I modified my WH41 for contiunuos power from my solar panel system (2 x 100W panels, one on other side of shed not shown in pictures) with an 80 amp hr battery and 40 amp MPPT Rover CC. Using a 10 ft USB cord, I drilled a small hole on the bottom of the WH41, I put a glob of silicone caulking to close the hole after feeding the USB cord, and plugged the unit to my solar controller output. The solar controller provides power for some landscaping and security lights and USB ports at night, where I have the WH41 plugged in.
I'm thinking to WH41 is more better suited for this mod than the WH43 because the USB port is at the bottom versus the side. The former is more easy to weatherproof.