[DonRotolo]

For power, set it up to operate on either 12 volts (then use a 110 power supply) or 110 volts (then use a 12 volt to 110 volt inverter).

For coolness, you can use a classical refrigeration system (but heavy, relatively fragile) of Peltier devices (limited capacity for cooling, especially freezing). Peltiers need heat sinks, cooling fans and have a limited temperature differential, possibly requiring stacked units for the temperatures you want.

Real water ice has a lot going for it. 10 pounds of it can take 288 ounces of liquid from 90 F down to 34 F in about an hour, and hold it there (in a commercial ice chest) for easily more than a day. The energy required to change phase from solid to liquid is considerable, so you are storing quite a bit of energy in that solid water - more than you might get out of a comparable weight of battery. The byproduct - water - is generally environmentally compatible.

Don