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.
Battery Technologies
The basics behind the batteries used in portable electronic devices: LiPo, NiMH, coin cells, and alkaline.
Sunny Buddy Solar Charger V13 Hookup Guide
How to hookup the Sunny Buddy: a solar-powered, MPPT (peak-power tracking), LiPo battery charger.
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.
Thing Plus Dual-Port Logging Shield Hookup Guide
This tutorial shows you how to hook up and use the SparkFun Thing Plus Dual-Port Logging Shield.