We found a few interesting results when measuring the power drain of the Nest Cam. The most astonishing feature is the power down mode. The Nest Cam is working round the clock it appears - even when you tell it to shut down. The device current drain only changed slightly when we gave it the turn off command, reducing from 370mA to 340mA. Typically a shutdown or standby mode would reduce current by 10-100x. The power on LED on the device did turn off, (and that can account for most of the current reduction) so what is the Nest Cam doing after you turn it off, Google?
Related Device: Nest Cam