PiPower information site

Run your Raspberry Pi project off-grid
Make it resilient to hardware and software bugs or "glitches"
Have full control..

    Efficient 5V, 3A switched-mode power supply
    Solar charge controller
    Power-off to avoid battery deep-discharge
    Heart-beat triggered power reset
    PICAXE microcontroller based - functions can be modified by the user
    Plugs onto the Raspberry Pi GPIO header (although can be used with any device requiring 5V)

Download the documentation here
Download the latest version of Raspberry Pi board communication software here
Download the latest version of the PICAXE code here

Raspberry Pi is a trade mark of the Raspberry Pi foundation. The boards and the foundation are excellent. Go and buy one.