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.
Uh-Oh Battery Level Indicator Hookup Guide
Learn how to assemble and use the TL431 in the Uh-Oh Battery Level Indicator Kit.
ESP8266 Powered Propane Poofer
Learn how Nick Poole built a WiFi controlled fire-cannon using the ESP8266 Thing Dev Board!
12V/5V Power Supply Hookup Guide
In this tutorial, we will replace the 12V/5V (2A) power supply's molex connector with two male barrel jacks adapters.
Fuse Breakout Board Hookup Guide
Protect your project by adding a fuse in your circuit to save it from molten destruction.