I'm not sure how well these will work, but I'm hopeful. Right out the box and turned on, one of them worked fine. 
The other one has yet to come on and it's day 2. I know they need to charge, so I'll give it a few more days. 
Currently the only down side I see is where the battery is located. It's right behind the light that can't be removed.  Also, when getting it to stick to the window, you have to flip the suction switch.  That too me a minute as I didn't read instructions.  but if it all goes well, I'll order another few sets. they should look really nice in the window for the winter holidays.
Update: removing 2 stars!
have had them about 2 weeks and both have stopped working. I've left them charging days in the sun. Nothing.  So, I purchased battery operated ones from a local store today.