So, actually if I used a sensor that didn't need 5v e.g.,touch sensors, I could technically build a circuit without a voltage regulator as long as my solar cells outputted less than 5.5v with a load?
I wasn't really sure how to analyze the chart because there's such a huge difference between the free current and stall current. I was worried that the motors would be drawing something a little less than the 5v - 420mA stall current each? That would eat up my power pretty quickly.
Also is the RPM's listed just the rotations per minute? Because even free spinning, I can't believe that one of those motors can spin at 31,900 RPM with 5V. That's 532 rotations a second!