I have the fairy lights for several days charged in the apartment (switch in Off position, as prescribed in the instructions). On the first day the lights shone even very nice. On the second day a bit weaker, and today, on day 3, they unfortunately no longer light up. It's been days foggy but still it was quite light today and our terrace is also usually sunny, also are the solar panel at 3 different locations, so at least one should have but gotten enough light. Even through the snow, they are not yet covered.
So from beautiful Adventsbeleuchtung despite the lack of outlet unfortunately was not, with us it is now dark on the terrace. :-(
Update: it was now slightly sunny in the last days. The lamp does not light up even slightly to 18 clock. I'm still not impressed. Another update: today it was all day springlike sunny. The lights have held up almost 20 clock. So conditionally suited for spring, for the winter not.