Casio · AQ-S800 series · Ref AQS820W-1AV
The big, plain one.
Casio’s largest cheap analogue-digital solar: 50.1mm across, 12.7mm thin, about 46 grams, with world time, two repeating timers and five alarms on module 5745. No red ring, no frills, no battery changes.
Charge & run
Battery level indicator and power saving
g-central.com; casio.com blocks fetches
52.5 × 50.1 × 12.7mm per casio.com
g-central.com
g-central.com
Plus 5 alarms and world time
Wider, thinner, plainer
Set the AQ-S820W beside the AQ-S810W and the differences are all in the numbers. It is 50.1mm wide to the S810W’s 48.3mm, and 12.7mm thick to its 13.7mm. It drops the red accent ring for an all-black dial and bezel.
The layout is the same idea: analogue hands and markers in the top of the dial, an LCD in the bottom third showing the time, day and date. It is a work watch rather than a design object, and the extra width makes both displays easier to read.
Module 5745
The module carries world time, five daily alarms, an hourly signal, a 1/100-second stopwatch and two timers that can repeat up to ten times, which is the feature intervals and circuits actually use.
It also shows a battery level indicator and drops into a power-saving mode in the dark. Those two features are what make a solar watch trustworthy: you can see the charge, and it protects itself when it is in a drawer.
What the resin buys
Case and band are resin, the crystal is mineral glass, and the whole watch weighs about 46 grams. Nothing on it will be ruined by a knock against a doorframe, and nothing on it was expensive to make.
The 100m rating covers swimming and showering. For a watch worn on a building site, in a workshop or on a bike, that combination of size, weight, solar power and water resistance is the entire pitch.
Specs
- Reference
- AQS820W-1AV
- Case size
- 50.1mm
- Movement
- Solar Quartz
- Caliber type
- Casio Solar Quartz
- Complications
- Analog-Digital Display
- Origin
- Casio (Japan)
Specifications as published by Casio. We research from manufacturer documentation and published sources rather than hands-on testing. Researched 2026-09-03.
Verdict
The largest of Casio’s cheap solar analogue-digitals, 50.1mm wide and about 46 grams, with repeating timers, world time and no battery to change.
Strengths
- Tough Solar with a visible battery level and power saving
- Two repeating timers plus five alarms and world time
- Big, legible twin displays at 50.1mm wide
- About 46 grams and 12.7mm thin despite the width
Trade-offs
- 50.1mm is one of the widest watches in this price band
- Resin case and band, mineral glass
- No red ring or design flourish; it is deliberately plain
- This entry links to a search rather than one listing, so check the exact reference
Buy it if
Work, outdoor and training use by someone with a larger wrist who wants the biggest display for the least money.
Skip it if
You have a small wrist or want anything dressy. The AQ-S810W is the smaller version; Casio’s MTP-S110 is the steel one.
FAQ
The AQ-S820W is wider at 50.1mm versus 48.3mm, thinner at 12.7mm versus 13.7mm, and drops the red accent ring for an all-black look. Both are solar-charged analogue-digital watches rated to 100m.
Sources
Researched and last updated 2026-09-03. We do not test watches in hand; every figure above is traceable to the manufacturer or the sources listed here.
Casio AQ-S820W Solar
Reference AQS820W-1AV
Prices and availability change; the band above is a research figure, so check the current listing.
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