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.
IoT Power Relay
Using the ESP32 to make a web-configured timed relay.
LuMini 8x8 Matrix Hookup Guide
The LuMini 8x8 Matrix (APA102-2020) are the highest resolution LED matrix available.
Single Cell LiPo Battery Care
This tutorial will go over how to safely charge, connect, disconnect, reinforcing the cables, and handle single cell LiPo batteries.