Logitech K760 Solar bluetooth keyboard. Not cheap, but frikkin awesome!
Not only does this baby have proper (and proper sized) mechanical feeling keys, it also supports toggling between 3 different Bluetooth connections, and amazingly doesn’t require any charging or replacement batteries!
It doesn’t actually have any ports to charge from – just a very good sized solar panel. It claims it gets plenty of charge just off the solar (even in an office), and can last for months on the battery even without the ability to charge.
I’ll admit I have a soft spot for Logitech since their wired mouse days. They were always high quality – one of the few things that would last past the warranty period, without fail.