CAN THE CFX3 KEEP FOOD COLD IF IT ISN’T CONNECTED TO A POWER SOURCE OR MY BATTERY DIES?

Yes. In our lab testing we found that the items in the cooler (12oz soda cans) warmed up at roughly 1 degree F per hour.  For this test the cooler internal temperature was 38F and the ambient temperature was 70F.  There were 24 cans in a CFX3 55.