I have my first arduino project running! Very exciting.
With my arduino nano powered by USB and my multimeter between +5v and Ground on the Arduino I get readings of: - 4.7v - 3.9mA
1 ) If I want my device to run for 4 hours how do I calculate the required battery? (is it just 3.9mA x 4 hours = 15.6mAh???) 2) I need to find a flat battery like a cell phone battery or coin battery to run this device. Do you have any recommendations? 3) If I combine two of these '3v / 2mA / 17mAh' batteries will that work? http://australia.rs-online.com/web/7020761.html or will I need to limit the 6v back to 5v some how?
Thanks for any guidance. Cruzah
PS. Device is a Arduino Nano, 16 x 2 LCD (no backlight), and a couple of buttons.