I am thinking of running the arduino with a 9V b attery indeed..
The arduino is basically connected to a 16 by 2 LCD display, a RTC module, 2 push buttons and a servo. But the servo runs on its own battery source. so, the arduino powers everything else other than the servo. The servo rotates 180 degrees every 4 hrs per day max. And the LCD display sleeps after inputs have been transferred to it via the pushbuttons and only wakes up when the pushbutton is pressed again or when the battery gets low...
So if this is the case, any idea how long the 9V battery would last?
Or any other portable and not too expensive suggestions other than http://www.batteryground.com/product/3/382/One-96v-2000mah-Nimh-High-Capacity-Battery-Pack-For-Rc-Car-robots.html ?