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.
ESP8266 Powered Propane Poofer
Learn how Nick Poole built a WiFi controlled fire-cannon using the ESP8266 Thing Dev Board!
What is a Battery?
An overview of the inner workings of a battery and how it was invented.
TPL5110 Nano Power Timer Hookup Guide
The TPL5110 Nano Power Timer is ideal for applications that require low power, and especially those projects that are running off of a LiPo battery. The Nano Power Timer will turn on your project after the set amount of time, continuously.
Buck Regulator Hookup Guide
Get started with SparkFun's newest Buck Regulator Boards - the BabyBuck and the Buck!