Here's a fairly useful article: http://hwstartup.wordpress.com/2013/03/11/how-to-run-an-arduino-on-a-9v-battery-for-weeks-or-months/ http://hwstartup.wordpress

Here's a fairly useful article: http://hwstartup.wordpress.com/2013/03/11/how-to-run-an-arduino-on-a-9v-battery-for-weeks-or-months/ http://hwstartup.wordpress.com/2013/03/11/how-to-run-an-ardu...