Reducing Arduino Power Consumption
Contributors:
Alex the Giant
Alex the Giant 
Resources and Going Further
More information on low-power modes and options can be found in the datasheet for the 328P.
For more power-related fun, check out the following SparkFun tutorials.
Reducing Arduino Power Consumption
A tutorial about different ways to reduce the current draw for your next Arduino project the easy way.
Nuclear Battery Assembly Guide
How to put together your BYOT (Bring Your Own Tritium) Nuclear Battery Kit!
smôl Power Board AAA Hookup Guide
Small in size, small on current draw. It's a smôl world! This guide will get you up and running with the smôl Power Board AAA.
Breadboard Power Supply Kit 5V/3.3V Quickstart Guide
Quick start guide for the Breadboard Power Supply Kit 5V/3.3V