I love the LITOM model I have. It can be turned on full time (dim or bright) or works with a motion detector. It has a light sensor as well, so it won't work until dark. It is very bright, thanks to the high capacity 18650 battery
(removable, replaceable). I added a small metal plate to the window using 2-way tape. I added button magnets to the light so it can be easily removed and put in the sun or stored away.
I bought mine on Amazon (search: LITOM). They have several models. I'll attach a picture on the one I bought.