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.
Measuring Internal Resistance of Batteries
Classroom STEM activity that has students build a battery from a lemon, measure the open and closed circuit voltages, and determine the battery's internal resistance.
Qwiic Single Relay Hookup Guide
Get started switching those higher power loads around with the Qwiic Single Relay.
LuMini 8x8 Matrix Hookup Guide
The LuMini 8x8 Matrix (APA102-2020) are the highest resolution LED matrix available.
Buck Regulator Hookup Guide
Get started with SparkFun's newest Buck Regulator Boards - the BabyBuck and the Buck!