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.
What is a Battery?
An overview of the inner workings of a battery and how it was invented.
IoT Power Relay
Using the ESP32 to make a web-configured timed relay.
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.
LuMini Ring Hookup Guide
The LuMini Rings (APA102-2020) are the highest resolution LED rings available.