Hi - I'm trying to create a mobile imaging set up using an ASI1600MC Cooled camera, and a 120mm-S, controlled by The Sky X on a raspberry Pi.
I have been measuring the current and voltage input to the Pi - I found that unless I had a v high quality power cable, I was having problems.
I have found that as the power for the cooling for the ASI1600 cooled camera increases, more current is required by the Pi. Without cooling on, the Pi uses about 0.6A when running the camera. With the camera running at 100% power, I was surprised to see that the Pi uses about 1.5A.
Is this normal? I was not expecting more USB current to be required to run the camera, just current for cooling from the separate 12v supply.
When I add the autoguider and scope control, I get about 2.4A, which is well over the spec of 1.6A for the Pi.
I'm not using a Raspberry Pi, but I can tell you that my ASI1600MC-cooled camera uses about 0.22A from my Android tablet USB port when the camera is active, but that drops to zero when I plug in the 12VDC power cable for the cooler.
So, I believe the camera uses the 12VDC as the sole primary power source to reduce drain on the USB host! That is a great thing!
Keep in mind that ZWO states the camera cooler should be driven by a 2A or even greater 12VDC power source. That may explain the load on the R-Pi you are seeing.
I hope this helps,