https://github.com/steveb1475/WeatherStation
I've been working on it off and on for a while, but I just started putting it up on github.
I'm also using the bme280 and am solar powering the whole thing. I haven't done a whole lot of testing on the charging and capacity, rough calculations look like I should be ok with a single 18650 Lithium-ion. For power management of the battery I'm using one of these:
http://www.banggood.com/USB-Lithium-Bat ... 24048.html
And I'm using a 5v boost converter from the output of the charging module. I'll upload more details to github soon.