Power Update:
I ran some multiple test using different supplies, I'll make a chart tonight sometime.
I found the 5V 7805 voltage regulator could only handle a 12V source for about 45mins before it overheats and shuts down (a safety feature built in). I think it would be great for only up to a constant 7V input.
I however, hacked apart a cheap USB car adapter (similar to: http://dx.com/p/universal-usb-power-car-adapter-black-27331) , which included some resisters, capacitors, etc. with 12V in, 5V out,0 max output of 1A. It lasted over 2 hours with the 12V source and didnt shut down. Adds a bit of extra bulk to the battery to controller but since it's already built it saves some times and convenience.