Solar Post Cap Light with Bubble Lens 10 Lumen - Features durable plastic construction with a black coat finish. During the day the solar panel charges the battery creating electrical power. At dusk the solar panel, sensing the absence of light, turns on the solar garden light using the electricity stored during the day. The more sunlight the fixture gets, the stronger the charge will be and the longer your fixture will illuminate at night. Solar panel should receive 8 Hours of sunlight for optimum performance.