I was at a campground where the outdoor restrooms have a solar panel on
the roof, wired to indoor LED lights, which operate with a motion
sensor, when someone enters the restroom. It was very practical and
provided a lot of light. The lights had 24 LEDs in each fixture. The
batteries were inside the lights, since I did not see any external ones.

I'm wondering if this was home-made, or do they sell setups like this?
Have any of you seen such a lighting setup sold anywhere?

I'd like to install thus sort of thing in a shed.