Are solar watches worth it? Yes, and for a reason most reviews do not mention

The straight answer

On this site solar is the single highest-weighted thing a watch can have, so you should expect us to say yes. What is worth your time is why, because the usual reason given, "you never buy a battery", is the least interesting benefit and the easiest to dismiss. A coin cell costs almost nothing and lasts years.

The real answer has two parts. On a quartz watch, solar converts an appointment into nothing: no battery change, no case opening, no reseal, no risk of a bad gasket job. On a GPS watch, solar does something different and more valuable: it keeps a sealed, non-replaceable lithium cell from being cycled, and cycle count is what kills rechargeable electronics.

Two completely different things called solar

These get lumped together constantly and they are not the same product.

Solar as the whole power system. Casio Tough Solar, Citizen Eco-Drive, the Epson solar movement in a Bertucci, the solar movement in a Timex Expedition North. The watch has a solar cell and a rechargeable secondary cell and never meets a charger in its life. Citizen states its Eco-Drive is powered by any light source with no battery replacement. This is the version that is unambiguously worth it.

Solar as a top-up on a rechargeable watch. Garmin's Power Glass lens, Suunto's solar Vertical. The watch still has a USB or magnetic charger in the box, and the solar lens extends the interval between charges, sometimes to the point where Garmin writes the word "unlimited" in its own battery table. This version is worth it for the cycle-count reason rather than the convenience reason.

What the makers publish

No maker publishes a lifespan in years for a watch or a cell, and neither do we. What they do publish is how long the watch runs with no light at all, which is the honest measure of whether solar is a real power system or a decoration:

Two things to take from that table. First, the Casio figures are months in a drawer, which is the worst case; worn outdoors, those watches simply never run down. Second, Garmin's condition is three hours a day at 50,000 lux, which is a bright overcast day and not desert noon, so the unlimited claim is achievable for anyone who is actually outdoors. The detail on that is in Garmin solar explained.

The real argument: charge cycles

Here is the part that decides whether a watch is worth owning in ten years, and it is the reason this site weights power at 25%.

A rechargeable lithium cell degrades with charge cycles. A GPS watch that you plug in weekly takes roughly fifty cycles a year; an AMOLED watch charged every two days takes closer to a hundred and fifty. A solar GPS watch worn outdoors might take five. Same cell chemistry, same watch, an order of magnitude difference in how fast the power system ages, and in a sealed outdoor watch the cell is not a part you swap on a Saturday.

That is why an Instinct 3 Solar and an Instinct 3 AMOLED are not the same purchase even though the case is nearly identical: Garmin's AMOLED table gives up to 24 days by gesture or 9 days always-on, against an unlimited-with-solar claim on the Solar model. The comparison is in Instinct 3 solar vs AMOLED.

When solar is not worth it

Three honest cases, because a guide that says yes to everything is useless.

1. The watch lives indoors. Solar cells need light, and a watch worn under a long sleeve in an office, then put in a drawer overnight, may never reach a full charge. Casio's dark-running figures are months, so it will still work, but you are paying a premium for a feature you are not using. A coin-cell G-Shock with a five-year cell is the better buy, and the cheap end of that is best G-Shock under $100.

2. You want the absolute minimum you can spend. Solar is the single feature that separates the cheapest G-Shock tier from the next one up. If the budget is the binding constraint, a DW-5600E on a CR2016 Casio rates at about five years is an honest watch that will outlast most things you own. The tier-by-tier version, with each list price sourced, is best G-Shock under $200.

3. You would rather have no battery at all. A mechanical watch has a mainspring, not a cell: nothing to charge, nothing to replace on a schedule, and a watchmaker service as the running cost instead. It drifts seconds a day and needs winding or daily wear. That is a legitimate different answer and it is argued out in solar vs automatic watch.

The picks

The verdict

If the answer is yes for you, the practical follow-up is how much light the watch really needs and where to keep it when you take it off: how to charge a solar watch.