JoyTech 5pcs 0.16w 4v 40mA Mini Solar Panel Module DIY Polysilicon Solar Epoxy Cell Charger B004 PORTABLE ---- Mini solar panel, compact & stylish size, easy to be held, can be easily taken to outdoor activity. HIGH QUALITY ---- High quality epoxy resin, unique technology to make the components beautiful and strong, anti-wind and snow, increase the service life of solar panels. DIY YOUR OWN SMART MODEL ---- Build your own powered models, solar toys, solar lights, solar displays, charging small DC batteries. It can be used for teaching purpose. Many of our customers come from school, colleague, etc. EDUCATION ---- Solar panels are devices that absorb sunlight and convert solar radiation directly or indirectly into electricity through photoelectric or photochemical effects, it's perfect devices for science project. CONNECT SOLAR PANELS IN PARALLEL OR IN SERIES ---- When the voltage of your solar panel doesnt satisfy your storage battery, you can take two or more same solar panels together in series. Such as, two 5.5v solar panel connect together in series, so its voltage is 11V. When the voltage of solar panel satisfies your storage battery. In order to speed up the rate of charge, you can take two or more same solar panel together parallel connection.