I have a design where I use 4 regular C batteries and the voltage regulator shown in the link below and it all works nicely. But the output voltage is 3V not 5V.

For your particular design, I would use 2 regular 9V batteries with a 5V regulator. Or even better if physical space allows it, I would use 6 AA batteries. The theoretical average capacity energy for two 9V batteries is about 41000 Joules, and for six AA batteries is about 92340 Joules. So, six AA will last you longer.


http://www.mouser.com/Search/Product...1185-3.0VCT713

Robert