One day, I’d like to power a small remote server from solar power. Today is not yet that day. But I’m closer …
At the Solar Power International show (big modules! cheap modules! AC modules!!) last week in Orlando (squee-able minilizards! cuban food!!) there were a few vendors selling solar USB chargers. Most were folding thin-film units similar to this, but what caught my eye (and was actually for sale at the show) was the LSTech “Smart one“: 
The unit features:
- 2× 3.5 Ah 3.7 V Li-Poly batteries
- a 4W 5V solar panel inside the clamshell case
- a 1A USB output
- a USB Micro-B charging input and auxiliary solar panel input
- two ah-oww, make-it-stop bright LED
interrogationreading lights.
It comes with a couple of USB cables, and like seemingly all Korean semi-luxe electronic devices, comes in a soft brown velour bag. I’m not sure if the soft velour bag is the universal sign of quality in Korea, but I’ve noticed it enough that it might be A Thing.
I’ve run a Raspberry Pi for a couple of hours off this thing without making too much of a dent in the charge. I might be able to run it in full sun from the 4W solar charger, but I’m under no illusion that the Raspberry Pi’s ~3.5W continuous draw is going to keep running from such a small panel. That’s expecting an 88% capacity factor from a solar panel, which would be well if there wasn’t this small thing called night (or rotation of the earth, or cloud cover, or …)