Solar powered USB help?
September 8, 2012 8:52 PM Subscribe
Calling all electrical engineers! Need some clarity on how to figure out solar charging rates and consumption of a USB device...
Ok, hivemind...I'm having a hard time keeping milliwatt hours and milliamp hours straight here, and I could really use someone with some electrical knowledge to keep me from going crazy.
I've got a USB powered device that the specifications say uses 5VDC/1.0A for power. I have been using a 6600 mWh rechargable Lithium ion battery to power the device when I need it to be portable (which is often) and it's been dandy...I regularly get 15+ hours of uptime from it. But now I'm looking at the possibility of a permanent outdoor home for this device, and thinking about how to make it run from solar cells.
Given the above, can you help me figure out how large a solar panel I would need to power the thing during the day and build up enough charge to last it through the night? For argument's sake, assume average sunlight levels for the US...not Arizona, but not overcast all the time either. Are we talking square inches or square feet here?
Any suggestions for how to put something like this together?