USB / DC / Solar Lithium Ion/Polymer charger & high capacity

[bicknell]

I'm pondering a Raspberry Pi project, but I need to figure out a few things before I can move forward with it. One is solar power for the Pi. Given I'd like to fit the whole thing in a shoebox sized enclosure when done, some sort of Lithium-Ion or Lithium-Poly battery seems like the solution. However, I then need a solar panel and charge controller.

Searching I found https://www.adafruit.com/products/390 which almost fits the bill, except that I think the batteries shown with it are too low capacity, and so are the solar cells. I don't see a maximum wattage for the controller board.

I'm afraid I need something much larger for the Pi, but not big enough to switch over to more traditional 12v "small solar" systems with like an AGM battery.

Is there any interest in a up-rated kit for the Pi? I'm thinking enough battery to run it for 24-36 hours on battery, and enough solar wattage that should fully charge the batteries in on a typical day and the controller to make it all work. Maybe even output it on a 1000ma capable USB port so a short cable is all that's needed.

[adafruit]

This design will not work with 12V panels, it will ONLY work with 6V. For more details of what the charger can do, please read the datasheet linked from the product page. We have no plans to make a 12V version

[bicknell]

Ah, missed the data sheet. Looks like the controller you're using is rated for 1.8A, which at 6V means about 10W.

So I'm thinking to "max it out", 3 of the 3.7w "large" 6v panels in parallel on the input would be ok. The Pi would take 750ma of that, so about 1A could go into the battery for ~5-6 hours a day, or 5,000-6,000mAh. A pair of the 6,600 batteries in parallel could provide that with only 50% discharge.

But that means there would only be enough battery to power the Pi for ~8 hours, so 24x7 runtime won't happen.

A board with 2x the capacity would get the job done, I think, if my math is right.