Casio Tough Solar Watches

CASIO TOUGH SOLAR watches draw their power from a newly developed ultra-small solar panel featuring highly efficient electric power generation and a large-capacity rechargeable battery.
Wearers enjoy unrestricted use of various watch functions - such as a full-auto backlight; advanced sensors for measuring the temperature, atmospheric pressure and direction as the watch recharges itself with solar energy.
Digital watches with LCD displays and various functions require considerably more power to operate than conventional analog watches. TOUGH SOLAR watches employ CASIO's original large-capacity solar-charging system to ensure the wearer unrestricted use of their advanced digital watch functions.
TOUGH SOLAR watches can be recharged even on cloudy days or under fluorescent lighting. The recharging speed differs depending on the brightness of the light source, but in optimal circumstances, outdoors on a sunny day (50,000 Lx), the solar battery can generate enough power for a day's operation in just 5 minutes. It also keeps on charging naturally during normal operation worn on your wrist. If the watch isn't fully exposed to light, however - as may happen when it's covered by coat or jacket sleeves, for instance - the charge level may fall too low. You can prevent this easily by exposing your watch to a strong light source, such as direct sunlight, to recharge it occasionally under such circumstances.
Once the battery is charged, the watch continues operating, even in the dark. A fully charged TOUGH SOLAR watch will keep running for a minimum of approximately five months, *even if it's worn in places with no exposure to light.
No. TOUGH SOLAR watches are equipped with an overcharge prevention function that prevents problems caused by excessive exposure to light.