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.
Electric Power
An overview of electric power, the rate of energy transfer. We'll talk definition of power, watts, equations, and power ratings. 1.21 gigawatts of tutorial fun!
LiPo USB Charger Hookup Guide
How to charge your LiPo batteries with the USB LiPo charger. Plus how to modify your charger to set the charge current.
ESP8266 Powered Propane Poofer
Learn how Nick Poole built a WiFi controlled fire-cannon using the ESP8266 Thing Dev Board!
SparkFun Qwiic Quad Solid State Relay Kit Hookup Guide
A Hookup Guide to get you started with the SparkFun Qwiic Quad Solid State Relay Kit (say that five times fast!).