How do u power a mini fridge?

Depends on the fridge. Truck fridge is usually direct wired and runs off the apu. Dorm fridge is usually plugged in to the inverter.

 

I have an RV fridge in my truck, plugs into a 12v “cigarette lighter” style socket. Previously, I had a little dorm fridge that plugged into my inverter.

 

Inverter is how i have always had my fridges powered. My last rig had this setup. Nice HE dorm fridge on a 2500W inverter. Just gotta turn it off if you leave the truck off more then a few hours if you dont want to risk a dead battery.

 

My truckfridge is a direct 12v connection to a factory connector...my company doesn't believe in APU's. It's just wired thru the low voltage cutoff so it won't drain your batteries completely.

 

That depends on what your company is doing, many do, some don’t.

 

What is the minimum inverter size needed to run a “dorm fridge”?

 

It depends. How many watts does the fridge pull at peak? how often does it run? are you doing 12V to 120V or a hard wired inverter? How efficent is the inverter?

As a rule though i wouldnt recomend anything below 800 and a 1500-2000 watt are by far the best bets as they will ensure the fridge wont peg the inverter even if you get a less efficent one as well as let you do stuff like charge a laptop or run a small TV or microwave.