The bare board should pull between roughly 3.5 and 6 watts DC, or between 0.3A & 0.5A @ 12VDC, depending on its activity level. You can save a bit of power by removing the Wifi module if it's not needed, and disabling the SAM3X (Arduino Due) CPU by holding it in Reset state, if that chip isn't being used (echo 0 >/sys/class/gpio/gpio0/value); if the SAM3X is used for a sketch, look into that chip's deep-sleep BACKUP mode if the application is suitable. See my posts in this thread for more detail: https://www.udoo.org/forum/threads/unattended-quad-battery-saving-for-forever-running-machine.8461/ Downclocking the main i.MX6 CPU (e.g. switching to powersave governor) doesn't yield significant savings, since unlike on an x86 PC, its core voltage remains fixed at 1.2V regardless of clocking. Of course any attached USB devices, Arduino shields or other hardware can draw additional power. The Udoo's DC/DC regulators for 5V and 3.3V are rated at 4A output each, a lot more than its onboard circuitry would normally draw-- in particular, hardly anything uses the 5V supply, but maxing it out with external boards or devices could increase 12V power demand by as much as 20W. The HDMI-to-VGA converters pull about 1W; I got rid of this load when my displays weren't being used by modifying the converter to run from 3.3V rather than 5V (this gets downregulated to 1.8V anyway), and drawing the 3.3V from a MOSFET-switched source on the LCD connector that's controlled by a custom screensaver. Of course using a native HDMI display avoids this problem, but I wanted to preserve a legacy setup driving three monochorme displays in different locations via analog VGA (one each from R, G and B, splitting the sync lines).
