40W 12V Solar Panel Kit 60A/100A Battery Charger Controller Camping RV Caravan Boat
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Just a small pannel. Don't expect too much. It will charge a older smartphone with 2000mah lipo battery directy connected to the pannel's usb but it struggle for hours with a 4000mah mobile phone. You should opt for the dual panel setup and use a battery with the contoller if you wanna have some better results. The pannel outputs up to 300 milliamp in direct sunlight only and temperatures up to 28 celcius. When things get really hot the panel cannot deliver.
It works. Hardly 40W power from this panel is possible. I think 10-15W are more realistic numbers. One can estimate it from 1 kW per square meter of Sun power under proper conditions. Panel is approximately 0.2x0.4=0.08 square meters. For 20% efficiency one gets 16W of electric power, for 15% - 12W, etc.