These are awesome! I've had them for a couple of years now, and they work great. You do need direct sun to get the best charge, and of course, all of my front-facing windows point north and get little direct sunlight. So I rotate mine - I have a couple charging in a window that gets full sun, and I swap them out for the ones that don't get direct sun. I just have them sitting on the sill, not suctioned in the windows. Works well (as long as I remember to do it :) ) If I forget the candles do have a bit of a charge, but they don't last long. But I *love* not having cords!