Clearly a full day of direct sunlight was not called for to keep a light on throughout the night. It likewise showed that heavy quantities of shade could imply they do not last all evening.
This will, obviously, vary relying on the sort of light, type of panel, and also kind of battery. There is no single quantity of time or amount of sunlight that will certainly ensure your lights stay on all evening. I might give you some formula but the chances of that in fact being any type of usage are little.
A lot of makers assert that 8 hrs of direct sunshine will certainly give in between 12 as well as 15 hours of fee. So that is conveniently a complete night. But the fact is you aren't most likely to want to place all your lights in the middle of a lawn without any color. Yet if you can obtain 4 hrs of sunlight on them this will certainly give you a 6 to 8 hours charge which is a full summer season evening.