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.
FemtoBuck Constant Current LED Driver Hookup Guide v13
The FemtoBuck board is a high-efficiency, single-channel constant-current LED driver.
LiPo Charger Plus Hookup Guide
This tutorial shows you how to hook up and use the SparkFun LiPo Charger Plus board.
Power Delivery Board - USB-C (Qwiic) Hookup Guide
This guide will go over how to use the USB Type-C Power Delivery Board.
How to Run a 5V Device On a 3.3V System With Qwiic
Power up your 5V I2C devices on the Qwiic system! This tutorial shows you how to use the SparkFun Qwiic 5V Boost to integrate power-hungry sensors like the SEN55 seamlessly.