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.
How to Power a Project
A tutorial to help figure out the power requirements of your project.
INA169 Breakout Board Hookup Guide
How to interface with the INA169 Breakout Board to measure current.
LiPo USB Charger Hookup Guide
How to charge your LiPo batteries with the USB LiPo charger. Plus how to modify your charger to set the charge current.
Nuclear Battery Assembly Guide
How to put together your BYOT (Bring Your Own Tritium) Nuclear Battery Kit!