Did you know, you can’t glue pieces of styrofoam together using Elmer’s Glue? I did”t. A bottle of that shit costs over a dollar, and unless you are gluing paper, it’s wortless.
Go ahead and add another dollar to the crap category for RoboFridge. 
Elmer’s Glue Sucks
Published: March 31, 2004Posted in: Life Sucks
About the Author
Straight up, next level bullshit. 
Put the Elmers glue away. I got just the thing youre looking for. I have an mega-insulated styrofoam container that will hold a 6-pack and has a lid and everything. I get them from work because they pack them with dry ice and use them to send frozen fetal bovine serum through UPS. Check out the pictures below. Ive also got 3 Peltier elements (they were originally $20 apiece, but I got them free from work). Theyre yours if you want them.
Anyway, Peltier elements suck major current as you know. I think that youre going to have to have a bigger supply than just a battery unless you want the thing to be HUGE. (Were probably talking about a car or fork-lift battery here.) Anyway, it seems to me that a good alternative would be to just have the thing sit there and be plugged into a power supply (maybe some sort of docking station) when its not in use, keeping your beverages cold. Then when you call for it, it can disconnect from the power supply and use battery power to move to you with the peltier elements turned off. The cooler that Ill give you will keep your beverages more than cold enough for the short time it will take the robot to get to you. Otherwise, you are going to have to get a battery that can handle the peltier elements, DC motors, and microcontroller all at the same time.
Harvesting the biproducts of bovine fetuses,
Adam