Product review (5 stars): Outstanding
I waited to post this review until we had a chance to put the Knox Gear 48 Quart Electric Cooler/Warmer with Dual AC and DC Power Cords (Blue) to the test.
We took this cooler on a 10 day road trip (5,700 miles) out to the midwest and it performed perfectly.  I followed others recommendations as to plugging it in a few hours prior to filling it and also put already cold items in it.
It was wonderful to have cold beverages and some other snacks available throughout our trip.  We took it into our hotel room at night and back into the car as we traveled through yellowstone and many other places.  Our vehicle does shut down auxiliary power sources when the vehicle is not running, but if your vehicle does not you should unplug the cooler to keep it from draining the battery.  There were short periods of time where the cooler sat in the car without running and it continued to keep the food and beverages cold.  We would add warm temperature items along the way and they become chilled thru our journey.  If you are expecting ice cold be warned it only cools to about 40-45 degrees.  But the fact we never had to stop for ice or drain the cooler was wonderful.  If I had any complaint which is a minor one it disperses some heat while running but that's to be expected.  It is very quiet and never created any issue for us.  It cleaned up and looked brand new after a good solid performance.
And the seller was prompt in getting it shipped out and delivered as promised.
Nothing but satisfaction for us!