[DisasterRadio] solar battery manager

[Jake]

this might be the same thing Fitz already designed for the disaster radio
system, to manage solar charge and battery stuff, or maybe its design or
production could improve our situation, i don't know:

"Solar Power Manager 5V is a small power solar power management module designed
for 5V solar panel. It features as MPPT (Maximum Power Point Tracking)
function, maximizing the efficiency of the solar panel, suitable for various
solar power projects."

https://www.dfrobot.com/product-1712.html