These Solarek Solar Landscape Lights can automatically detect surrounding brightness - it enters charging mode to convert sunlight to electricity that is stored in the 1800mAh rechargeable battery in daytime, it automatically lights up at night. It has 3 brightness modes, so you can adjust to a desired mode by pressing the back button. Its solar panel with 19% high photoelectric conversion can effectively absorb the sunlight on the day and convert sunlight into electricity to fully charge the in