Help needed with project

Hi, its my first post... My name is Gonzalo and I stay here for all..;). Thank you for accept me.

Well, I am thinking about develop a little device with arduino nano. My problem its the device its portable and the more little possible. Please, How I can power arduino nano for most eficiency batery?. P.D.- I think to do the device rechargable.

Sorry for my english.. and thanks!

English is fine.

The rule is, if you describe what the project actually is, what you wish to do with it, what parts you propose to use, and give a brief and general description in your subject header by choosing "More" -> "Modify" to the bottom right of your first post here, instead of the meaningless "Help needed with project", then people will be able to assist you in the process. :grinning:

Adafruit powerboost 1000 + one of their Lipo batttries. Done.

-jim lee