My vehicle is partially used only once a week, which is why a trickle charge to the battery, especially in winter, is desired. That makes this panel as well. In full sunlight not only the basic consumption is covered, but the battery a little loaded (test gauge between the battery and the negative terminal disconnected).
In recent days has now occurred to me several times that the LED indicator is no longer illuminated, even though the sun radiates fully in the current Super weather. The panel (stored on the dashboard) was so hot that the finger has almost burned if you have touched the frame; the connecting cable is also much more flexible by the heat, as if everything is cold. And precisely in this state there is either directly at the terminal in the panel or on the cable strain relief on the contact problem. As soon as you slightly presses on the housing or some wobbles on the cable, the LED lights up again and also a gauge again shows supply of electricity to the plug. In a solar panel, which is made exactly for this purpose, I expect, however, that I may put it in direct sunlight.
Therefore now return to Amazon. Hotline promised me a credit. I am going to order a panel of another manufacturer and we hope that as the quality is better.