Why It Doesn't Work? For the solar lights, please note that the solar panel is very sensitive to any light source. If the solar panel can sense ANY light, it will change to the charging mode automatically and while it is charging, no power will be supplied.And it won't light up. So after fully charging the solar panel, (fully exposed to the sun for 5-6 hours), you can test it during the daytime by taking cloth or anything else that would prevent the solar panel from exposure to any light and then cover the panel. If you try it at night, make sure the panel does not face any light source directly. So please: 1、Prevent the solar panel from exposure to any light source 2、Press the ON/ OFF button to test if the lights can light up. Just put the solar panel in a sufficient sunny place,light from the sun charges the battery, and at night, energy stored in the battery powers the LED lights.No energy or electric costs. All the components are IP65 waterproof enabled, making it suitable for both indoor and outdoor usage. Send out multicolor light and creat a pleasant atmosphere for courtyard, lawn and tent 8 lighting modes including waves, combination, sequential, gradual, chasing flash, slow fade, twinkle flash and steady on When the built-in NiMH battery saves enough solar energy in the daytime, the string lights can automatically work for 8-10 hours at night No outlet required! Highly multifunctional, efficient, reliable, and extremely durable.