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.
Qwiic Quad Relay Hookup Guide
SparkFun’s Qwiic Quad Relay is a product designed for switching not one but four high powered devices from your Arduino or other low powered microcontroller using I2C.
Power Delivery Board - USB-C (Qwiic) Hookup Guide
This guide will go over how to use the USB Type-C Power Delivery Board.
IoT RedBoard ESP32 Development Board Hookup Guide
Delve into the functionality-rich world of the IoT RedBoard ESP32 Development Board!