SharpCap will tell you the Cooling Power Percentage necessary to reach your -20*C Setpoint. If you are running the Cooling at 100%, then you ARE setting yourself for a Large Power Draw(12V @ 2A).
Remember that the DeltaT (Cooling Ability) of the ASI1600's TEC is rated as -40*C Relative Degrees, so unless the Ambient Temp was less than 20*C while Imaging then the Cooler would be running at a perpetual 100%. That level is definitely a Power Drain.
Make sure that you set the Cooling Setpoint to a realistic Number, so that the Cooler isn't running at more than 60-70% after the Initial "Cool-Down". Then your Power Drain will be MUCH Less.
Thanks...working on setting this up now for practice. Appreciate the advice.