Paul, surprizingly its been decent here the past few days, but Saturday its suppose to be back to normal temps 90's-100's, there is a car/airplane show at KUUV Sullivan MO , I will be giving it the test then, I have it connected to a small 12 volt battery so its not hooked to the aircraft system, the battery is 4 lbs of the 13.2 lbs total, i could run a cigarette light plug off of it but opted for a portable set up for now, I ran it for 2 hrs last night, it held the 50 degree outlet temp with ambient temp at 75