It took me 2 days to figure out that it will not work when inside the rear window of the car. But, once i had it in direct sunlight the little red LED came on and i was filled with happiness. After a day in the sun i managed to get it to flash twice with charge. This far below the 5 that it should have had as advertised for the near 12 hours of sun it got; with clear blue sky. I gave it another full day and got it to 3 flashes and then charged a phone to full, then my N810. The phone was just fine but the N810 looked to charge too fast and is losing charge far quicker than normal. I conculde that the solio is useful, but device charging needs to be planned around the long charge time, also take it with you fully charged from your computer and you should be fine.