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.
LTC4150 Coulomb Counter Hookup Guide
A "Coulomb Counter" is like a gas gauge for your battery. Here's how to use it.
Adding a Timed Button to a Project
This tutorial will walk you through making a timed power controller for interactive projects. You will learn how to add an on button that will provide power to your project for an amount of time and then turn off again.
SparkFun RTK Express Hookup Guide
Learn how to use the enclosed RTK Express product to achieve millimeter level geospatial coordinates.
Single Cell LiPo Battery Care
This tutorial will go over how to safely charge, connect, disconnect, reinforcing the cables, and handle single cell LiPo batteries.