Casio WS210H is possibly the best cheap solar digital watch

What's the big deal with solar?

The big deal is that as long as the watch isn't shoved in a drawer (meaning not put in total darkness for extended periods of time,) it is totally possible for the battery to last 15 to 20 years.

In the photo at the beginning of this, note the PS at the bottom left of the display. That means Power Save, which is an option you can have enabled or disabled. It makes no sense to ever disable this. Turn PS on and leave it on. What this does is that if the watch is in the dark for long enough, the display turns off...

...which is exactly how I received this watch new. When I took it out of the box, the display was blank. But as soon as it detected light, the display came right back on. The way it works is that if the watch is in the dark for an hour, the display turns off but all other functions remain enabled (like the alarm and hourly signal.) If you leave it in the dark for over a week, the beep and night light are auto-disabled until the battery gets a proper charge again.

How to know the state of the battery charge is seen easily at the right of the display. H is high, M is medium, L is low.

But again, as long as PS is kept enabled and the watch isn't put in total darkness for extended periods of time, it is highly unlikely the charge will ever move from H.

Do other solar watches act the same?

Basically, yes. Any Citizen Eco-Drive watch is made like this. If you want something fancier than the Casio WS210H, get an Eco-Drive and follow the same rules as you would with the Casio. Just don't put it in the dark for long periods and the battery can last a very, very long time.

And do the tide graph and moon phase functions work?

Published 2020 Aug 10