Supply power to a Raspberry Pi or Pi 2.
Tips on powering your RPi for 7+ hours from a battery
Instructable about Automated Recording Unit Pi (ARUPI) for Soundscape Ecologists
An uninterruptible power supply for your Pi2
Mobile Pi and data logging for Raspberry Pi.
Tweak your Pi to use less power and last longer on battery
Power your Raspberry Pi from AA batteries
A simple Arduino battery tester circuit tutorial!