert the light into electrical energy that powers the watch. The watch will usually store energy in a rechargeable cell to power itself when light is not available – ie: at night or when covered by a jacket or sleeve.

Seiko solar watches have been around since the introduction of the LCD Solar Alarm Chronograph A156-5000, in 1978.

For the new-comer to solar watches, the Seiko list of offerings can be a bit confusing, so let’s break it down.

  • Solar – Traditional solar powered watch with a 10 month power reserve once fully charged
  • Radio Sync Solar – Traditional solar powered watch with a six month power reserve. Is radio controlled, which means it automatically receives radio signals to precisely adjust the time and calendar
  • Solar GPS – Accurate to one second every 100,000 years thanks to the time signal it receives from the atomic clocks in each GPS satellite in orbit, the solar GPS watches receive signals even while walking or in a car. They will tell the exact time even as you move across borders and they have a perpetual calendar that will not need to be manually adjusted until February 28, 2100
  • Solar Diver – Traditional solar powered watch with a 10 month power reserve. Specially rated for scuba diving.
  • World Time Solar – Traditional solar powered watch with a six month power reserve once fully charged. Includes world time solar chronograph with power reserve indicator and world time function for 25 time zones.

Traditionally Seiko have not been leaders in the solar power watch game, with the Citizen Eco-Drive, being the most recognized name.

However, with the introduction of the Astron Solar GPS model in 2012 – resurrecting the name of the first quartz movement watch that revolutionized the Seiko name – Seiko has debuted a new and potentially game changing watch technology.

A Battery That Lasts a Lifetime?

One of the major differences between a solar watch and other types of watches is the longevity of the battery.

Various marketing posts for Seiko suggest that you would never need to change the battery of a solar watch. However, I did some digging and found a response a user received from Seiko that said:

“Regarding your inquiry, we would like to inform you that we guarantee 80% capacity for the battery for 10 years. Moreover, if you keep the watch in light almost all the time as you mentioned, its life might indeed be longer as a theoretical result; however, we do not have any practical ways to check the capacity for the storage. Thus, as a precaution, we suggest to replace the battery every 10 years.”

Ten years is still a very good life-span for a battery, considering many quartz watches will need a battery change well before that. Indeed, I found a number of users online whose Seiko solar watches were still running strong after 20 years.

The Competitive Market for Solar-Powered Watches

As mentioned, the Citizen Eco-Drive is the most direct competition for the Seiko solar watches.

The Citizen Eco-Drive offers over 300 watches ranging in price from $175 – $2,095 USD. Seiko keeps pace offering over 200 mens solar watches, and over 150 women’s solar watches, ranging in price from $195 – $6,200.

With a range of styles and a range of prices you’re going to find a Seiko solar watch that fits your eye.

Personally, here are my three favourites.

Astron SSE089

Seiko Site | Amazon Listing

  • MSRP: $1,800 USD
  • GPS Solar World Time
  • GPS controlled time and time zone adjustment (40 Time Zones)
  • Magnetic resistance 4,800A/m
  • Perpetual date calendar correct to the year 2100
  • Signal reception result indication
  • Daylight savings time function
  • Power save function
  • Sapphire glass with Seiko’s proprietary super clear, anti-reflective coating
  • Tri-fold push button release clasp
  • LumiBrite hands and markers
  • Screwdown caseback
  • Case Diameter: 45.0mm
  • Water-resistant to 10 bar, 100 meters (330 feet)
  • Caliber 8X22
  • Black Ceramic Bezel
  • Titanium Case and Bracelet with super hard black coating

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Prospex SSC509

Seiko Site | Amazon Listing

  • MSRP: $450 USD
  • World Time Solar Chronograph with Power Reserve
  • Powered by light energy
  • 6 month power reserve once fully charged
  • World time function (25 cities) with hour and minute display
  • Power reserve indicator
  • Daily alarm
  • Chronograph measures up to 24 hours in 1/5 second increments with split time measurement function
  • Date calendar
  • LumiBrite hands and markers
  • Sapphire crystal
  • Screwdown caseback
  • 42.0mm diameter
  • Water-resistant to 10 bar, 100 meters (330 feet)
  • Caliber V195
  • Leather Strap

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LeGrand Sport SNE397

Seiko Site | Amazon Listing

  • MSRP: $350 USD
  • Powered by light energy
  • 10 month power reserve once fully charged
  • Date calendar
  • Sapphire crystal
  • Screwdown caseback
  • Water-resistant to 10 bar, 100 meters (330 feet)
  • Caliber V157
  • Cabochon Crown
  • Leather Band

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