Pins stop working on Motorshield R3

Okay, yes, I see now that I certainly confused the capacitance with the current.

Based on my last post I went out and bought a pack of 100 ohm resistors. I was going to move the laser over one pin, put a 100 ohm resistor on in the line, crack open a beer and hand out high-fives, but now I'm thinking that isn't a great idea.

How do I find the "response curve for the laser diode" and the internal resistance of the battery so I can "intersect" them?