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.
Battery Technologies
The basics behind the batteries used in portable electronic devices: LiPo, NiMH, coin cells, and alkaline.
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.
Qwiic Single Relay Hookup Guide
Get started switching those higher power loads around with the Qwiic Single Relay.
Power Delivery Board - USB-C (Qwiic) Hookup Guide
This guide will go over how to use the USB Type-C Power Delivery Board.