Apparently I'm not the only one to think of it. But this project isnt waterproofed

https://www.instructables.com/id/Solar-charging-ereader/

My use case is for backpacking. I have the charging case for my k4

https://www.amazon.com/gp/product/B006E95V8M/

But it weighs too much, and i want the touch screen and more storage. Hopefully, there are enough people reading on the beach to make a profitable niche market