DEO_Nano as onboard system

Hi Guys,

I am still beginner in FPGA.
May i ask some suggestions?

Now, i am doing project with DEO_Nano ALTERA Cyclone IV.
I use QUARTUS II 10.1 and NIOS II.
I want to make my system as onboard system.
So, in the future i want to use battery as power source for my DEO_Nano board.
Then, my question is:
How to make my DEO_Nano don't need to be upload the program again at power-on and don't lose that configuration when the power goes off (battery as power source), but i still can upload new code to the board if i build new code.
So, it will be similar with others microcontroller.

Thank you so much for your help.