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.
Wake-on-Shake Hookup Guide
A basic hookup guide for getting started with the SparkFun Wake-on-Shake. The board gives you the ability to put your project into hibernation until bumped or shaken awake using the ADXL362 accelerometer. This means you can design projects meant to stay inert for long periods of time, possibly even several years, depending on the battery type used to power the project.
How to Build a Remote Kill Switch
Learn how to build a wireless controller to kill power when things go... sentient.
ESP32 Thing Power Control Shield Hookup Guide
This tutorial shows you how to get started with the ESP32 Thing Power Control Shield.
Beginner Parts Kit Identification Guide
The essential parts for beginning (or even experienced) hobbyists that gives you all of the basic through-hole components you will need to get started playing with embedded projects. We'll identify a few parts in the kit and provide a few basic circuits to get started!