Thanks for the feedback! I only did a bit of back of the envelope math and maybe tossed in some wishful thinking.
From their site:
Energy Consumption 12VDC (Ambient@90F, Internal@39F), [Ah/h] 1.43
Maximum DC input Ah/h: 9.6
So somewhere between 1.43 and 9.6. If I average those two, I get 5.5a. 46a/5.5a = 8.34 hours. If I use their math above to maintain 39F, I can run purely off the batteries for ~32 hours. I have this unit at home and it doesn't take that much power to maintain a chill since, first and foremost, it's a cooler. If you have to start from room temp, I can see it taking a lot of power to cool to 0F. I also have a set of Yeti icepacks that I toss in to help as "cold batteries"
If I'm being totally honest with my motivations, I wanted an electrical project to mess around with.