The goal here was to capture images intermittently and reduce power consumption. The following stats are all for a headless, HDMI disabled, RPi Zero W connected via SSH on Wifi. This is using a Purethermal 2 board and a Lepton 3.5 Here are the results:
0.098 A - Idle and purethermal2 is unplugged
0.175 A - Idle, now the purethermal2 is plugged in
0.340 A - There is always a brief spike when the shutter operates
0.250- 0.300 A- When running script that streams constantly from camera
0.185A for 9 seconds, 0.240A for less than 1 second @ when running script that takes output every 10 seconds
Using exactly the same setup and a Lepton 2.5, the results are almost exactly the same, except it seems like the peak current is a little less ( ~0.23A) and duration of the higher current for running is also less.
Once I get the image capture to work, we will save power by periodically disconnecting from and turning off the Purethermal board which is a usb device. There are some forums that discuss generally how this is done:
Once it boots, connect via SSH and execute commands to update software. Also to save power, if you're going headless you can turn off the HDMI. This is the only non-thermal imaging or image processing related power hack here.