Best way to power the Yun from battery?

I've got a Yun project that I need to power through a battery, so that it can be usable while disconnected to my computer.

Any pointers on how to do this? Its been said here before to make sure not to provide more than 5V of power to the Yun or risk damaging it. To prevent that I have access to a 5V step-down converter from Adafruit:

My background is in programming, so I'm a little new to the electronics aspect of this. Looking for any suggestions on why types of batteries to use - what voltages, what currents, etc. Any links to adafruit or sparkfun would be great.

Thanks for any help!

What kind of battery? A big one! The Yun is not very power efficient and is not a good candidate for battery power.

It's impossible to give a more meaningful answer than that without a lot more information. How long do you want it to run on battery power? What will you be doing with it? Will you be using WiFi? What shields and loads do you have connected to it?

Quick and dirty calculation: measure the 5V supply current the Yun is drawing when you are doing what you want to do with it. Take that value in Amps, and multiply it by the number of hours you want to run. That gives you an Amp hour (Ah) value. Now double that value, and find a battery rated at double that value. The doubling allows for approximately 80% efficiency of the converter, using 80% of the battery capacity so you don't totally kill it, and then a little fudge factor to be conservative. Of course,you can do much more sophisticated calculations, but that will give you a tough idea of what you need - I'll bet the battery turns out to be a lot bigger than you expect.

Yun takes around 300mA without anything added to it, so battery power is not practical

@Shapeshifter @mikeruss,

We've had this question before several times. I seem to recall the drain was less than 300mA (230mA if I recall right). However, if an good size battery was found, I believe the system could run almost 8 hours.

Sorry, I have no notes from these conversation. Your thoughts.