Casio Solar Watches use the sun's rays to keep the battery powered via Casio's Tough Solar Cell.
This solar conversion cell enables the watch to charge the battery whenever exposed to indoor or outdoor ambient light.
When Casio Solar Watches are unused, they will automatically 'sleep' until disturbed or placed in light. Once activated, they automatically power up and display the correct time.
Selection of Casio Solar Watch features to look out for: