parts cost: 15$
find them on ebay or similar, I don’t want to promote anyone, this is free advice.
12$ for solar cells ( 5×5” C60 cells from Maxeon, same are on Solar Impulse1 plane!) each is around 3W, so for 10 that is 30W
3$ for DC-DC buck converter (converts variable DC voltage to fixed DC)
connect cells in series, and you set converter to 17.3V and that s it! (for ph2, set it to 12.6V!)
have fun!
charging takes around 90 minutes.
music:
“Inspired” Kevin MacLeod (incompetech.com)
Licensed under Creative Commons: By Attribution 3.0 License
http://creativecommons.org/licenses/by/3.0/
Post time: Feb-11-2017